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For permission to copy, contact [email protected] 2005 Geological Society of America 147

Geosphere; December 2005; v. 1; no. 3; p. 147–172; doi: 10.1130/GES00016.1; 11 figures; 6 tables, 1 animation.

An animated tectonic reconstruction of southwestern North Americasince 36 Ma

Nadine McQuarrie*Brian P. WernickeDivision of Geological and Planetary Sciences, MS 100-23, California Institute of Technology, Pasadena,California 91125, USA

ABSTRACT

We present tectonic reconstructions andan accompanying animation of deformationacross the North America–Pacific plateboundary since 36 Ma. Intraplate defor-mation of southwestern North America wasobtained through synthesis of kinematicdata (amount, timing, and direction of dis-placement) along three main transectsthrough the northern (408N), central (368N–378N), and southern (348N) portions of theBasin and Range province. We combinedthese transects with first-order plate bound-ary constraints from the San Andreas faultand other areas west of the Basin andRange. Extension and strike-slip deforma-tion in all areas were sequentially restoredover 2 m.y. (0–18 Ma) to 6 m.y. (18–36 Ma)time intervals using a script written for theArcGIS program. Regions where the kine-matics are known constrain adjacent areaswhere the kinematics are not well defined.The process of sequential restoration high-lighted misalignments, overlaps, or largegaps in each incremental step, particularlyin the areas between data transects, whichremain problematic. Hence, the value of thereconstructions lies primarily in highlight-ing questions that might not otherwise berecognized, and thus they should be viewedmore as a tool for investigation than as afinal product.

The new sequential reconstructions showthat compatible slip along the entire north-south extent of the inland right-lateralshear zone from the Gulf of California tothe northern Walker Lane is supported byavailable data and that the east limit of ac-tive shear has migrated westward with re-spect to North America since ca. 10 Ma.The reconstructions also highlight newproblems regarding strain-compatible ex-

tension east and west of the Sierra Nevada–Great Valley block and strain-compatibledeformation between southern Arizona andthe Mexican Basin and Range. Our resultsshow ;235 km of extension oriented;N788W in both the northern (50% exten-sion) and central (200% extension) parts ofthe Basin and Range. Following the initia-tion of east-west to southwest-northeast ex-tension at 15–25 Ma (depending on longi-tude), a significant portion of right-lateralshear associated with the growing Pacific–North America transform jumped into thecontinent at 10–12 Ma, totaling ;100 kmoriented N258W, for an average of ;1 cm/yr since that time.

Keywords: Basin and Range, kinematic re-construction, extension, plate tectonics, ve-locity field.

INTRODUCTION

The large-scale horizontal velocity field atEarth’s surface is one of the main predictionsof physical models of lithospheric deforma-tion (e.g., England and McKenzie, 1982).Two-dimensional, cross-sectional models offinite deformation of mountain belts incorpo-rating strong heterogeneity in rheologic pa-rameters have been developed over the last de-cade (e.g., Lavier and Buck, 2002; Braun andPauselli, 2004). Owing to advances in com-putation, fully three-dimensional models ofplate boundary deformation zones, incorpo-rating both horizontal and vertical variationsin lithospheric rheology, will soon becomecommon. Thus, a key observational frontierwill be the determination of precise displace-

*Current address: Department of Geosciences,Guyot Hall, Princeton University, Princeton, NewJersey 08544, USA.

ment vector fields of continental deformationin order to test these models. The most dra-matic recent improvement in obtaining suchvelocity fields has been the advent of space-based tectonic geodesy (especially using con-tinuous global positioning systems [GPS]),which is yielding velocity fields that are un-precedented in terms of both the scale of ob-servation and the accuracy of the velocities.These data have already been used as tests forphysical models in southwestern North Amer-ica (e.g., Bennett et al., 1999, 2003; Flesch etal., 2000) and elsewhere (e.g., Holt et al.,2000). Substantial progress has also occurredover the last decade in determining longer-term velocity fields using the methods of platetectonics and regional structural geology.

These longer-term displacement historiesare essential for addressing the question ofhow the lithosphere responds to major varia-tions in plate geometry and kinematics (e.g.,Houseman and England, 1986; England andHouseman, 1986; Bird, 1998) because suchvariations occur on the million-year timescale. Plate tectonics is a precise method forconstraining the overall horizontal kinematicsof plate boundaries, using seafloor topograph-ic and magnetic data in concert with the geo-magnetic time scale. For the diffuse defor-mation that characterizes the continentallithosphere along plate boundaries, however,tectonic reconstruction at scales in the 100 kmto 1000 km range is not as straightforward. Itis based primarily on structural geology andpaleomagnetic studies and requires the iden-tification of large-scale strain markers andconsideration of plate tectonic constraints(e.g., Wernicke et al., 1988; Snow and Wer-nicke, 2000; McQuarrie et al., 2003). Regionalstrain markers within the continents may notexist in any given region, and even if they do,they may not be amenable to accurate recon-struction at large scales.

148 Geosphere, December 2005

N. MCQUARRIE and B.P. WERNICKE

Figure 1. Schematic diagram illustratingthe method of using regional structuralconstraints to limit possible displacementpaths in tectonic reconstructions. See textfor discussion and explanation of letters.

In southwestern North America, a zone ofplate boundary deformation on the order of1000 km wide is developed along the plateboundary. In mid-Tertiary time (36 Ma), thisboundary was strongly convergent, with theFarallon plate subducting eastward beneaththe North American plate. Beginning at ca. 30Ma, the Pacific-Farallon ridge came in contactwith the North American plate. Since then, thePacific–North America boundary has grownthrough the migration of triple junctions alongthe coast. Now, the entire margin from south-ern Baja California to Cape Mendocino is atransform Pacific–North America boundary,rather than a convergent Farallon–NorthAmerica boundary (Atwater, 1970). Thischange in the configuration of the plateboundary is both relatively simple and pro-found, making southwestern North Americaan ideal laboratory for investigating how con-tinental lithosphere responds to changes in rel-ative plate motion.

Refined plate tectonic reconstructions haveprovided an improved kinematic model of thechange from convergent to transform motionand have shown that there were significantvariations in the obliquity of the transform af-ter it developed. In particular, during the in-terval ca. 16 to ca. 8 Ma, Pacific–North Amer-ica motion was highly oblique and included amargin-normal extensional component of asmuch as 2 cm/yr, coeval with a rapid pulse ofMiocene extension that formed the Basin andRange province (Atwater and Stock, 1998;Wernicke and Snow, 1998). At ca. 8 Ma,Pacific–North America motion changed tomore purely coastwise motion, which appearsto have changed the intraplate tectonic regimefrom profound extension to a more complexmixture of extension, shortening, and trans-form motion, responsible for the opening ofthe Gulf of California, thrust faulting of thewestern Transverse Ranges, and developmentof the San Andreas fault–eastern Californiashear zone–Walker Lane, respectively.

Over the last several years, high-quality,large-scale kinematic constraints, many ofwhich resulted from decades of field work andattending debate, have become available,reaching the point where synthesis into alarge-scale velocity field is feasible. A rudi-mentary kinematic model using many of theconstraints along the plate boundary and inthe plate interior was incorporated into a pub-licly available animation of the post–38 Maevolution of the entire Pacific–Farallon–NorthAmerica system (Atwater and Stock, 1998;animation available at http://emvc.geol.ucsb.edu/download/nepac.php).

In this paper, we synthesize the current state

of information on the kinematics of the dif-fusely deforming North American plate since36 Ma, based on offsets of regional structuralmarkers, and construct a strain-compatible ki-nematic model of the horizontal motions at 2m.y. (0–18 Ma) and 6 m.y. (18–36 Ma) inter-vals, presented as a continuous animation. Themodel is by no means a final product, as newkinematic information and testing will requiresignificant modifications of the model. Rather,the model is an attempt to be quantitativelyrigorous in a way that will be useful for com-parison with large-scale, three-dimensionalphysical models and for the identification ofissues regarding the structural kinematics thatmight not otherwise be detected. Thus, in ad-dition to the animation, we have constructed‘‘instantaneous’’ velocity fields based on 2m.y. averages from 0 Ma to 18 Ma and 6 m.y.averages from 18 Ma to 36 Ma. These resultsare our best attempt at ‘‘paleogeodesy,’’ pre-senting the geology-based kinematic model ina format similar to modern GPS velocityfields, which in turn may be quantitativelycompared to physically based model velocityfields.

METHODS

By combining regional structural con-straints into a single model, the self-consistencyof the model (i.e., its strain compatibilitythrough time) provides powerful additionalconstraints on the kinematics in at least threeways. The first and most important is the factthat high-quality local kinematic informationimposes severe constraints on its surroundingswhere information may not be available. As ahypothetical example, consider a large regionof oblique extension between two undeformedblocks (Fig. 1). The strain and strain path neednot be known for each geological element inthe deforming region in order to constrain thelarge-scale kinematics. If the sum of fault dis-placements across just a single reconstructionpath (p) is known, restoring point A to a po-sition at point B, and it is known that theblocks have not rotated, then the single pathimposes a strong constraint on the overall ki-nematics of all of the other paths between theblocks (Fig. 1A).

The second additional constraint is on er-rors in reconstructions. In the example in Fig-ure 1, let us suppose that the minimum valueof all fault displacements along reconstructionpath p restores the block to point B, but thereis no constraint on the maximum value alongthe path itself. The side of the block contain-ing A would overlap the block on the otherside of the rift if the displacement along the

path were in excess of AC (Fig. 1B), violatingthe condition of strain compatibility. There-fore, the displacement is constrained to be be-tween AB and AC, rather than some valuegreater than AB.

A third and perhaps most useful additionalconstraint arises when local constraints con-tradict one another. For example, if recon-struction along path q (Fig. 1A) required thatpoint A restore to a position D, which is wellwithin the other block, then the violation ofstrain compatibility forces reevaluation of thegeological constraints. The geological recon-struction for displacement along q, the paleo-magnetic constraints on the blocks, and thepresumed rigidity of the blocks cannot all becorrect. Thus, the exercise of regional recon-struction focuses attention on information thatis most critical for improving the accuracy ofthe reconstruction. For southwestern NorthAmerica, there is now enough high-quality lo-cal kinematic information that large-scale self-consistency of the model imposes useful ad-ditional constraints in all of these ways.

In making the reconstruction, the methodsused in the local study of Wernicke et al.(1988) and Snow and Wernicke (2000) in theDeath Valley region of the central Basin andRange province were applied at large scale. InSnow and Wernicke (2000), each step in thereconstruction showed the paleoposition ofexisting mountain ranges. Although the recon-

Geosphere, December 2005 149

ANIMATED TECTONIC RECONSTRUCTION

Figure 2. Map of western North America showing the primary tectonic elements in thereconstruction. The gray shaded polygons represent the physiographic or geologic ex-pression of mountain ranges, which in the Basin and Range are fault bounded and sep-arated by alluvial valleys. Dashed boxes are the locations of Figures 3–5. The numbersrefer to specific mountain ranges identified in Tables 1–6.

struction allowed for the ranges to changeshape as extension is restored (i.e., the rangesmay decrease in area), in our reconstruction,the mountain ranges are shown as digitizedpolygons that approximate: (1) the modernbedrock-alluvium contact (e.g., a typical rangein the Basin and Range), (2) faults boundingindividual crustal blocks (e.g., the Santa YnezMountains block in the western TransverseRanges), or (3) the physiographic boundariesof large, intact crustal blocks (e.g., the Colo-rado Plateau). In some cases, especially wherelarge extensional strains are involved, the re-construction overlaps individual polygons toaccount for extension, essentially using themodern bedrock-alluvium contact as a geo-graphical reference marker. Because the strainis extensional, and in the case of metamorphiccore complexes, one range has literally movedoff of the top of another, these overlaps do notviolate strain compatibility.

The individual positions of polygons wererestored in each 2 m.y. time frame through anArcGIS script that reads and updates a tablelisting the kinematic data for each range. Thescript, created by Melissa Brenneman of theRedlands Institute at the University of Red-lands, is written in Visual Basic and is incor-porated as a tool in a custom ArcMap docu-ment. The script reads a dBASE 4 table thatcontains the movement parameters (direction,distance rotation, and time interval) for eachrange (Appendix 1).1 The movement parame-ters listed in the table include both the avail-able data (Figs. 2–5), as well as the motionrequired for strain compatibility. For the re-gions where kinematic data are not available,the kinematics could be defined by insertingdata from proximal areas, or individual rangescould be moved by hand with the motion up-dated and recorded in the dBASE table usingthe ArcGIS script. The ArcGIS format and ac-companying script allows for exact displace-ments to be incorporated into the model, aswell as the individual adjustment of ranges toensure strain compatibility. The GIS script re-cords the geographical position of the centroidof each range at each 2 m.y. or 6 m.y. epoch.This allows for the data to be displayed in avariety of ways, including palinspastic mapsfor each 2 m.y. or 6 m.y. epoch, instantaneousvelocity vectors at each 2 m.y. or 6 m.y. ep-och, ‘‘paths’’ that individual ranges take over

1GSA Data Repository item 2005200, Appendix1, Movement Table, paleogeographic maps, andArcGIS files (shape files for each reconstructed timestep), is available online at www.geosociety.org/pubs/ft2005.htm, or on request from [email protected] or Documents Secretary, GSA, P.O.Box 9140, Boulder, CO 80301-9140, USA

the 36 m.y. span of the reconstruction, or ananimation that shows the integrated motionover 36 m.y. Instantaneous geology velocityfields are obtained from connecting the cen-troids of specific ranges at one time with thecentroid of the same range in a later time.

DATA

The primary tectonic elements in the recon-struction are large crustal blocks comprisingflat-lying pre–36 Ma strata, or geologic ele-ments that are otherwise little deformed, andthe straining areas in between them. The largeunstrained blocks include the Great Plains–Rocky Mountains region (nominal NorthAmerica reference frame), the Sierra MadreOccidental, the Colorado Plateau, the SierraNevada–Great Valley block, and PeninsularRanges block (Fig. 2). The strained areasaround them include the Rio Grande rift andBasin and Range province, the Gulf of Cali-fornia, the Transverse Ranges, the CoastRanges, and the Continental Borderlandsprovince offshore of southern California andBaja California.

The constraints used in the reconstructionare organized into six major categories (Tables1–6). The first covers a range-by-range recon-struction path across the northern Basin andRange near latitude 408N (Fig. 3 and Table 1).The second includes a similar reconstructionpath across the central Basin and Range nearlatitude 378N (Fig. 4 and Table 2). These tworeconstructions collectively constrain the mo-tion of the Sierra Nevada–Great Valley block.The third includes constraints from the south-ern Basin and Range, mainly the mid-Tertiarymetamorphic core complexes of the ColoradoRiver corridor and southern Arizona, west ofthe Sierra Madre Occidental, and extensionacross the Rio Grande rift north and east ofthe Sierra Madre Occidental (Table 3). Thefourth includes the complex Oligocene to re-cent strike-slip and extensional displacementsof the Mojave region, which connect the Si-erran displacement to regions farther south(Fig. 5 and Table 4). The fifth includes paleo-magnetic and geologic constraints on verticalaxis rotations of large crustal blocks, includ-ing the Sierra Nevada and Colorado Plateau,as well as small, individual ranges within the



Figure 3. Map of the northern Basin and Range showing the kinematic data incorporatedinto the model. Black numbers indicate horizontal displacement amount, red bold num-bers indicate age range of motion. Arrows indicate approximate magnitude and directionof individual relative displacements between polygons. Data compiled from Allmendingeret al., 1986; Armstrong et al., 2004; Bartley and Wernicke, 1984; Coogan and DeCelles,1996; DeCelles et al., 1995; Dilles and Gans, 1995; Faulds et al., 2003; Hardyman et al.,1984; Hintzi, 1973; Hudson and Oriel, 1979; Lee, 1999; Miller et al., 1999; Niemi, 2002;Niemi et al., 2004; Smith, 1992; Smith et al., 1990; Smith and Bruhn, 1984; Stockli, 2000,2001; Surpless, 1999.

central Basin and Range and Mojave regions(Table 5). Lastly, constraints on the large dis-placements along the San Andreas fault–Gulfof California shear system, and strains and ro-tations within the Continental Borderlands, in-cluding the large clockwise rotation of theSanta Ynez Mountains block, are included inFigure 6 and Table 6.

Northern Basin and Range

The extensional kinematics of the northernBasin and Range are dominated by two large-offset normal fault systems, the Snake Rangedetachment system (78 km of total offset) andthe Sevier Desert detachment (40 km of totaloffset). The Snake Range detachment systemaffects the Egan, Schell Creek, and SnakeRanges (Fig. 2, ranges 6–8). Although thecoupling of this system of faults to deep crust-al extension has been debated (e.g., Gans andMiller, 1983; Miller et al., 1983; Bartley andWernicke, 1984; Miller at al., 1999; Lewis etal., 1999), a magnitude of upper crustal exten-sion of 78 km 6 10 km, as determinedthrough mapped and restored stratigraphic

markers, is not controversial (Gans and Miller,1983; Bartley and Wernicke, 1984). Morecontroversial is the geometry of the exten-sional faults in the Sevier Desert basin (be-tween ranges 3 and 4, Fig. 2), including thevery existence of the Sevier Desert detach-ment, which is known only from interpreta-tions of seismic reflection profiles and welldata (Anders and Christie-Blick, 1994; Willset al., 2005). The 40-km offset along the Se-vier Desert detachment used in this paper isbased on restoring Sevier fold-thrust beltstructures that are offset by the detachment,and high-angle normal faults in the hangingwall imaged in the Consortium for ContinentalReflection Profiling (COCORP) and industryseismic reflection lines (Allmendinger et al.,1986; Allmendinger et al., 1995; Coogan andDeCelles, 1996). An opposing view to thelarge-offset kinematics of a shallow detach-ment suggests that the imaged reflection sur-face is a composite of aligned features thatincludes basin-bounding high-angle normalfaults, a subhorizontal thrust fault, and anevaporite horizon (Anders and Christie-Blick,1994). According to this interpretation, exten-

sion across ranges within and around the Se-vier Desert basin could be as little as 10 km(versus 40 km), which would subtract ;15%from our overall estimate of extension alongthe transect.

To the west of the Egan Range area, theremainder of the northern Basin and Rangedeformation is partitioned into extensional andright-lateral strike-slip offsets, both of whichaccommodate translation of the Sierra–GreatValley block away from the interior of NorthAmerica. The extension (94 km) is accom-modated by several systems of steeply tiltednormal fault blocks in the western Basin andRange, with individual fault systems accom-modating up to 16 km of extension (Fig. 2,ranges 13, 19, and 20) (Surpless, 1999; Dillesand Gans, 1995; Smith, 1992), and a numberof high-angle, presumably modest-offset nor-mal faults that define the Basin and Rangephysiography across the central part of the re-construction path, which we assume have 3–4 km of horizontal offset each.

Right-lateral shear is accommodated pre-dominantly through northwest-trending faultsconcentrated near the western edge of thenorthern Basin and Range in the northernWalker Lane Belt (Fig. 2, range 18). Right-lateral offset on a series of faults, which in-dividually have 5–15 km of offset, totals 20–56 km (Faulds et al., 2005; Hardyman et al.,1984). Because the faults strike more westerlythan the North American margin, their motionaccommodates a component of westward mo-tion of the plate boundary.

Timing of extension in the northern Basinand Range is constrained by a large body ofwork on the ages of faulted Cenozoic volcanicand sedimentary units and cooling ages of up-lifted footwall blocks. For example, the early‘‘core complex’’–related extension (ca. 35–25Ma) is seen in coeval faulting and volcanismat 35 Ma in the Egan Range (Gans and Miller,1983) and 40Ar/39Ar cooling ages indicative ofrapid cooling from 30 to 25 Ma in the westernportion of the northern Snake Range and from20 to 15 Ma in the eastern portion of the range(Lee, 1995). Apatite fission track (AFT) cool-ing ages from the northern Snake Range in-dicate 10–13 km of fault slip from 18 to 14Ma. Initiation of later ‘‘Basin and Range’’ ex-tension is seen predominantly in the fission-track and helium cooling ages of apatite andzircon. The cooling ages across the width ofthe extending zone cluster ca. 15 Ma (Stockli,1999), with 18 Ma ages in the footwall of theSnake Range detachment (Miller et al., 1999)(Fig. 2, range 6) and Sevier Desert detachment(Stockli et al., 2001) (Canyon Range, Figure2, range 3).



Figure 4. Map of the central Basin and Range showing the kinematic data incorporatedinto the model. Motion of the Sierra Nevada with respect to the Colorado Plateau in thisregion is predominantly constrained by two distinctive sedimentary deposits (indicated asstars and hexagons) offset along extensive normal and strike-slip fault systems. Arrowsindicate approximate magnitude and direction of individual relative displacements be-tween polygons. Black numbers indicate horizontal displacement amount, bold red num-bers indicate age range of displacement. Data from Axen et al., 1990; Brady et al., 2000;Burchfiel, 1968; Burchfiel et al., 1987; Cemen et al., 1985; Duebendorfer et al., 1998;Fitzgerald et al., 1991; Fowler and Calzia, 1999; Guth, 1989; Holm and Dokka, 1991,1993; Hoisch and Simpson, 1993; Niemi et al., 2001; Snow and Lux, 1999; Snow andWernicke, 1989, 2000; and Wernicke et al., 1988.

Central Basin and Range

The central Basin and Range province is inmany respects an ideal location for a province-wide restoration of Basin and Range extension(Snow and Wernicke, 2000, and referencestherein). A regionally conformable miogeo-cline, Mesozoic thrust structures and distinc-tive Tertiary sedimentary deposits tightly limitthe extensional history of both the Lake Mead(Fig. 2, ranges 22–25) and the Death Valley(Fig. 2, ranges 27–34) extensional systems(Wernicke et al., 1988; Wernicke, 1992). Mo-tion of the Sierra Nevada with respect to theColorado Plateau in this region is primarilyconstrained by displacements of two distinc-tive Miocene basins developed early in thehistory of the extension of each system (Fig.4).

In the Lake Mead system, restoring numer-ous proximal landslide breccias at FrenchmanMountain (Fig. 2, range 24) to their source

areas in the Gold Butte block (Fig. 2, range23) also restores piercing lines defined by thesouthward truncation of Triassic formationalboundaries by the basal Tertiary unconformityin both areas. The correlation of these featuresin the Frenchman Mountain and Gold Butteareas suggests 65 km 6 15 km of extensionbetween the two blocks (Fig. 4).

In the Death Valley system, Wernicke et al.(1988) initially proposed that the Panamintthrust at Tucki Mountain (Panamint Range,Figure 2, range 28) is correlative with the Chi-cago Pass thrust in the Nopah–RestingSprings Range (Fig. 2, range 27) and theWheeler Pass thrust in the Spring Mountains(Fig. 2, range 25), suggesting a total of 125km 6 7 km of post-Cretaceous, west-northwestern extension has separated them(Table 2). This offset is strengthened by cor-relations of additional contractile structuresexposed across the Death Valley extensionalsystem (Snow and Wernicke, 1989; Snow,

1992; Snow and Wernicke, 2000) and distinc-tive middle Miocene sedimentary depositsthat occur along the extensional path (Niemiet al., 2001). These include proximal con-glomeratic strata of the Eagle Mountain For-mation, which were derived from the north-eastern margin of the Hunter Mountainbatholith in the southern Cottonwood Moun-tains (Fig. 2, range 32). Recognition and cor-relation of this dismembered early extensionalbasin, in conjunction with stratigraphic con-straints from other Tertiary deposits in the re-gion, indicates that its fragmentation occurredmainly from 12 Ma to 2 Ma (Fig. 4). Thecorrelation of these deposits yields a displace-ment vector of 104 km 6 7 km orientedN678W between the Nopah–Resting SpringsRange (Fig. 2, range 27) and the CottonwoodMountains (Fig. 2, range 32).

To the ;170 km of displacement from theseconstraints, we add four additional estimatesto complete the reconstruction path. In theLake Mead system, 15 km of extension be-tween the Gold Butte area and the ColoradoPlateau (Fig. 2, range 23) (Brady et al., 2000)and a maximum of 8 km of extension betweenthe Spring Mountains (Fig. 2, range 25) andFrenchman Mountain (Fig. 2, range 24) (Wer-nicke et al., 1988) increases the total displace-ment of the Spring Mountains relative to theColorado Plateau to ;88 km. In the DeathValley system, an addition of 9 km of dis-placement in both the Panamint and OwensValleys increases the total displacement to;147 km between the Spring Mountains andthe Sierra Nevada.

The sum of all displacements along the pathis therefore 235 km 6 20 km (Table 2), whichrepresents a combination of areal dilation(crustal thinning) and plane strain (strike-slipfaulting). Approximately 80% of the elonga-tion is accommodated by vertical thinning and;20% by north-south contraction (Wernickeet al., 1988; Snow and Wernicke, 2000). Inaddition to this path, there are a number ofmore local offsets that were used to positionpolygons to the north and south, which areshown in Figure 4 and summarized in Table 2.

Southern Basin and Range–Rio GrandeRift

Extension in the southern Basin and Rangeis almost completely dominated by the for-mation of large-offset normal faults that formthe metamorphic core complexes (Coney,1980; Spencer and Reynolds, 1989; Dickin-son, 2002). The core complexes ring thesouthwestern margin of the Colorado Plateau(Fig. 2, ranges 37–44), and estimates of the



Figure 5. Map of the Mojave and Southern Basin and Range region showing distributionof strike-slip faults (bold lines), vertical axis rotation data (curved arrows), and extensionaloffsets (straight arrows). For strike-slip faults, reported slip amounts (black numbers) arecontrasted with model slip (bold blue numbers). For extension and rotation constraints,black numbers indicate horizontal displacement or amount of rotation, bold red numbersindicate age range of deformation. Red shaded area is the area of the model that undergoes24–18 Ma core complex extension in the Mojave region. WRT indicates measured dis-placement is ‘‘with respect to’’ the Colorado Plateau. Data from Ballard, 1990; Bassettand Kupfer, 1964; Dokka, 1983, 1989; Foster et al., 1993; John and Foster, 1993; Ham-ilton, 1987; Howard and Miller, 1992; Miller, 1980; Miller and Morton, 1980; Powell,1981; Richard et al., 1992; Richard, 1993; Richard and Dokka, 1992; Spencer and Reyn-olds, 1989; Spencer et al., 1995; Schermer et al., 1996; Walker et al., 1995.

total extension they represent are remarkablysystematic in magnitude, direction, and rate(Table 3). The timing of extension varies inage from 28 Ma to 14 Ma as the extensionmigrates from southeast to northwest. The mi-gration of extension has been related to a sim-ilar migration in volcanism. Both extensionand volcanism have been proposed to be a re-sult of the northwestward foundering of theFarallon plate (e.g., Humphreys, 1995; Dick-inson, 2002).

In a similar time frame (ca. 26 Ma), vol-caniclastic sediments deposited east of theColorado Plateau in the Rio Grand Rift (Fig.2, location 45) have been interpreted as rep-resenting the onset of extension (Chapin andCather, 1994). Ingersoll (2001) counters thatthe early sediments are broad volcaniclasticaprons that show no evidence of syndeposi-tional faulting. He places the initiation of rift-ing slightly later (ca. 21 Ma). Based on initi-ation of half-graben sedimentation and strataltilting, rapid extension occurred between 17

and 10 Ma (Ingersoll, 2001; Chapin and Cath-er, 1994). The total magnitude of extension issmall and ranges from 6 km in the northernpart of the rift to 17 km in the south, consis-tent with the 1.58 clockwise rotation of theColorado Plateau (Chapin and Cather, 1994;Russell and Snelson, 1994).

Extension within the Rio Grande rift is con-tiguous with the broad extended region farthersouth, east of the Sierra Madre Occidental (inChihuahua), the magnitude of which is poorlyunderstood (Dickinson, 2002). Generally, ex-tension in the Mexican Basin and Range ispartitioned both in time and space. Early corecomplex extension is documented in north-western Mexico (in Sonora), just west of theSierra Madre Occidental (Nourse et al., 1994;Gans, 1997) (Fig. 2). Palinspastic reconstruc-tions over small regions in Sonora suggest cu-mulative extension of 90%, mostly between26 and 20 Ma, and more modest extension(10%–15%) between 20 and 17 Ma (Gans,1997). Limited crustal extension is also doc-

umented east of the Sierra Madre Occidentalduring the same time period (Dickinson,2002). Major extension occurred in both Chi-huahua (Henry and Aranda-Gomez, 2000;Dickinson, 2002) and Sonora Mexico (e.g.,Stock and Hodges, 1989; Henry, 1989; Lee etal., 1996) from ca. 12 Ma to 6 Ma as a preludeto the opening of the Gulf of California at 6Ma (Oskin et al., 2001). During the 12 Ma to6 Ma interval, very small magnitude east-west‘‘Basin and Range’’ extension affected Ari-zona (Spencer and Reynolds, 1989; Spenceret al., 1995).

Mojave Region

Cenozoic deformation of the Mojave regionoccurred in two main stages. Deformation be-gan in the late Oligocene–early Miocene withthe formation of large-offset normal faults andassociated core complexes (Glazner et al.,1989; Dokka, 1989; Walker et al., 1990). Ex-tension in the Mojave region (Fig. 2, location41, and Fig. 5) may be linked to core complexextension in the southern Basin and Rangecorridor (Fig. 2, ranges 38 and 44) through adiffuse transfer zone that involves both rota-tion and strike-slip faulting (Bartley and Glaz-ner, 1991; Martin et al., 1993). The magnitudeof extension is determined through alignmentof pre-extensional markers that include faciestrends in Paleozoic strata, a unique gabbro-granite complex, and late Jurassic dikes, in-dicating a total of 40–70 km of offset (Glazneret al., 1989; Walker et al., 1990; Martin et al.,1993). Extension began in synchronism withthe eruption and emplacement of 24–23 Maigneous rocks (Walker et al., 1995) and iscapped by the flat-lying, 18.5 Ma PeachSprings Tuff (Glazner et al., 2002). The frac-tion of the Mojave Desert region that was af-fected by mid-Tertiary extension is controver-sial (e.g., Dokka, 1989; Glazner et al., 2002).Glazner et al. (2002) propose that only a smallregion north of Barstow (Fig. 2, location 41)was affected by the early extension, with thesouthern boundary of this extensional domainlinked to core complex extension to the south-east through diffuse right-lateral shear. Thenorthern boundary of the extensional domainis more problematic; however, regional kine-matic compatibility requires a northern trans-fer zone that links Mojave extension to similarage extension to the north or west. Rotationof the Tehachapi Mountains and/or extensionin the southern San Joaquin Valley may rep-resent the northern portion of this system(McWilliams and Li, 1985; Plescia and Cald-erone, 1986; Tennyson, 1989; Goodman and



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ND

RA

NG

ELA

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UD

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ge/fa

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Hor

izon

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lace

men

tof

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ock

(mod

elpo

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n)

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izon

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pone

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ata)

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ing

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ate

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atio

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oriz

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ntof

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tsl

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urat

ion)

Dire

ctio

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ion

Dat

aus

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umul

ativ

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spla

cem

ent

(6cu

mul

ativ

eer

ror)

Long

.(x

)La

t.(y

)

San

Pitc

h/G

unni

son

(1)

[346

]4

km4

km6

2;

18–0

Ma

0.22

km/m

.y.

E-W

Str

atig

raph

icse

para

tion

Hin

tze,

1973

4km

62

km2

111.

7887

939

.502

97C

anyo

n/Le

van

and

Fay

ette

segm

ents

,W

asat

chfa

ult

(2)

[358

]

5km

5km

62

km;

10–0

Ma

0.5

km/m

.y.

E-W

Hol

ocen

eve

rtic

alof

fset

rate

san

dM

ioce

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atio

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tes,

assu

me

;30

8di

p

Nei

mie

tal

.,20

04;

Mac

hette

etal

.,19

92;

Jack

son,

1991

;S

mith

and

Bru

hn,

1984

;

6km

63

km2

112.

1542

139

.560

62

Cric

ket

Ran

ge/S

evie

rD

eser

tD

etac

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00]

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40km

62

km;

18–0

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2.22

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al)

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ace

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gan

and

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elle

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96;

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etal

.,19

9546

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km2

112.

7558

239

.213

01

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0km

;19

–15

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.A

FT

cool

ing

ages

assu

min

ga

34-4

0de

gree

faul

tS

tock

liet

al.,

2001

22km

16-3

0km

15–0

Ma

1km

/m.y

.S

tock

liet

al.,

2001

Hou

seR

ange

/‘‘R

eflec

tion

F’’

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)[3

50]

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Ma

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Offs

etre

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Allm

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.,19

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639

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02

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59]

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mat

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;15

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AF

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992

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[366

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),22

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–18)

30km

63

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63

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(pau

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–18M

a)18

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km/m

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35–2

5M

a,2

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from

18-0

Ma,

3km

/m.y

.fr

om18

-14

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1.7

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from

14-0

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E-W

Map

rela

tions

stra

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phic

offs

et,

Ar/

Ar

cool

ing

ages

and

AF

Tda

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sts

10.5

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kmof

slip

betw

een

18-1

4M

a)

Gan

san

dM

iller

,19

83;

Bar

tley

and

Wer

nick

e,19

84;

Lee

1995

;M

iller

etal

.,19

99;

Lew

iset

al.,

1999

102

km6

5.5

km2

114.

1164

239

.435

17

Sch

ellC

reek

Ran

ge/S

prin

gV

alle

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(7)

[362

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11km

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-0

Ma

E-W

Map

rela

tions

,AF

T,

ZF

T,

Ar/

Ar

Bar

tley

and

Wer

nick

e,19

84;

Gan

set

al.,

1985

;Le

e,19

95;

Mill

eret

al.,1

999;

Lew

iset

al.,

1999

113

km6

6km

211

4.63

925

39.2

2082

But

teM

tns.

/Ega

nR

ange

low

-an

gle

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)16

km6

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,5

kmex

hum

atio

n35

–25

Ma

16–1

7M

aE

-WB

artle

yan

dW

erni

cke,

1984

;G

ans

etal

.,19

85;

Lee,

1995

;S

tock

li,19

99

129

km6

6km

211

4.91

863

39.0

7945

Ega

nR

ange

toS

hosh

one

Mou

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ns(9

–14)

45.6

km47

km6

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(26

excl

udin

gT

oiya

bera

nge)

16–0

Ma

26km

/16

m.y

./5ra

nges

E-W

Map

rela

tions

and

cros

sse

ctio

nre

stor

atio

n.S

mith

etal

.,19

9117

6km

611

.8km

Pin

eR

ange

/Gra

ntR

ange

and

Buc

kR

ange

faul

ts(9

)[3

48]

5km

6km

61.

5km

,;

5km

exhu

mat

ion

;15

km.3

25km

/m.y

.E

-W’’

Lund

etal

.,19

93;

Tay

lor

etal

.,19

892

115.

3773

240

.399

33

Dia

mon

dR

ange

/Pan

cake

Ran

ge/

Mah

ogan

yH

illsfa

ults

(10)

[360

]5

km5

kmof

26to

tal

unkn

own,

assu

med

;16

–0M

a.3

25km

/m.y

.E

-WM

apre

latio

nsan

dcr

oss

sect

ion

rest

orat

ion.

Sm

ithet

al.,

1991

211

5.82

060

39.8

3001

Sul

fur

Spr

ings

Ran

gefa

ults

(11)

5km

5km

of26

tota

las

sum

ed;

16–0

.325

km/m

.y.

E-W

’’S

mith

etal

.,19

91T

oqui

ma

Ran

ge/S

imps

onP

ark

Mou

ntai

nsfa

ult

(12)

[364

]5

km5

kmof

26to

tal

assu

med

;16

–0.3

25km

/m.y

.E

-W’’

Sm

ithet

al.,

1991

211

6.82

368

39.1

5694

Toi

yabe

Ran

gefa

ults

(13)

[368

]5

km(2

5–35

),16

km(0

–16)

21km

exte

nsio

n,;

5km

exhu

mat

ion

35–2

5M

a,16

–0M

a.5

km/m

.y.

(35-

25),

1km

/m.y

.(1

6-0)

E-W

’’S

mith

,19

92;

Sto

ckli,

1999

176

km6

11.8

km2

116.

8173

240

.337

06

Sho

shon

eM

ount

ain

faul

ts(1

4)[3

63]

4.6

km5

kmof

26to

tal

assu

med

;16

–0M

a.3

25km

/m.y

.N

64W

’’S

mith

etal

.,19

912

117.

3797

239

.471

25

Par

adis

eR

ange

faul

t(1

5)[3

51]

3.5

km3

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1as

sum

ed;

16–0

Ma

.188

km/m

.y.

N65

WP

arad

ixe,

C.

Alp

ine

and

Stil

lwat

erR

ange

sre

pres

ent

100

kmar

eath

atha

sge

ogra

phic

alex

tent

onm

ap

179

km6

11.8

km2

117.

5617

839

.321

98

C.

Alp

ine

Ran

gefa

ult

(16)

[349

]3

km3

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1as

sum

ed;

16–0

Ma

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km/m

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N65

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xten

ded

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know

nam

ount

182

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11.8

km2

117.

7081

439

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61

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ange

faul

t(1

7)[3

54]

1.5

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1as

sum

ed;

16–0

Ma

.188

km/m

.y.

N65

WU

nkno

wn/

best

estim

ate

185

km6

11.8

km2

117.

8555

740

.264

51

Gill

is/G

abbs

Val

ley

Ran

ge.

Gum

drop

hills

,In

dian

head

,B

ento

nsp

ring,

Pet

rified

Spr

ing

faul

ts.

(18)

[326

]

211

7.85

557

40.2

6451

youn

ger

than

25M

a6.

75km

/m.y

.(if

sinc

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Ma)

N14

WO

ffset

ofst

eep

beds

(Tria

ssic

age)

,gr

anite

intr

usio

nsan

dtu

ffs

Har

dym

anet

al.,

1984

203

km6

13.3

km2

118.

4691

538

.811

73

Nor

ther

nW

alke

rLa

nefa

ult

syst

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(0–6

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5-10

km/m

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(ifsi

nce

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etse

gmen

tsof

Eas

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oval

ley

Fau

lds

etal

.,20

03

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sak

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ult

syst

em(1

9)[3

54]

16km

11.7

66

1km

(13.

36

3km

)15

–0M

aE

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ross

sect

ion

rest

orat

ion

plus

unro

ofing

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Sur

ples

s,19

99;

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ckli

etal

.,20

0221

5km

613

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211

8.88

407

38.6

6236

10.5

km8.

71km

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5M

a4.

3km

/m.y

.E

-Wfr

omva

lley

betw

een

Sin

gats

e’’

2km

2.1

km9–

7M

a1.

05km

/m.y

.E

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dW

assa

kra

nges

’’3.

4km

0.5

km(0

62)

,2.

56

27–

0M

a.3

km/m

.y.

E-W

’’

Sin

gats

eR

ange

faul

tsy

stem

(20)

[365

]15

.66

km13

62

15to

0M

aO

ffset

volc

anic

and

sedi

men

tary

rock

s,A

r/A

ris

otop

eag

es

Dill

esan

dG

ans,

1995

228

km6

13.8

km2

119.

2535

738

.959

20

7.66

kmM

ain

phas

e7.

2614

–12

Ma

3.63

km/m

.y.

E-W

’’4.

4km

1.7

km11

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a.5

6km

/m.y

.E

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3.6

km4.

1km

7–0

Ma

.58

km/m

.y.

E-W

’’B

ucks

kin

Mtn

s./P

ine

Nut

Val

ley/

Pin

eN

utR

ange

Fau

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1)[3

52]

5km

76

2,2–

3km

ofex

hum

atio

n10

–0M

a.7

km/m

.y.

E-W

Offs

etfr

omm

appe

dun

its;

timin

g(1

0-5

Ma)

from

Sur

ples

s

Hud

son

and

Orie

l,19

79;

Sto

ckli,

1999

231

km6

14km

211

9.45

846

38.7

1853

Tot

alex

tens

ion

236

km23

56

14km

N78

8W

Not

e:Lo

ng.—

long

itude

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t.—la

titud

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R—

Can

yon

Ran

ge;

AF

T—

Apa

tite

Fis

sion

Tra

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olin

gag

e.N

umbe

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pare

nthe

ses

refe

rto

spec

ific

rang

esid

entifi

edon

Fig

.2;

num

bers

inbr

acke

tsre

fer

toth

eR

AN

GE

pID

num

ber

for

indi

vidu

alra

nges

inth

eA

rcG

ISsh

ape

files

and

the

Mov

emen

tT

able

(Arc

GIS

files

,M

ovem

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able

[see

foot

note

1]).

The

cum

ulat

ive

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rre

port

edin

colu

mn

9eq

uals

the

squa

rero

otof

the

sum

ofth

esq

uare

sfo

rin

divi

dual

vect

ors.


N. MCQUARRIE and B.P. WERNICKET

AB

LE2.

DA

TA

US

ED

FO

RR

ES

TO

RIN

GE

XT

EN

SIO

NIN

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n)

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Dat

aus

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ence

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spla

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mul

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ror)

Long

.(x

)La

t.(y

)

Mor

mon

Mou

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ea/

Mor

mon

Pea

k,T

ule

Spr

ings

and

Cas

tleC

liff

deta

chm

ents

(22)

[73]

68km

546

1016

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Ma

13.5

km/m

.y.

S60

EC

ross

sect

ion

reco

nstr

uctio

nth

roug

hB

eave

rD

am/T

ule

Spr

ings

and

Mor

mon

Pea

kde

tach

men

tsys

tem

s

Axe

net

al.,

1990

54km

610

km2

114.

2455

237

.094

63

Gol

dB

utte

/Sou

thV

irgin

Mou

ntai

nsde

tach

men

t(23

)[5

7]

18km

156

5;

17–1

5M

a7.

5km

/m.y

.E

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ross

sect

ion

reco

nstr

uctio

n,A

FT

cool

ing

ages

,ov

erla

ppin

g15

Ma

basa

lt

Wer

nick

eet

al.,

1988

;B

rady

etal

.,20

00;

Fitz

gera

ldet

al.,

1991

15km

65

km2

114.

2092

036

.387

48

Fre

nchm

anM

ount

ain/

Lake

Mea

dfa

ult

syst

em(2

4)[4

7]60

km60

min

90m

ax65

615

16–1

2M

a16

.25

km/m

.y.

N75

EM

egab

recc

iafr

omG

old

But

te,

pinc

hout

ofM

zfo

rmat

ions

,Virg

inM

ount

ains

deta

chm

ents

yste

m

Sno

wan

dW

erni

cke,

2000

;D

uebe

ndor

fer

and

Bla

ck,

1992

;D

uebe

ndor

fer

etal

.,19

98;

Wer

nick

eet

al.,

1988

80km

616

km2

114.

9699

936

.203

12

Spr

ing

Mou

ntai

ns/L

asV

egas

faul

tsy

stem

(25)

[53]

8km

8km

68

15–1

1M

aN

75E

Unk

now

nam

ount

ofex

tens

ion

betw

een

Spr

ing

Mou

ntai

nan

dF

renc

hman

Mtn

.

Wer

nick

eet

al.,

1988

88km

618

km2

115.

6091

236

.066

31

Las

Veg

assh

ear

zone

Und

eter

min

ed47

67

km15

–11

Ma

11.7

5km

/m.y

.A

lignm

ent

ofG

ass

Pea

kth

rust

(She

epR

ange

)w

ithW

heel

erP

ass

thru

st(S

prin

gM

t.).

Sno

wan

dW

erni

cke,

2000

;B

urch

fiele

tal

.,19

87;

Wer

nick

eet

al.,

1988

She

epR

ange

,P

intw

ater

Ran

ge,

Spo

tted

Ran

gede

tach

men

t(26

)[5

9,61

,64

]

23km

206

5km

13M

a–?

(9M

a)3.

67km

/m.y

.N

63W

Ext

ensi

onas

soci

ated

with

the

She

epR

ange

deta

chm

ent,

exte

nsio

nam

ount

base

don

cros

sse

ctio

nre

stor

atio

n

Gut

h,19

89;

Sno

wan

dW

erni

cke,

2000

;S

now

,19

9274

km6

11km

211

4.91

820

36.6

3221

Nop

ahR

ange

,R

estin

gS

prin

gR

ange

,S

prin

gM

tns.

deta

chm

ent(

27)

[50]

26km

;25

63

km14

–9M

a5

km/m

.y.

N63

WA

lignm

ent

ofth

etr

ace

ofth

eW

heel

erP

ass

thru

sts

with

resp

ect

toot

her

thru

sts

inth

esy

stem

Wer

mic

keet

al.,

1988

,S

now

and

Wer

nick

e,20

0011

3km

618

km2

116.

1889

236

.271

85

Cot

tonw

ood,

Pan

amin

t,B

lack

Mou

ntai

ns/A

mar

gosa

,cen

tral

Dea

thV

alle

y,E

mig

rant

deta

chm

ents

(28,

30,

32)

[54]

102

km10

4km

67

11–2

(?)

Ma

11.5

km/m

.y.

N67

WT

heor

igin

alex

tent

ofE

agle

Mou

ntai

nF

orm

atio

nm

ust

have

been

with

in20

kmof

sour

cear

eain

sout

hern

Cot

tonw

oods

.

Nei

mie

tal

.,20

0121

7km

619

km2

117.

1595

236

.203

16

Res

ting

Spr

ings

,N

opah

Ran

ges

and

Bla

ck,

Pan

amin

tM

ount

ains

/G

rape

vine

,A

mar

gosa

,ce

ntra

lDea

thV

alle

yar

eade

tach

men

ts(2

7,28

,30

)

105

km10

06

79–

5M

a22

.5km

/m.y

.N

78W

Will

owS

prin

gpl

uton

intr

uded

(10-

12km

)at

11.6

cool

edra

pidl

y(6

-7

Ma)

and

appe

ars

inbo

ulde

rsat

;5

Ma.

(Am

argo

sach

aos)

.A

lignm

ent

ofth

rust

-bel

tst

ruct

ures

Wer

nick

eet

al.,

1988

;S

now

and

Wer

nick

e,20

00;

Hol

met

al.,

1992

;H

olm

and

Dok

ka,

1993

;S

now

,19

92

Kin

gsto

nR

ange

/Kin

gsto

nR

ange

deta

chm

ent(

29)

[38]

6km

6km

13.1

–12

Ma

6km

/m.y

.E

-WD

epos

ition

inth

eS

hado

wV

alle

yB

asin

Fow

ler

and

Cal

zia,

1999

211

5.88

365

35.6

8015

Sou

ther

nB

lack

Mou

ntai

ns/

Kin

gsto

nR

ange

,A

mar

gosa

deta

chm

ents

(30)

[52]

25km

256

3km

12–8

Ma

6.25

km/m

.y.

E-W

Gra

nite

meg

abre

ccia

s(in

the

grea

ter

Am

argo

saba

sin)

poss

ibly

deriv

edfr

oma

disp

lace

dpo

rtio

nof

Kin

gsto

nR

ange

plut

on(w

est

ofba

sin)

.

Sno

wan

dW

erni

cke,

2000

211

6.59

671

36.0

3965

Fun

eral

,G

rape

vine

Mou

ntai

ns/

Poi

ntof

Roc

ksde

tach

men

t(3

1)[6

0]

Und

eter

min

ed;

10km

14–1

0M

a2.

5km

/m.y

.N

45E

Ope

ning

ofth

eex

tens

iona

lBul

lfrog

Bas

inC

emen

etal

.,19

85;

Sno

wan

dLu

x,19

992

116.

8703

036

.687

89

Gra

pevi

neM

ount

ains

,Bar

eM

ount

ain/

Bul

lfrog

deta

chm

ents

(31)

[72,

58]

60km

526

214

–7M

a7.

43km

/m.y

.S

68E

Cor

dille

rafo

ld-t

hrus

tbel

tre

cons

truc

tions

Sno

wan

dW

erni

cke,

2000

,19

892

116.

6792

436

.875

79

Gra

pevi

neM

ount

ains

,Fun

eral

Mou

ntai

ns/B

ound

ary

Can

yon

deta

chm

ent(

31)

[72]

32km

356

2km

9–5

Ma

8.75

km/m

.y.

S37

EC

ordi

llera

fold

-thr

ustb

elt

reco

nstr

uctio

ns,A

FT

,Z

FT

and

sphe

neF

Tco

olin

gag

es

Sno

wan

dW

erni

cke,

2000

,19

89;

Sno

w,

1992

,H

oisc

han

dS

imps

on,

1993

;H

olm

and

Dok

ka,

1991

211

7.21

776

37.1

2056

Nor

ther

nD

eath

Val

ley

206

105–

0M

a2-

6km

/m.y

.E

-WO

ffset

thru

stfa

ult

and

Qua

tern

ary

mar

kers

Reh

eis

1993

,R

ehei

san

dS

awye

r,19

97C

otto

nwoo

dM

ount

ains

/E

mig

rant

faul

tsy

stem

(32)

[70]

22km

226

3km

6–3.

2M

a5.

5km

/m.y

.S

45E

Cor

rela

tion

ofW

hite

Top

back

fold

inC

otto

nwoo

d,F

uner

alM

ount

ains

and

Spe

cter

Ran

ge

Wer

nick

eet

al.,

1988

;S

now

,19

92;

Sno

wan

dLu

x,19

99;

Sno

wan

dW

erni

cke,

2000

211

7.57

841

36.8

7160

Dar

win

Pla

teau

,In

yoM

ount

ains

/Hun

ter

faul

t(3

3)[5

1,66

]

9km

96

14.

8–0.

6M

a2.

25km

/m.y

.S

55E

Cor

rela

tion

ofS

alin

eR

ange

volc

anic

sB

urch

fiele

tal

.,19

8722

6km

619

km2

117.

6613

236

.174

92

Sie

rra

Nev

ada/

Ow

ens

Val

ley

faul

tsy

stem

(34)

[65]

;9

km9

66

0–4

Ma

2.25

km/m

.y.

S60

EE

stim

ate

of15

%6

10%

exte

nsio

nW

erni

cke

etal

.,19

8823

5km

620

km2

119.

8016

337

.885

03

Tot

alex

tens

ion

232

km23

56

20km

N78

8W

Not

e:Lo

ng.—

long

itude

;La

t.—la

titud

e;A

FT

—A

patit

eF

issi

onT

rack

cool

ing

age;

ZF

T—

Zirc

onfis

sion

trac

kag

e;F

T—

Fis

sion

Tra

ck.

Num

bers

inpa

rent

hese

sre

fer

tosp

ecifi

cra

nges

iden

tified

onF

ig.

2;nu

mbe

rsin

brac

kets

refe

rto

the

RA

NG

EpI

Dnu

mbe

rfo

rin

divi

dual

rang

esin

the

Arc

GIS

shap

efil

esan

dth

eM

ovem

entT

able

(Arc

GIS

files

,M

ovem

ent

Tab

le[

see

foot

note

1]).

The

cum

ulat

ive

erro

rre

port

edin

colu

mn

9eq

uals

the

squa

rero

otof

the

sum

ofth

esq

uare

sfo

rin

divi

dual

vect

ors.


ANIMATED TECTONIC RECONSTRUCTIONT

AB

LE3.

DA

TA

US

ED

FO

RR

ES

TO

RIN

GE

XT

EN

SIO

NIN

SO

UT

HE

RN

BA

SIN

AN

DR

AN

GE

Ran

ge/fa

ult

Hor

izon

tal

disp

lace

men

tof

rang

ebl

ock

(mod

elpo

lygo

n)

Hor

izon

tal

com

pone

ntof

faul

tsl

ip(d

ata)

Tim

ing

ofsl

ipR

ate

ofde

form

atio

n(h

oriz

onta

lcom

pone

ntof

faul

tsl

ip/d

urat

ion)

Dire

ctio

nof

mot

ion

Dat

aus

edR

efer

ence

sLo

ng.

(x)

Lat.

(y)

McC

ullo

ugh

Ran

geto

Col

orad

oP

late

au(3

5)[3

7]80

km50

-80

km14

–16

Ma

(24)

8km

/m.y

.S

75W

Res

tora

tion

ofst

rike

slip

faul

tof

fset

s,til

ted

volc

anic

rock

s,po

rphy

ryco

pper

empl

acem

ent

dept

hs

Spe

ncer

and

Rey

nold

s,19

89;

John

and

Fos

ter,

1993

211

5.34

595

35.1

7415

Bla

ckM

ount

ains

(36)

[46]

36km

(tot

al)

.25

km15

–13.

4M

a2.

5km

/m.y

.N

70E

Tilt

edvo

lcan

icro

cks.

Fos

ter

etal

.,19

93;

Spe

ncer

etal

.,19

95;

Spe

ncer

and

Rey

nold

s,19

89

211

4.49

030

35.4

7688

Sac

ram

ento

,Che

meh

uevi

Eld

orad

oM

ount

ains

(37)

[44]

36km

.25

–30

km21

–15

Ma

5km

/m.y

.S

60W

Ar/

Ar,

AF

Tco

olin

gag

esJo

hnan

dF

oste

r,19

932

114.

7685

435

.311

17

Buc

kski

n,R

awhi

deM

ount

ains

(38)

[629

]66

km66

km6

8km

27–1

3M

a4.

7km

/m.y

.S

57W

Tim

ing

indi

cate

dby

tilte

dvo

lcan

icst

rata

,m

agni

tude

dete

rmin

edby

offs

etne

cess

ary

toex

pose

low

erpl

ate

Sco

ttet

al.,

1998

;F

oste

ret

al.,

1993

;S

penc

eret

al.,

1995

;S

penc

eran

dR

eyno

lds,

1991

211

3.74

331

34.0

9275

Cat

alin

a,R

inco

nM

ount

ains

(39)

[648

]28

km20

–30

km,

coul

dbe

upto

40km

27–2

0M

a4

km/m

.y.

S60

WC

orre

latio

nof

Pre

cam

bria

ngr

anite

and

pre-

mid

Ter

tiary

thru

stin

gD

avy

etal

.19

89;

Dic

kins

on,

1991

;F

ayon

etal

.,20

002

110.

7158

432

.350

01

Har

quah

ala,

Har

cuva

rM

ount

ains

(40)

[657

]66

km67

km6

17km

26–1

4M

a5.

6km

/m.y

.S

57W

Dis

plac

edbr

ecci

as(5

5km

)pl

usad

ditio

nale

xten

sion

invo

lcan

ican

dP

reca

mbr

ian

rock

s(1

26

7)

Ric

hard

etal

.,19

90;

Spe

ncer

and

Rey

nold

s,19

91.

211

3.51

995

33.8

6443

Pin

alen

oM

ount

ains

(41)

[647

]22

km20

–30?

km29

–19

Ma

2.5

km/m

.y.

S60

WA

r/A

rco

olin

gag

es,

appr

oxim

ate

amou

ntof

disp

lace

men

tne

cess

ary

toex

pose

low

erpl

ate

Long

etal

.,19

952

110.

0116

332

.772

88

Sou

thM

ount

ain

(43)

[653

,654

]50

km25

-19

Ma

S60

WR

eyno

lds,

1985

211

1.60

311

33.1

3175

Whi

pple

Mou

ntai

n(4

4)[6

65]

63km

71km

619

km22

–16

Ma

11.8

km/m

.y.

S57

WO

ffset

ofdi

kesw

arm

,til

ted

sedi

men

tary

stra

taD

avis

and

List

er,

1988

;S

penc

eran

dR

eyno

lds,

1991

211

4.10

627

34.3

1624

Rio

Gra

ndex

tens

ion

(45)

7km

6km

12–1

8M

a.8

75km

/m.y

.38

8Npa

linsp

astic

rest

orat

ion

ofse

ism

icco

ntro

lled

cros

sse

ctio

n,an

dgr

owth

stra

tain

basi

n

Cha

pin

and

Cat

her,

1994

;In

gers

oll,

2001

;R

usse

llan

dS

nels

on,

1994

13km

10km

12–1

8M

a1.

625

km/m

.y.

368N

Cha

pin

and

Cat

her,

1994

;In

gers

oll,

2001

;R

usse

llan

dS

nels

on,

1994

17km

17km

12–1

8M

a2

km/m

.y.

358N

Cha

pin

and

Cat

her,

1994

;In

gers

oll,

2001

;R

usse

llan

dS

nels

on,

1994

Not

e:Lo

ng.—

long

itude

;La

t.—la

titud

e;A

FT

—A

patit

eF

issi

onT

rack

cool

ing

age.

Num

bers

inpa

rent

hese

sre

fer

tosp

ecifi

cra

nges

iden

tified

onF

ig.

2;nu

mbe

rsin

brac

kets

refe

rto

the

RA

NG

EpI

Dnu

mbe

rfo

rin

divi

dual

rang

esin

the

Arc

GIS

shap

efil

esan

dth

eM

ovem

ent

Tab

le(A

rcG

ISfil

es,

Mov

emen

tT

able

[see

foot

note

1]).

Malin, 1992; Walker et al., 1995; Glazner etal., 2002).

Following this early phase of extensionaldeformation, a system of right- and left-lateralstrike-slip faults similar to those active todaywas established, with right-lateral shear alonga series of northwest-striking faults predomi-nant (Fig. 5). The total accumulated shearacross the Mojave, as documented by fieldstudies, is 53 km 6 6 km (Table 4). The tim-ing of right-lateral shear is not well con-strained. Motion on the faults is inferred to bepost–10 Ma based on strain compatibility withdeformation directly north and south (Tables2 and 5).

Vertical Axis Rotations East of the SanAndreas Fault

There are two zones of vertical-axis rotationeast of the San Andreas fault: the EasternTransverse Ranges located immediately southof the Mojave block and the northeastern Mo-jave rotational block (Carter et al., 1987;Schermer et al., 1996; Dickinson, 1996) (Fig.5 and Table 4).

The Eastern Transverse Ranges include aseries of structural panels separated by east-west–oriented, left-lateral faults (Dickinson,1996). Paleomagnetic studies show that 10 62 Ma rocks within this zone record the entire458 rotation (Carter et al., 1987), while 4.5 Mavolcanic rocks are unrotated (Richard, 1993).These constraints imply that all of the rotationand most of the right-lateral strike-slip motionin the Mojave region immediately to the northare ca. 10 Ma and younger.

The northeastern corner of the Mojave re-gion is another area of pronounced clockwiserotation. Schermer et al. (1996) proposed thatthe northeastern Mojave underwent 238 of ro-tation accompanied by 5 km of left-lateral slipon faults within the rotating region and 158 of‘‘rigid body’’ rotation. Total right-lateral shearpredicted by this model is 33 km.

San Andreas System and Areas to theWest

Deformation west of the San Andreas faultis defined by four first-order constraints (Fig.6 and Table 6). The first is motion on the SanAndreas fault itself, which is tightly con-strained in central California at 315 km 6 10km by restoring the Pinnacles volcanics westof the fault to the Neenach volcanics to theeast of it (Matthews, 1976; Graham et al.,1989; Dickinson, 1996). The offset volcanicswere extruded from 22 Ma to 24 Ma, but ten-tatively correlative late Miocene strata (7–8


N. MCQUARRIE and B.P. WERNICKET

AB

LE4.

DA

TA

US

ED

FO

RR

ES

TO

RIN

GS

TR

IKE

-SLI

PD

ISP

LAC

EM

EN

TS

INT

HE

MO

JAV

ER

EG

ION

Fau

ltH

oriz

onta

ldis

plac

emen

tof

rang

ebl

ock

(mod

elpo

lygo

n)H

oriz

onta

lcom

pone

ntof

faul

tsl

ip(d

ata)

Tim

ing

ofsl

ipD

ata

used

(offs

etfe

atur

es)

Ref

eren

ces

Cum

ulat

ive

disp

lace

men

tof

right

-late

ralf

ault

slip

data

(6cu

mul

ativ

eer

ror)

Cen

tral

Moj

ave

(41)

63km

40–5

0km

24-1

8M

aO

ffset

feat

ures

that

incl

ude

Jura

ssic

dike

s,in

trus

ive

rock

s,an

dsh

elf

tooc

ean

faci

estr

ansi

tion

Gla

zner

etal

.,19

89;

Mar

tinet

al.,

1993

;F

letc

her

etal

.,19

95;

Inge

rsol

let

al.,

1996

Azt

ecM

ines

Was

hfa

ult

8km

8km

LLpo

stlo

wer

Mio

cene

Intr

usiv

eco

ntac

tbe

twee

nS

anG

abrie

lter

rane

and

Cre

tace

ous

plut

on

Pow

ell,

1981

Blu

eC

utfa

ult

4km

6-9–

9km

Ant

iform

ingn

eiss

icfo

liatio

nH

ope,

1966

Bul

lion/

Rod

man

/Pis

gah

faul

t13

km6.

4–14

.4km

RL

Kan

esp

rings

faul

tD

okka

,19

8310

.4km

64

kmC

hiria

sco

faul

t7–

16km

11km

LLD

acite

dike

,an

dst

eepl

ydi

ppin

gR

edC

loud

thru

stfa

ult

Pow

ell,

1981

Chu

ckw

alla

Val

ley

basi

n31

km(R

L)gr

avity

low

Gra

vity

data

indi

cate

com

plex

basi

nst

ruct

ure

Rot

stei

net

al.,

1976

;R

icha

rd,

1993

Cib

ola

faul

t7

km7

kmR

LW

est

dipp

ing

norm

alfa

ults

,an

dea

stdi

ppin

gco

ntac

tbe

twee

nla

vas

Ric

hard

etal

.,19

92

For

dLa

keN

orth

basi

n5

km3.

5km

RL

Bas

eof

McC

oyM

ount

ains

form

atio

nS

tone

and

Pel

ka,

1989

Indi

anW

ash

Bas

in7

km7

kmR

LS

trat

igra

phic

sepa

ratio

nR

icha

rd,

1993

Iron

Mou

ntai

nsfa

ult

5km

5.5

kmR

LR

ock

units

(uns

peci

fied)

How

ard

and

Mill

er,

1992

Lagu

nafa

ult

syst

em36

km2

kmR

LS

lipes

timat

edby

estim

atin

gex

tens

ion

nece

ssar

yfo

r20

8di

pin

cong

lom

erat

e

Ric

hard

,19

93

Mam

mot

hW

ash

faul

t;

12km

;9

kmLL

Inte

rsec

tion

ofgr

eens

chis

tw

ithC

hoco

late

Mou

ntai

nT

hrus

tD

illon

,19

75

Mar

iafa

ult

4.5

kmR

LT

hrus

tfa

ults

and

sync

line

Ham

ilton

,19

87;

Bal

lard

,19

90M

esqu

iteLa

kefa

ult

3.5

kmR

LF

olds

inP

leis

toce

nese

dim

ents

Bas

sett

and

Kup

fer,

1964

Pac

kard

Wel

lfau

lt16

km16

kmR

LM

esoz

oic

rock

san

dst

ruct

ures

Pow

ell,

1981

;R

icha

rdan

dD

okka

,19

92P

into

Mou

ntai

nfa

ult

not

avai

labl

e18

–22

kmLL

Intr

usiv

eco

ntac

tsH

ope,

1966

;D

ibbl

ee,

1982

Sal

ton

Cre

ekfa

ult

8km

8km

LLC

orre

latio

nw

ithA

ztec

min

esfa

ult

Pow

ell,

1981

She

epH

ole,

Dry

Lake

sfa

ult

31km

23km

RL/

11km

RL

toea

rlyP

leis

toce

neP

hoto

inte

rpre

tatio

nP

owel

l,19

81;

How

ard

and

Mill

er,

1992

Val

ley

Mou

ntai

nfa

ult

21km

6.5–

14.4

kmR

LD

okka

,19

83;

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Ma) are apparently offset 255 km (Graham etal., 1989; Dickinson, 1996).

The second constraint is the ;1108 clock-wise rotation of major fault-bounded blocks inthe western Transverse Ranges (Hornafius etal., 1986; Luyendyk, 1991). Because of thelength and structural integrity of these blocks(in particular, the Santa Ynez Mountains), thisrotation requires a coast-parallel displacementof ;270 km (Hornafius et al., 1986).

The shear and rotation of these blocks areconfirmed by the third major constraint, re-construction of now-scattered outcrops of thedistinctive Eocene Poway Group. Exposuresalong the Channel Islands were rifted awayfrom counterparts in southernmost California,which are in turn offset from their source areain northern Sonora, Mexico, by the southernSan Andreas fault system (Abbott and Smith,1989). Rifting and rotation of the westernTransverse Ranges away from the PeninsularRanges formed the strongly attenuated crustof the Continental Borderlands on their trail-ing edge. The magnitude of this extension isproposed to be ;250 km based on seismicreflection data delineating the geometry of ex-tensional fault systems and correlation of‘‘mega key beds’’ or lithotectonic belts (fore-arc basin sediment, Franciscan subductioncomplex) (Crouch and Suppe, 1993; Bohan-non and Geist, 1998).

The final first-order constraint is the open-ing of the Gulf of California. Although offsetof the Poway Group suggests roughly 250 kmof displacement, recognition of correlative py-roclastic flows on Isla Tiburon and near Puer-tecitos on the Baja Peninsula dated at 12.6 Maand 6.3 Ma constrains the full transfer of BajaCalifornia to the Pacific plate to have occurredno earlier than ca. 6 Ma, with 255 km 6 10km of displacement along the plate boundarysince then (Oskin et al., 2001). Including ad-ditional deformation of the adjacent continen-tal margins increases the magnitude of dis-placement to as much as 276 km 6 10 km(Oskin and Stock, 2003).

WESTERN NORTH AMERICAANIMATION

The western North America animation (An-imation 1) combines 13 individual paleogeo-graphic maps (Figs. 7–9) (Appendix 1, paleo-geographic maps [see footnote 1])2 generatedby ArcGIS into a digital animation illustratinga model of how extension and right lateralshear evolved in the region. The color scheme

2If you are reading this offline, please visitwww.gsajournals.org to view Animation 1.



Figure 6. A: First-order constraints for displacement along the San Andreas fault andassociated displacements to the west. Arrows indicate approximate magnitude and direc-tion of individual relative displacements between polygons. Black numbers indicate hor-izontal displacement amount, bold red numbers indicate age range of displacement. Stip-pled areas labeled EPG show distribution of Eocene Poway Group and equivalents.Stippled area labeled SEPG marks the location of the source area for the Eocene PowayGroup. Triangle pattern (Gulf of California), and stars (central California) show distri-bution of correlative volcanic units offset by the San Andreas–Gulf of California riftsystem. MTJ is modern location of the Mendocino triple junction. Data from Abbott andSmith, 1989; Bohannon and Geist, 1998; Crouch and Suppe, 1993; Dickinson and Wer-nicke, 1997; Dickinson, 1996; Graham et al., 1989; Hornafius et al., 1986; Luyendyk, 1991;Matthews, 1979; Oskin et al., 2001. B: Successive locations of the eastern edge of Pacificplate oceanic lithosphere relative to stable North America. The thick colored lines rep-resent minimum extent of oceanic lithosphere at the times shown (from Atwater and Stock,1998). These positions constrain the maximum westward extent of continental NorthAmerica through time.

for the animation includes yellow, orange, andred polygons on a white background. Thepolygon shape reflects the modern bedrock-alluvium contact, fault-bounded crustal blocksor the physiographic boundaries of large, in-tact crustal blocks. Yellow polygons indicateareas where there are no data for how the re-gion is deforming. Orange polygons (ranges)are ranges whose motion is directly con-strained by kinematic data. These polygonsturn red during the time period of motion (i.e.,Baja California turns red from 6 to 0 Ma as itseparates from North America and movesnorthward on the Pacific Plate). A notable ex-ception to this is the Colorado Plateau–Rio

Grand rift area. Neither the Colorado Plateau,nor the Rio Grande rift turn red during rota-tion and extension even though there are datathat describe this deformation (Table 5). Thespace created (additional white space betweenthe colored polygons) as the movie progressesin time indicate areas of extension. The re-moval of white space (as polygons move clos-er together) indicates areas of compression.The thick blue line on the left of the animationrepresents successive locations of the easternedge of Pacific plate oceanic lithosphere rel-ative to stable North America at the time pe-riod annotated on the upper left edge of theline (from Atwater and Stock, 1998). The po-

sition of this line constrains the maximumwestward extent of continental North Americaat the time indicated because it shows the min-imum east limit of extant oceanic crust. De-tails of the reconstruction can be seen by mov-ing the slider bar on the animation. To moveback and forth over a narrow window of time,just hold the mouse key down over the trian-gle on the slider bar and move it back andforth over the time window of interest.

DISCUSSION

The exercise of developing a self-consistent,strain-compatible model has raised a numberof issues that are difficult to resolve satisfac-torily in the reconstruction and require furtherinvestigation. The most apparent (amongmany!) are (1) the need for middle to lateMiocene right-lateral shear in the eastern Mo-jave region to make room for the northerlymotion of the Sierra Nevada determined fromthe central and northern Basin and Range re-construction paths; (2) the need for largeamounts of relatively young extension innorthern Mexico both east and west of the Si-erra Madre Occidental to reconcile core com-plex extension in Arizona and the late Miocene–Pliocene opening of the Gulf of California; (3)the apparent rotational history of the SierraNevada–Great Valley block; and (4) generallylarge amounts of Miocene-Pliocene shorteningand extension in the Transverse Ranges, CoastRanges, and Borderlands provinces, whicharise from the need to reconcile San Andreasoffset with the position of oceanic crust off-shore, differences in the age of extensionnorth and south of the Garlock fault, and largeclockwise rotation of the Santa Ynez Moun-tains block (Animation 1).

Eastern Mojave Region

The eastern California shear zone–WalkerLane belt is an ;120-km-wide zone of right-lateral, intraplate shear east of the Sierra Ne-vada and San Andreas fault. Geodetically thisshear zone accommodates up to 25% of thePacific–North America relative plate motion(Bennett et al., 2003; McClusky et al., 2001;Miller et al., 2001; Sauber et al., 1994). Geo-logic estimates of displacements vary alongthe north-south extent of the eastern Californiashear zone. Proposed net displacement alongthe eastern California shear zone (oriented;N208W) varies from 65 km in the Mojaveregion (Dokka and Travis, 1990) to 133 km inthe central Basin and Range (Snow and Wer-nicke, 2000; Wernicke et al., 1988). In thenorthern Walker Lane region, shear estimates



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range from 20 km to 54 km (Faulds et al.,2005; Hardyman et al., 1984), plus an addi-tional component of northwest-directed exten-sion due to a change in extension direction inthe northern Basin and Range from east-westin the east to northwest-southeast in the west.

One of the goals of this study was to de-velop a kinematically consistent model of theeastern California shear zone that fits withinthe errors provided by both local and regionalstudies. We found 100 km 6 10 km right-lateral shear oriented N258W was compatiblewith data in both the northern and central Ba-sin and Range (Animation 1). In the Mojaveregion of the eastern California shear zone,however, available data suggest no more than53 km 6 6 km of right-lateral shear orientedN258W, about half of what is required to thenorth. Kinematic compatibility with the mag-nitude of deformation north of the Garlockfault requires ;100 km of right-lateral shearthough the Mojave region, with the majorityof additional shear located on the eastern edgeof the shear zone during its early (12–6 Ma)history (Figs. 5,7,8, Animation 1). The 27 kmand 45 km of right-lateral offset along theBristol Mountains–Granite Mountain andsouthern Death Valley fault zones is signifi-cantly greater than previous estimates (0–10km and 20 km, respectively), but solid pierc-ing points that limit the net offset are scarceand debatable (Howard and Miller, 1992;Dokka and Travis, 1990; Davis, 1977). The;30 km of displacement along the easternedge of the Mojave must be transferred south-ward along the Sheep Hole fault to the LagunaFault system of Richard (1993). The 36 km ofmodel offset is significantly greater than the 2km of right-lateral offset proposed by Richard(1993) (Table 4, Fig. 5). Additional faults withsignificantly greater offsets than that docu-mented by geology are the 11–13 km modeloffsets on the Camp Rock, Gravel Hills, andHarper Lake fault systems, where current es-timates suggest no more than 3 km of offseton any of these faults (Dibblee, 1964; Oskinand Iriondo, 2004; M. Strane, 2005, personalcommun.). The difference between the modeland data requires that the slip discrepancymust be taken up on other faults (most likelyto the east) in the Mojave shear system. Al-though the details concerning both timing anddistribution of shear within the eastern Cali-fornia shear zone will continue to evolve withtime, the strength of the central Basin andRange offsets combined with kinematic com-patibility constraints require reevaluation ofgeologic evidence for total magnitude of right-lateral shear through the Mojave. Therefore,we have modeled many of the faults in the



Figure 7. Reconstructed paleogeographic maps (from 0–6 Ma) used in the reconstruction. The color scheme is the same as that for theanimation, yellow polygons on a white background. Yellow polygons indicate areas where there are no data for how the region isdeforming. Polygons (ranges) that have data associated with their motion are orange when associated faulting is inactive and red duringfault activity. Panels represent different time slices: (a) 0 Ma, (b) 2 Ma, (c) 4 Ma, and (d) 6 Ma.



Figure 8. Reconstructed paleogeographic maps (from 8 to 14 Ma) used in the reconstruction. The color scheme is the same as Figure7. Panels represent different time slices: (a) 8 Ma, (b) 10 Ma, (c) 12 Ma, and (d) 14 Ma.



Figure 9. Reconstructed paleogeographic maps (from 16 to 36 Ma) used in the reconstruction. The color scheme is the same as Figure7. Panels represent different time slices: (a) 16 Ma, (b) 18 Ma, (c) 24 Ma, (d) 30 Ma, and (e) 36 Ma.



Figure 9. (continued).

Mojave with greater net offset than suggestedby offset markers. From the model slipamounts shown on Figure 5, we obtain 100km of right-lateral shear oriented N258Wsince 12 Ma, at a long-term rate of 8.3 mm/yr 6 1 mm/yr. We suggest that the discrep-ancy may be due to penetrative shear in thelargely granitic crust between the strike-slipfaults (e.g., Miller and Yount, 2002).

Increasing right-lateral shear in the easternMojave has implications on how shear is dis-tributed along the entire plate boundary. Sincemuch of the additional shear predates theopening of the Gulf of California (Oskin etal., 2001), it implies ;50 km of dextral shearbetween 6 and 12 Ma in the Sonora region.The total magnitude of separation of the BajaPeninsula from Sonora predicted from themodel is 350 km, 300 km of which is post 6Ma. This is slightly greater than the 296 6 20km, 276 6 10 km of which is post 6 Ma mea-sured by Oskin and Stock (2003), but still sig-nificantly less than the 450 km total continen-tal separation proposed by Fletcher (2003).

Dokka and Travis (1990) proposed that theeastern California shear zone accommodated9%–14% of total predicted relative motion be-tween plates if shear initiated at 10 Ma. Themodel of eastern California shear zone defor-mation that we propose here (Animation 1)suggests that eastern California shear zone de-

formation is ;28% of San Andreas motionaveraged since 12 Ma and 15% of total platemotion since 16 Ma.

Arizona–Mexican Basin and Range

The geographic region that has the fewestlocal kinematic constraints is Sonora–ChihuahuaMexico. However, the kinematics of Baja Cal-ifornia, based on plate tectonic reconstructions(Atwater and Stock, 1998), is an especiallypowerful constraint on intraplate deformationin this region. The constraint arises from thesimple fact that oceanic and continental lith-osphere cannot occupy the same surface areaat the same time (Atwater and Stock, 1998)(Fig. 6B). The plate tectonic constraint sug-gests ;330 km 6 50 km of extension between6 Ma and 24 Ma, because after restoring theoffset across the Gulf of California (Oskin etal., 2001; Oskin and Stock, 2003), this is thetotal overlap between continent and ocean. Inconcert with strong northeast-southwest exten-sion in Arizona, we suggest similar magni-tudes of extension (44 km and 86 km) oc-curred from 16 Ma to 24 Ma and was orientedN508E–N608E (making room for the brownand green curves in Fig. 6B). We show anoth-er pulse from 12 Ma to 8 Ma orientedN658W–N788W, reflecting the growing influ-ence of the Pacific plate’s northerly motion on

intraplate deformation, as appears to be thecase to the north (Animation 1).

Restoring 330 km of extension, however,particularly the northwesterly extension in thewindow of time from 16 Ma to 8 Ma, opensup a large northeast-trending gap in southernArizona and northern Sonora. This gap is aresult of differences in both magnitude andtiming of extension between southern Arizonaand northern Sonora and suggests (incorrect-ly) that there is ;60 km of NW-SE compres-sion between 16 and 8 Ma (Figs. 8–9). Largemagnitude core complex extension in southernArizona initiates at ca. 28 Ma and wanes from16 Ma to 14 Ma (Table 3). Significant exten-sion in Sonora occurs over a similar timerange (Nourse et al., 1994; Gans, 1997). Atca. 12 Ma, however, significant extension isrecorded in both the Gulf extensional provincewest of the Sierra Madre Occidental (e.g.,Stock and Hodges, 1989; Henry, 1989; Lee etal., 1996, Gans et al., 2003) and east of theSierra Madre Occidental (Henry and Aranda-Gomez, 2000), while only minimal magni-tudes of east-west extension are recorded insouthern Arizona. This problem is similar tothat arising from the difference in timing ofextension north of the Colorado River exten-sional corridor between the Mojave Desertand central Basin and Range. Here, the Gar-lock fault accommodates different amounts ofextension, not only from 10 Ma to the present(Davis and Burchfiel, 1973), but potentiallythroughout the history of extension in the re-gion (24–0 Ma). Although the difference intiming and magnitude of extension betweenthe Mojave region and the southern ArizonaBasin and Range versus the Mexican Basinand Range in Sonora and Chihuahua isgenerally recognized (e.g., Henry and Aranda-Gomez, 2000; Dickinson, 2002), the geometryand genetic relationship of the transfer systemthat must separate them is problematic.

In the model presented here, the amount ofextension in the Mexican Basin and Range ispartitioned between the extending regions east(;134 km) and west (;180 km) of the un-strained Sierra Madre Occidental block. Al-though both regions display numerous exten-sional structures, the exact magnitude ofextension is unknown. Because of the differ-ence in post–16 Ma extension in Chihuahuaand the Rio Grande rift (90 and 20 km, re-spectively) after ca. 16 Ma, the model includesa zone of right-lateral shear that extendsthrough southeastern Arizona between the twoprovinces (Animation 1). The existence of thisshear zone is unlikely, leaving two possiblesolutions. The first is that extension system-atically increases from the Rio Grande rift to



Chihuahua Mexico due to clockwise rotationof the Sierra Madre Occidental (rotationwould need to be greater than the 1.58 rota-tional opening of the Rio Grande rift). Anoth-er solution would be partitioning a muchgreater magnitude of extension in the Gulf ex-tensional province (;270–300 km), but this isthus far not supported by mapping in the re-gion (Henry and Aranda-Gomez, 2000). Mostlikely some combination of these factors isnecessary to match the first-order geologicconstraints of the region.

Sierra Nevada–Great Valley BlockRotation

The reconstruction presented here showssignificant extension in the northern Basin andRange between 36 Ma and 24 Ma, with es-sentially no extension occurring over this timeperiod in the central Basin and Range. To ac-commodate this difference, the Sierra Nevada–Great Valley Block must rotate or deform in-ternally. We propose that the block behavesfairly rigidly and rotates counterclockwise(Animation 1). After initiation of extension inthe central Basin and Range at ;16 Ma, theSierra Nevada–Great Valley Block rotatesclockwise for a final net rotation of 28 (Table5, Appendix 1, Movement Table [see footnote1]). The animation shows the early 36–24 Marotation accommodated by ;35 km of dextralshear along the proto–Garlock fault and ac-companying compression in the southeasternSierra Nevada region (Animation 1). The ac-tual effects of this rigid body rotation on thedeformation of surrounding regions (particu-larly to the north and south) are highly depen-dent on the axis of rotation and how rigidlythe block behaved, both of which are un-known. The rotation of the Tehachapi Moun-tains may include this early counterclockwiserotation of the Sierras, as well as potentiallybeing linked to southern Basin and Rangecore-complex formation, which immediatelyfollowed (McWilliams and Li, 1985; Plesciaand Calderone, 1986; Walker et al., 1995;Glazner et al., 2002).

Areas West of the San Andreas Fault

Based on the timing and magnitude of dis-placement on a few fault systems (San An-dreas, northern Gulf of California, Mojave,central Basin and Range, and the Santa YnezMountains), continental basins must open(creation of white spaces in the movie [Ani-mation 1, Figs. 7–9] suggesting pulses of ex-tension) and close (closing of spaces or over-lap of polygons suggesting pulses of

contraction) from 24 Ma to 0 Ma. Even at thislarge and relatively simplified scale, extensionand contraction are spatially and temporallycomplex throughout the region west of theSan Andreas fault, and we expect even greatercomplexities in timing and magnitude at amore detailed level. The following discussionhighlights the magnitudes of displacement andsummarizes data that either support or conflictwith the model displacements.

Transverse RangesThe clockwise rotation of the Western

Transverse Ranges (Hornafius et al., 1986; Lu-yendyk, 1991) suggests regions of extensionand subsequent compression both north andsouth of the rotating Santa Ynez Mountainsblock (Fig. 2, range 50) (Animation 1). Themagnitude of predicted extension (Fig. 8) andcontraction (Fig. 7) (oriented ;north-south) isas great as 130 km to the north of the westernside of the block from ca. 12 Ma to the pres-ent. Motion of Baja California northward from6 Ma to the present suggests as much as 90km of shortening in the southern TransverseRanges (Santa Ynez and San Gabriel Moun-tains blocks) (Fig. 7, Animation 1). Transpres-sive motion involving the San Gabriel Moun-tains, San Bernardino Mountains, and Mojaveblocks implies ;40 km of north-south short-ening immediately north of the PeninsularRanges block. Balanced cross sectionsthrough the San Emigdio, Santa Ynez, andSan Gabriel Ranges indicate 53 km of short-ening since 3 Ma (Namson and Davis, 1988a).Although the shortening estimate is stronglydependent on the details of how the SantaYnez and Peninsular Ranges–Baja Californiablocks move, the reconstruction presentedhere suggests ;60 km of north-south short-ening at the longitude of the eastern SantaYnez Mountains block since 6 Ma. As sug-gested by Namson and Davis (1988a), short-ening of this magnitude in the upper mantlelithosphere is supported by a large volume ofhigh-velocity material imaged tomographical-ly beneath the region (e.g., Humphreys et al.,1984).

Coast RangesDifferences in the timing of extension with-

in the Mojave and Basin and Range north andsouth of the Garlock fault, in conjunction withplate tectonic constraints on the westernmostlimit of the North America continental edge(Atwater and Stock, 1998), indicate a periodof extension (20–16 Ma) and subsequent com-pression (14–0 Ma) to the west of the Sierra–Great Valley block (Figs. 7–9, Animation 1).Approximately 80 km of core-complex exten-

sion south of the Garlock fault occurred priorto significant extension in the central Basinand Range. In order to maintain a quasilinearocean-continent boundary, a zone of extensionroughly equal in magnitude to the core-complexextension is required north of the Garlockfault and west of the Sierra Nevada–Great Val-ley block. This becomes most visible in thereconstruction at 16 Ma (Fig. 9A). As exten-sion evolves in the central Basin and Range,this same zone undergoes contraction to main-tain the quasilinear plate boundary suggestedby the extant distribution of oceanic crustfrom 16 Ma to the present.

The Neogene tectonic and volcanic historyfrom the Great Valley to the edge of the con-tinent is broadly consistent with the model(data summarized in Tennyson, 1989). Al-though the model and geologic data are diffi-cult to compare quantitatively because thereare no obvious normal faults with measurableoffsets, the magnitude of extension (and sub-sequent compression) is significantly less thanthat predicted by the model. Development oflocal nonmarine basins and eroded highs, fol-lowed by significant subsidence at ;16–18Ma and the development of the relatively deepmarine Monterey basin strongly suggests anextensional event. Rotation of the TehachapiMountains and/or extension in the southernSan Joaquin Valley (McWilliams and Li,1985; Plescia and Calderone, 1986; Tennyson,1989; Goodman and Malin, 1992) may be in-dicative of this extension but may representfar less than the ;80 km predicted by themodel.

The subsequent compression in the CoastRanges is more quantifiable and appears to besignificantly less than that suggested by themodel. Estimates of compression in the CoastRanges east and west of the San Andreas faultrange from 20 km to 48 km (Page et al., 1998;Namson and Davis, 1990, 1988b), with all ofthe known shortening occurring post–10 Ma,and most of it post–4 Ma (Page et al., 1998;Namson and Davis, 1990). Therefore, themodel predicts an additional 32–50 km ofshortening prior to 10 Ma, for which there is(thus far) no evidence in the Coast Ranges.

Pausing Animation 1 at 15 Ma highlightsthe crux of the problem (Fig. 9a). To eliminatethe need of early 24–16 Ma extension in theCoast Ranges (and subsequent compression),the continental edge would need to bend east-ward north of the Mojave and then continuenorth along the western edge of the Great Val-ley (Animation 1). This bend in the continen-tal edge would create an ;80-km-wide,;300-km-long section of oceanic crust thatwould have to be subducted south of the



northward migrating triple junction during theperiod of central Basin and Range extension.The solution to the space problem that themodel highlights may rest in a combination ofseveral possibilities which include allowingfor a warping of the North America coast line,finding greater magnitudes of deformation inthe region of the Coast Ranges, and less ex-tension in the central Basin and Range. How-ever, to truly evaluate the magnitude of eachof these options requires more detailed recon-struction of crustal blocks west of the San An-dreas fault.

Uncertainties in the Reconstruction

Statistically rigorous uncertainties are no-toriously difficult to quantify in geological re-constructions, largely because estimates ofgeologic offset do not have Gaussian or otherstandard probability distribution functions.The condition of strain compatibility or ‘‘nooverlap’’ sets a hard limit on the displacementestimate but does not distinguish higher orlower probability of any given position withinthose limits. Hence, the variance of any givenestimate cannot be rigorously quantified.

In map view, any given displacement esti-mate will have an irregularly shaped uncer-tainty region. Under the assumption of a uni-form probability distribution within theseuncertainty regions, Wernicke et al. (1988)used a Monte Carlo method to estimate thetotal uncertainty on the sum of displacementvectors for a path across the central Basin andRange. This method repeatedly summed ran-domly selected vectors from each uncertaintyregion to generate a probability distributionfor the net offset. The contour that excludedthe outermost 5% of the model runs was takenas an estimate of two standard deviations ofthe measurement. The estimate of total Sierranmotion thus derived was 247 km 6 56 km, S758 6 128E, and therefore a reasonable esti-mate of the standard deviation would be 28km. For this same estimate, the square root ofthe sum of the squares for individual vectors(in the direction of displacement, using valuesfrom Table 1 and Figure 10 in Wernicke et al.,1988) is only 15 km. This is perhaps not sur-prising because the Monte Carlo approachdoes not place greater weight on values nearthe center of the uncertainty polygon than onvalues at the edges.

Our revised displacement estimate for thecentral Basin and Range, 235 km 6 20 km(again the error is equal to the square root ofthe sum of the squares for individual vectors),is similar to that of Wernicke et al. (1988) ifone considers the 20 km figure as a crude es-

timate of the standard deviation (1-sigma).However, given the results from Wernicke etal. (1988), the real error may scale upward byas much as a factor of two, depending on thedegree to which our best estimate is moreprobable than values at the extremes. A simplesum of each uncertainty along a given pathfrom Table 1 and Table 2 gives an error esti-mate of 47 km and 45 km, respectively. Thus,as a rule of thumb, the uncertainty in positionof any given range or set of ranges at anygiven time is on the order of 20–40 km at onestandard deviation.

Because the reconstruction involves tem-poral information (which is also uncertain),the problem of rigorously estimating errorsbecomes even more difficult and is clearly be-yond the scope of this paper. Even thoughtemporal information adds to the uncertaintyof position at any given time, the self-consistency of the reconstruction mitigatesthese uncertainties to a substantial degree.

EVOLUTION OF THE REGIONALVELOCITY FIELD

Tracking the restored positions of the rang-es from the palinspastic maps, we have cre-ated ‘‘instantaneous’’ velocity fields based on2 m.y. averages from 0 Ma to 18 Ma and 6m.y. averages from 18 to 36 Ma. These pa-leogeodetic velocity fields depict how defor-mation has evolved in space and time acrossthe plate boundary deformation zone (Figs.10A–10G).

Figures 10F and 10G (30–18 Ma) illustratethe collapse of the Basin and Range awayfrom the stable Colorado Plateau through theformation of metamorphic core complexes ata time of active ignimbrite volcanism andPacific-Farallon convergence. Extension initi-ated first in the northern Basin and Range andthen in the southern Basin and Range. Thispulse of large-magnitude extension migratedsouth and north, respectively, until it con-verged in the central Basin and Range at ca.16 Ma. Figure 10E (14–16 Ma) emphasizesthe large extensional strains in the central Ba-sin and Range especially with respect to theconcurrent faulting to the north and south. The14–16 Ma time slice also shows the impact ofthe evolving plate boundary on the NorthAmerican continent as right-lateral shear is ac-commodated through the rotation of the West-ern Transverse Ranges and accompanyingshear and extension. The 10–12 Ma time slice(Fig. 10D) illustrates the uniform (systemati-cally increasing) strain in the northern Basinand Range and, in contrast, the westward-mi-grating extension in the central Basin and

Range. Significant extension is also necessaryin the Mexican Basin and Range due to plate-boundary constraints. It is during this time pe-riod that right-lateral shear migrates farther in-board into the continent through thedevelopment of the eastern California shearzone. South of the Garlock fault, the shear isoriented nearly parallel to the plate boundary(N258W). North of the Garlock fault, the shearplus extension creates a more oblique orien-tation of shear (;N678W). From 6 Ma to 8Ma, this same pattern of intracontinental right-lateral shear strengthens with shear partitioneddifferently south of the Garlock fault than inthe central Basin and Range and northern Ba-sin and Range portions of the eastern Califor-nia shear zone (Fig. 10C). In the Mexican Ba-sin and Range, deformation wanes andextension and right-lateral shear become con-centrated in the proto–Gulf of California.

The differences in the velocity fields fromthe 2–4 Ma average to the 0–2 Ma average ismost likely a function of limitations in thedata, rather than a significant slowing in therate of deformation over the last 2 m.y. (i.e.,the Mojave region) (Figs. 10A and 10B).Within the model, the lack of timing con-straints for right-lateral faults through the Mo-jave means that the rate of deformation therebecomes a function of the rate of deformationto the north and south. North of the Garlockfault, large magnitudes (104 km) of obliqueextension are focused predominately from 11Ma to 3 Ma (Niemi et al., 2001; Snow andWernicke, 2000; Snow and Lux, 1999). Southof the Mojave, the timing of deformation ispartially bracketed by the age of rotation ofthe Eastern Transverse Ranges (as mentionedearlier, ca. 10 Ma rocks record the entire 458of rotation whereas ca. 4 Ma rocks indicate norotation; Carter et al., 1987; Richard, 1993).These timing constraints suggest most of thedeformational shear in the Mojave occurredbetween 10 Ma and 2 Ma. However, the totaldisplacement across the eastern Californiashear zone (100 km 6 10 km) averaged overthe last 12 m.y. suggests a long-term rate of8.3 mm/yr 6 1 mm/yr. This rate is similar toor slightly less than the 8–12 mm/yr rate sug-gested by geodetic studies (McClusky et al.,2001; Miller et al., 2001; Sauber et al., 1994;Savage et al., 1990).

Another way to look at the evolution of thevelocity field and provide a direct comparisonbetween geologic data and geodynamicalmodel results is by mapping the paths that in-dividual ranges take over the deformationalinterval of interest (Fig. 11). Note that thebend in the path of the Pacific plate does notappear to be related to changes in the paths of



Figure 10. ‘‘Instantaneous’’ velocity fields based on 2 m.y. averages from 0 to 18 Ma, and 6 m.y. averages from 18 to 36 Ma. Arrowsshow displacement with respect to stable North America and were determined by connecting the centroids of specific ranges at one timewith the centroid of the same range in a later time. Because the motion of individual ranges can be very slight at the eastern edge ofthe model, the line lengths representing each incremental offset were uniformly doubled. Map base is the palinspastic map from theyoungest time in the 2 or 6 m.y. interval.

the Sierra Nevada with respect to the ColoradoPlateau or changes in the paths of individualranges within the continent. The most signif-icant continental change in direction occurs at12 Ma. Because the plate constraints do notrequire the bend to occur at that time (it is

only a function of the times at which magneticanomalies constrain the position), it is possi-ble within the uncertainties of both the platereconstruction and geological reconstruction(Atwater and Stock, 1998; Wernicke andSnow, 1998) that these events more closely

correlate. As stated previously, the timing ofdevelopment of right-lateral shear depends onthe orientation and timing of early extensionin the Death Valley region, which if relativelyminor prior to 11 Ma would point toward alater time of onset of right-lateral shear in-



Figure 10. (continued).

board of the Sierra Nevada. The distributionof north-northwest shear through the Mojaveis kinematically linked to the northwesterlymotion of the Sierra Nevada–Great Valleyblock, in turn requiring at least some amountof right-lateral shear within the Mojave regionbetween 12 Ma and 8 Ma.

CONCLUSIONS

Although orogen-scale reconstructions ofthe Basin and Range will continue to evolvewith time and adjust as more data is acquired,the exercise in kinematic compatibility wepresent here highlights what we understand

and more importantly what we still do not un-derstand regarding the evolution of the plateboundary.

Results that are robust and highlight whatwe do understand include: (1) 235 km 6 20km of extension oriented N788W in both thenorthern (50% extension) and central (200%



Figure 11. Map illustrating paths of various ranges from 0 to 36 Ma. Solid black circlesindicate the positions of the ranges at 8 Ma, and open circles represent the positions ofthe ranges at 12 Ma. The westernmost point on each line represents the current locationof each range. The easternmost point on the path represents the location of the range at36 Ma. The blue arrows represent the motion of the Mendicino triple junction, with itsposition shown at 24, 15, 8, and 0 Ma (Atwater and Stock, 1998).

extension) parts of the province. An importantimplication of the model is that any significantchange in extension amount in a portion of theregion (i.e., a range on the path between theColorado Plateau and the Sierra Nevada) mustbe evaluated in light of how that change af-fects coevolving regions to the north andsouth. (2) A significant portion of boundary-parallel shear (in contrast to earlier extension)jumped into the continent at ca. 10–12 Ma,and once established, appears to have migrat-ed westward with time. (3) The magnitude ofslip on the eastern California shear zone ap-pears to be 100 km 6 10 km, although theexact structures that accommodate this shearin the Mojave, or how much of the relativemotion is accommodated by distributed shear,is not known.

Problems with the current reconstructions

are highlighted by large gaps in the model.These zones emphasize areas where morework is needed in refining our ideas abouthow intraplate deformation is accommodatedthrough time. Salient aspects of the model thatwe do not understand include: (1) compatibil-ity between timing of extension north andsouth of the Garlock fault and a smooth north-northwest–trending continental edge as im-plied by plate tectonic reconstructions. Tomaintain a relatively smooth continental edgewith different periods of extension across theGarlock fault, a triangular window of signifi-cant extension (.50 km; 24–16 Ma) followedby an equal amount of shortening (14–0 Ma)would have occurred in the Coast Range–Great Valley region. While known geologysupports extension and subsequent compres-sion in these time windows, the magnitude is

;25% of what is needed; and (2) differencesin magnitude and timing of extension betweensouthern Arizona and northern Sonora, Mex-ico, require a transfer zone or large lateral dis-placement gradient. The model displays thiszone as a gap that opens up (going backwardwith time) between the two provinces. Timingand magnitude of extension in the Sonora re-gion were constrained only by plate motionsto the west and broad assumptions as to sim-ilarities in timing and direction with areas tothe north. Data detailing the magnitude, tim-ing, and direction of extension through theMexican Basin and Range is necessary to re-solve this problem.

ACKNOWLEDGMENTS

This paper has benefited greatly from many con-versations with scientists familiar with westernNorth America geology. We specifically want to ac-knowledge Tanya Atwater, Bill Dickinson, AllenGlazner, Steve Graham, Jon Spencer, Joann Stock,Nathan Niemi, Mike Oskin, Jason Saleeby, andJohn Suppe. We are grateful to Melissa Brennemanat the University of Redlands for creating theArcMap document and script used for the recon-struction. The movie would not exist without thehelp of the University of California, Santa Barbara,Educational Multimedia Visualization Center, spe-cifically Carrie Glavich and Grace Giles. GaryAxen, Doug Walker, Craig Jones, and Randy Kellerall provided insightful feedback through the reviewprocesses that greatly improved the clarity of pre-sentation. This project was funded by the CaltechTectonics Observatory.

REFERENCES CITED

Abbott, P.L., and Smith, T.E., 1989, Sonora Mexico, sourcefor the Eocene Poway conglomerate of southern Cal-ifornia: Geology, v. 17, p. 329–332, doi: 10.1130/0091-7613(1989)017,0329:SMSFTE.2.3.CO;2.

Allmendinger, R.W., Farmer, H., Hauser, E.C., Sharp, J.,Von Tish, D., Oliver, J., and Kaufman, S., 1986, Phan-erozoic tectonics of the Basin and Range—ColoradoPlateau transition from COCORP data and geologicdata, in Barazangi, M., and Brown, L.D., eds., Re-flection seismology: The continental crust: AmericanGeophysical Union Geodynamics Series, v. 14,p. 257–268.

Allmendinger, R.W., Royse, F., Anders, M.H., Christie-Blick, N., and Wills, S., 1995, Is the Sevier Desertreflection of west-central Utah a normal fault?: Com-ment: Geology, v. 23, p. 669–670, doi: 10.1130/0091-7613(1995)023,0669:ITSDRO.2.3.CO;2.

Anders, M.H., and Christie-Blick, N., 1994, Is the SevierDesert reflection of west-central Utah a normal fault?:Geology, v. 22, p. 771–774, doi: 10.1130/0091-7613(1994)022,0771:ITSDRO.2.3.CO;2.

Atwater, T., 1970, Implications of plate tectonics for theCenozoic tectonic evolution of western North Amer-ica: Geological Society of America Bulletin, v. 81,p. 3513–3536.

Atwater, T., and Stock, J., 1998, Pacific–North AmericaPlate tectonics of the Neogene southwestern UnitedStates; an update, in Ernst, W.G., and Nelson, C.A.,eds., Integrated Earth and environmental evolution ofthe southwestern United States: The Clarence A. Hall,Jr. volume: Columbia, Bellwether Publishing, p. 393–420.

Axen, G.J., Wernicke, B.P., Skelly, M.J., and Taylor, W.J.,1990, Mesozoic and Cenozoic tectonics of the Sevier



thrust belt in the Virgin River Valley area, southernNevada, in Wernicke, B., ed., Basin and Range exten-sional tectonics near the latitude of Las Vegas, Ne-vada: Boulder, Colorado, Geological Society of Amer-ica Memoir 176, p. 123–153.

Ballard, S.N., 1990, The structural geology of the LittleMaria Mountains, Riverside County, California [Ph.D.thesis]: Santa Barbara, University of California, 206 p.

Bartley, J.M., and Glazner, A.F., 1991, En echelon Miocenerifting in the southwestern United States and modelfor vertical-axis rotation in continental extension: Ge-ology, v. 19, p. 1165–1168, doi: 10.1130/0091-7613(1991)019,1165:EEMRIT.2.3.CO;2.

Bartley, J.M., and Wernicke, B.P., 1984, The Snake Rangedecollement interpreted as a major extensional shearzone: Tectonics, v. 3, p. 647–657.

Bassett, A.M., and Kupfer, D.H., 1964, A geologic recon-naissance in the southeastern Mojave Desert, Califor-nia: Special report: California Division of Mines andGeology, v. 83, p. 1–43.

Bennett, R.A., Davis, J.L., and Wernicke, B.P., 1999,Present-day pattern of Cordilleran deformation in thewestern United States: Geology, v. 27, p. 371–374,doi: 10.1130/0091-7613(1999)027,0371:PDPOCD.2.3.CO;2.

Bennett, R.A., Wernicke, B.P., Niemi, N.A., Friedrich,A.M., and Davis, J.L., 2003, Contemporary strainrates in the northern Basin and Range province fromGPS data: Tectonics, v. 22, p. 1008, doi: 10.1029/2001TC001355.

Bird, P., 1998, Kinematic history of the Laramide orogenyin latitudes 35–49 N, western United States: Tecton-ics, v. 17, p. 780–801, doi: 10.1029/98TC02698.

Bogen, N.L., and Schweickert, R.A., 1985, Magnitude ofcrustal extension across the northern Basin and RangeProvince; constraints from paleomagnetism: Earth andPlanetary Science Letters, v. 75, no. 1, p. 93–100, doi:10.1016/0012-821X(85)90054-8.

Bohannon, R.G., and Geist, E., 1998, Upper crustal struc-ture and Neogene tectonic development of the Cali-fornia continental borderland: Geological Society ofAmerica Bulletin, v. 110, p. 779–800, doi: 10.1130/0016-7606(1998)110,0779:UCSANT.2.3.CO;2.

Brady, R., Wernicke, B., and Fryxell, J., 2000, Kinematicevolution of a large-offset continental normal faultsystem, South Virgin Mountains, Nevada: GeologicalSociety of America Bulletin, v. 112, p. 1375–1397,doi: 10.1130/0016-7606(2000)112,1375:KEOALO.2.0.CO;2.

Braun, J., and Pauselli, C., 2004, Tectonic evolution of theLachlan Fold Belt, southeastern Australia: Constraintsfrom coupled numerical models of crustal deformationand surface erosion driven by subduction of the un-derlying mantle: Physics of the Earth and PlanetaryInteriors, v. 141, p. 281–301, doi: 10.1016/j.pepi.2003.11.007.

Burchfiel, B.C., Hodges, K.V., and Royden, L.H., 1987,Geology of Panamint Valley–Saline Valley pull apartsystem, California: Palinspastic evidence for low-angle geometry of a Neogene range-bounding fault:Journal of Geophysical Research, v. 92,p. 10,422–10,426.

Carr, W.J., Byers, F.M., Jr., and Orkild, P.P., 1986, Strati-graphic and volcano-tectonic relations of Crater FlatTuff and some older volcanic units, Nye County, Ne-vada: Reston, Virginia, U.S. Geological Survey, U.S.Geological Survey Professional Paper 1323, 28 p.

Carter, J.N., Luyendyk, B.P., and Terres, R.R., 1987, Neo-gene clockwise tectonic rotation of the eastern Trans-verse Ranges, California, suggested by paleomagneticvectors: Geological Society of America Bulletin,v. 98, p. 199–206, doi: 10.1130/0016-7606(1987)98,199:NCTROT.2.0.CO;2.

Cashman, P.H., and Fontaine, S.A., 2000, Strain partition-ing in the northern Walker Lane, western Nevada andnortheastern California: Tectonophysics, v. 326,p. 111–130, doi: 10.1016/S0040-1951(00)00149-9.

Cemen, I., Wright, L.A., Drake, R.E., and Johnson, F.C.,1985, Cenozoic sedimentation and sequence of defor-mational events at the southeastern end of FurnaceCreek strike-slip fault-zone, Death Valley region, Cal-ifornia, in Biddle, K.T., and Christie-Blick, N., eds.,

Strike-slip deformation, basin formation, and sedimen-tation: Tulsa, Oklahoma, Society for Sedimentary Ge-ology (SEPM), Society of Economic Paleontologistsand Mineralogists Special Publication 37, p. 127–139.

Chapin, C.E., and Cather, S.M., 1994, Tectonic setting ofthe axial basins of the northern and central Rio Granderift, in Keller, G.R., and Cather, S.M., ed., Basins ofthe Rio Grande rift: Structure, stratigraphy, and tec-tonic setting: Geological Society of America SpecialPaper 291, p. 5–25.

Coney, P.J., 1980, Cordillera metamorphic core complexes:An overview, in Crittenden, M.D., Coney, P.J., andDavis, G.H., eds., Cordilleran metamorphic core com-plexes: Geological Society of America Memoir 153,p. 7–31.

Coogan, J.C., and DeCelles, P.G., 1996, Seismic architec-ture of the Sevier Desert detachment basin: Evidencefor large-scale regional extension: Geology, v. 24,p. 933–936, doi: 10.1130/0091-7613(1996)024,0933:ECATSD.2.3.CO;2.

Coogan, J.C., DeCelles, P.G., Mitra, G., and Sussman, A.J.,1995, New regional balanced cross section across theSevier Desert region and central Utah thrust belt: Geo-logical Society of America Abstracts with Programs,v. 27, no. 4, p. 7.

Crouch, J.K., and Suppe, J., 1993, Late Cenozoic tectonicevolution of the Los Angeles basin and inner Califor-nia borderland: A model for core-complex–like crustalextension: Geological Society of America Bulletin,v. 105, p. 1415–1434, doi: 10.1130/0016-7606(1993)105,1415:LCTEOT.2.3.CO;2.

Davis, G.A., 1977, Limitations on displacement and south-eastward extent of the Death Valley fault zone, Cali-fornia: Short contributions to California Geology:Special report: California Divisions of Mines and Ge-ology, v. 129, p. 27–33.

Davis, G.A., and Burchfiel, B.C., 1973, Garlock Fault: Anintracontinental transform structure, southern Califor-nia: Geological Society of America Bulletin, v. 84,p. 1407–1422, doi: 10.1130/0016-7606(1973)84,1407:GFAITS.2.0.CO;2.

Davis, G.A., and Lister, G.S., 1988, Detachment faulting incontinental extension: Perspectives from the south-western U.S. Cordillera, in Clark, S.P., Jr., Burchfiel,B.C., and Suppe, J., eds., Processes in continental lith-ospheric deformation: Geological Society of AmericaSpecial Paper 218, p. 133–159.

Davy, P., Guerin, G., and Brun, J.-P., 1989, Thermal con-straints on the tectonic evolution of a metamorphiccore complex (Santa Catalina Mountains), Arizona:Earth and Planetary Science Letters, v. 94,p. 425–440, doi: 10.1016/0012-821X(89)90159-3.

Dibblee, T.W., Jr., 1964, Geologic map of the Ord Moun-tains quadrangle, San Bernardino County, California:U.S. Geological Survey Miscellaneous Geologic In-vestigations Map I-427, 1 sheet, scale: 1:62,500.

Dibblee, T.W., Jr., 1968, Geologic map of the TwentyninePalms quadrangle, San Bernardino and Riversidecounties, California: U.S. Geological Survey Miscel-laneous Geologic Investigations Map I-561, 1 sheet,scale: 1:62,500.

Dibblee, T.W., Jr., 1982, Regional geology of the TransverseRanges Province of southern California, in Fife, D.,ed., Geology and mineral wealth of the CaliforniaTransverse ranges: Santa Ana, California: Santa Ana,South Coast Geological Society, Inc., p. 7–26.

Dickinson, W.R., 1991, Tectonic setting of faulted Tertiarystrata associated with the Catalina core complex insouthern Arizona: Geological Society of America Spe-cial Paper 264, p. 106.

Dickinson, W.R., 1996, Kinematics of transrotational tec-tonism in the California Transverse Ranges and itscontribution to cumulative slip along the San Andreastransform fault system: Geological Society of AmericaSpecial Paper 305, p. 46.

Dickinson, W.R., 2002, The Basin and Range province asa composite extensional domain: International Geol-ogy Review, v. 44, no. 1, p. 1–38.

Dickinson, W.R., and Wernicke, B.P., 1997, Reconciliationof San Andreas slip discrepancy by a combination ofinterior basin-range extension and transrotation near

the coast: Geology, v. 25, p. 663–665, doi: 10.1130/0091-7613(1997)025,0663:ROSASD.2.3.CO;2.

Dilles, J.H., and Gans, P.B., 1995, The chronology of Ce-nozoic volcanism and deformation in the Yeringtonarea, western Basin-and-Range and Walker Lane:Geological Society of America Bulletin, v. 107,p. 474–486, doi: 10.1130/0016-7606(1995)107,0474:TCOCVA.2.3.CO;2.

Dillon, J.T., 1975, Geology of the Chocolate and CargoMuchacho Mountains, southeasternmost California[Ph.D. thesis]: Santa Barbara, University of Califor-nia, 405 p.

Dokka, R.K., 1983, Displacements on late Cenozoic strike-slip faults of the central Mojave Desert, California:Geology, v. 11, p. 305–308, doi: 10.1130/0091-7613(1983)11,305:DOLCSF.2.0.CO;2.

Dokka, R.K., 1989, The Mojave extensional belt of south-ern California: Tectonics, v. 8, p. 363–390.

Dokka, R.K., and Travis, C.J., 1990, Late Cenozoic strike-slip faulting in the Mojave Desert, California: Tecton-ics, v. 9, no. 2, p. 311–340.

Dokka, R.K., Ross, T.M., and Lu, G., 1998, The TransMojave-Sierran shear zone and its role in early Mio-cene collapse of southwestern North America, inHoldsworth, B., Dewey, J., and Strachan, R., eds.,Continental transpressional and transtensional tecton-ics: Geological Society Special Publication 135,p. 183–202.

Duebendorfer, E.M., and Black, R.A., 1992, The kinematicrole of transverse structures in continental extension:An example from the Las Vegas Valley shear zone,Nevada: Geology, v. 20, p. 1107–1110, doi: 10.1130/0091-7613(1992)020,1107:KROTSI.2.3.CO;2.

Duebendorfer, E.M., Beard, L.S., and Smith, E.I., 1998,Restoration of Tertiary deformation in the Lake Meadregion, southern Nevada; the role of strike-slip trans-fer faults, in Faulds, J.E., and Stewart, J.H., eds., Ac-commodation zones and transfer zones; the regionalsegmentation of the Basin and Range province:Geological Society of America Special Paper 323,p. 127–148.

England, P., and Houseman, G., 1986, Finite strain calcu-lations of continental deformation. 2. Comparisonwith the India-Asia collision zone: Journal of Geo-physical Research, v. 91, p. 3664–3676.

England, P., and McKenzie, D., 1982, A thin viscous sheetmodel for continental deformation: Geophysical Jour-nal of the Royal Astronomical Society, v. 70,p. 295–321.

Faulds, J.E., Henry, C.D., and Hinz, N.H., 2005, Kinemat-ics of the northern Walker Lane; an incipient trans-form fault along the Pacific-North American Plateboundary: Geology, v. 33, p. 505–508, doi: 10.1130/G21274.1.

Fayon, A.K., Peacock, S.M., Stump, E., and Reynolds Ste-phen, J., 2000, Fission track analysis of the footwallof the Catalina deatchment fault, Arizona: Tectonicdenudation, magmatism and erosion: Journal of Geo-physical Research, v. 105, p. 11,047–11,062, doi:10.1029/1999JB900421.

Fitzgerald, P.G., Fryxell, J.E., and Wernicke, B.P., 1991,Miocene crustal extension and uplift in southeasternNevada: Constraints from apatite fission track analy-sis: Geology, v. 19, p. 1013–1016, doi: 10.1130/0091-7613(1991)019,1013:MCEAUI.2.3.CO;2.

Flesch, L.M., Holt, W.E., Haines, A.J., and Shen-Tu, B.,2000, Dynamics of the Pacific–North American plateboundary in the western United States: Science,v. 287, p. 834–836, doi: 10.1126/science.287.5454.834.

Fletcher, J.M., 2003, Tectonic restoration of the Baja Cali-fornia microplate and the geodynamic evolution of thePacific-North American plate margin: Geological So-ciety of America Abstracts with Programs, v. 35,no. 4, p. 9.

Fletcher, J.M., Bartley, J.M., Martin, M.W., Glazner, A.F.,and Walker, J.D., 1995, Large-magnitude continentalextension: An example from the central Mojave meta-morphic core complex: Geological Society of AmericaBulletin, v. 107, no. 12, p. 1468–1483, doi: 10.1130/0016-7606(1995)107,1468:LMCEAE.2.3.CO;2.

Foster, D.A., Gleadow, A.J.W., Reynolds, S.J., and Fitzger-



ald, P.G., 1993, Denudation of metamorphic core com-plexes and the reconstruction of the Transition Zone,west-central Arizona; constraints from apatite fissiontrack thermochronology: Journal of Geophysical Re-search, v. 98, p. 2167–2185.

Fowler, T.K., Jr., and Calzia, J.P., 1999, Kingston Rangedetachment fault, southeastern Death Valley region,California; relation to Tertiary deposits and recon-struction of initial dip, in Wright, L.A., and Troxel,B.W., eds., Cenozoic basins of the Death Valley re-gion: Geological Society of America Special Paper333, p. 245–257.

Frei, L.S., 1986, Additional paleomagnetic results from theSierra Nevada: Further constraints on Basin andRange extension and northward displacement in thewestern United States: Geological Society of AmericaBulletin, v. 97, p. 840–849, doi: 10.1130/0016-7606(1986)97,840:APRFTS.2.0.CO;2.

Frei, L.S., Magill, J.R., and Cox, A., 1984, Paleomagneticresults from the central Sierra Nevada: Constraints onreconstructions of the western United States: Tecton-ics, v. 3, p. 157–177.

Gans, P.B., 1997, Large-magnitude Oligo-Miocene exten-sion in southern Sonora: Implications for the tectonicevolution of northwest Mexico: Tectonics, v. 16,p. 388–408, doi: 10.1029/97TC00496.

Gans, P.B., and Miller, E.L., 1983, Style of mid-Tertiaryextension in east-central Nevada: Utah Geology andMineral Survey Special Studies, v. 59, p. 107–160.

Gans, P.B., Blair, K., MacMillan, I., Wong, M., and Roldan,J., 2003, Structural and magmatic evolution of theSonoran rifted margin: A preliminary report: Geolog-ical Society of America Abstracts with Programs,v. 35, no. 4, p. 21.

Gans, P.B., Miller, E.L., McCarthy, J., and Ouldcott, M.L.,1985, Tertiary extensional faulting and evolvingductile-brittle transition zones in the northern SnakeRange and vicinity; new insights from seismic data:Geology, v. 13, p. 189–193, doi: 10.1130/0091-7613(1985)13,189:TEFAED.2.0.CO;2.

Gilder, S., and McNulty, B.A., 1999, Tectonic exhumationand tilting of the Mount Givens pluton, central SierraNevada, California: Geology, v. 27, p. 919–922, doi:10 .1130 /0091-7613(1999)027,0919 :TEA-TOT.2.3.CO;2.

Glazner, A.F., Bartley, J.M., and Walker, J.D., 1989, Mag-nitude and significance of Miocene crustal extensionin the central Mojave Desert, California: Reply: Ge-ology, v. 17, p. 1061–1062, doi: 10.1130/0091-7613(1989)017,1061:CAROMA.2.3.CO;2.

Glazner, A.F., Walker, J.D., Bartley, J.M., and Fletcher,J.M., 2002, Cenozoic evolution of the Mojave Blockof southern California, in Glazner, A.F., Walker, J.D.,and Bartley, J.M., eds., Geologic evolution of the Mo-jave Desert and southwestern Basin and Range: Geo-logical Society of America Memoir 195, p. 19–41.

Goodman, E.D., and Malin, P.E., 1992, Evolution of thesouthern San Joaquin Basin and mid-Tertiary ‘‘tran-sitional’’ tectonics, central California: Tectonics, v. 11,p. 478–498.

Graham, S.A., Stanley, R.G., Bent, J.V., and Carter, J.R.,1989, Oligocene and Miocene paleogeography of cen-tral California and displacement along the San An-dreas fault: Geological Society of America Bulletin,v. 101, p. 711–730, doi: 10.1130/0016-7606(1989)101,0711:OAMPOC.2.3.CO;2.

Guth, P.L., 1989, Day 4. Tertiary extension in the SheepRange Area, northwestern Clark County, Nevada, inWernicke, B.P., Snow, J.K., Axen, G.J., Burchfiel,B.C., Hodges, K.V., Walker, J.D., and Guth, P.L., eds.,Extensional tectonics in the Basin and Range Provincebetween the southern Sierra Nevada and the ColoradoPlateau: Washington D.C., Field Trip GuidebookT138, 28th International Geological Congress, Amer-ican Geophysical Union, p. 33–39.

Hamilton, W.B., 1987, Mesozoic geology and tectonics ofthe Big Maria Mountains region, southeastern Cali-fornia, in Dickinson, W.R., and Klute, M.A., eds., Me-sozoic rocks of southern Arizona and adjacent areas:Arizona Geological Society Digest, v. 18, p. 33–47.

Hardyman, R.F., Ekren, E.B., and Proffett, J., 1984, Tertiarytectonics of west-central Nevada—Yerington to Gabbs

Valley, Western Geological Excursions, Guidebook,volume 4: Reno, Mackay School of Mines, Depart-ment of Geological Sciences, p. 160–231.

Henry, C.D., 1989, Late Cenozoic Basin and Range struc-ture in western Mexico adjacent to the Gulf of Cali-fornia: Geological Society of America Bulletin,v. 101, p. 1147–1156, doi: 10.1130/0016-7606(1989)101,1147:LCBARS.2.3.CO;2.

Henry, C.D., and Aranda-Gomez, J.J., 2000, Plate interac-tions control middle–late Miocene, proto-Gulf and Ba-sin and Range extension in the southern Basin andRange province: Tectonophysics, v. 318, p. 1–26, doi:10.1016/S0040-1951(99)00304-2.

Hintze, L.F., 1973, Geologic road logs of western Utah andeastern Nevada: Brigham Young University ResearchStudies, Geology Series, v. 20, part 2, no.7, 66 p.

Hoisch, T.D., and Simpson, C., 1993, Rise and tilt of meta-morphic rocks in the lower plate of a detachment faultin the Funeral Mountains, Death Valley, California:Journal of Geophysical Research, v. 98, no. 4,p. 6805–6827.

Holm, D.K., and Dokka, R.K., 1991, Major late Miocenecooling of the middle crust associated with extensionalorogenesis in the Funeral Mountains, California: Geo-physical Research Letters, v. 18, no. 9, p. 1775–1778.

Holm, D.K., and Dokka, R.K., 1993, Interpretation and tec-tonic implications of cooling histories; an examplefrom the Black Mountains, Death Valley extended ter-rane, California: Earth and Planetary Science Letters,v. 116, no. 1–4, p. 63–80, doi: 10.1016/0012-821X(93)90045-B.

Holm, D.K., Snow, J.K., and Lux, D.R., 1992, Thermal andbarometric constraints on the intrusive and unroofinghistory of the Black Mountains; implications for tim-ing, initial dip, and kinematics of detachment faultingin the Death Valley region, California: Tectonics,v. 11, no. 3, p. 507–522.

Holm, D.K., Geissman, J.W., and Wernicke, B., 1993, Tiltand rotation of the footwall of a major normal faultsystem: Paleomagnetism of the Black Mountains,Death Valley extended terrane, California: GeologicalSociety of America Bulletin, v. 105, no. 10,p. 1373–1387, doi: 10.1130/0016-7606(1993)105,1373:TAROTF.2.3.CO;2.

Holt, W.E., Chamot-Rooke, N., Le Pichon, X., Haines, A.J.,Shen, T.B., and Ren, J., 2000, Velocity field in Asiainferred from Quaternary fault slip rates and globalpositioning system observations: Journal of Geophys-ical Research, v. 105, p. 19,185–19,210, doi: 10.1029/2000JB900045.

Hope, R.A., 1966, Geology and structural setting of theeastern Transverse Ranges, southern California [Ph.D.thesis]: Los Angeles, University of California, 201 p.

Hornafius, J.S., Luyendyk, B.P., Terres, R.R., and Kamer-ling, M.J., 1986, Timing and extent of Neogene tec-tonic rotation in the western Transverse Ranges, Cal-ifornia: Geological Society of America Bulletin, v. 97,p. 1476–1487, doi: 10.1130/0016-7606(1986)97,1476:TAEONT.2.0.CO;2.

Houseman, G., and England, P., 1986, Finite strain calcu-lations of continental deformation. 1. Method and gen-eral results for convergent zones: Journal of Geo-physical Research, v. 91, p. 3651–3663.

Howard, K.A., and Miller, D.M., 1992, Late Cenozoicfaulting at the boundary between the Mojave and Son-oran blocks; Bristol Lake area, California, in Richard,S.M., ed., Deformation associated with the Neogene,eastern California shear zone, southeastern Californiaand southwestern Arizona; proceedings: Redlands,California, San Bernardino County Museum Associ-ation, San Bernardino County Museum AssociationSpecial Publication 92–1, p. 37–47.

Hudson, D.M., and Oriel, W.M., 1979, Geologic map of theBuckskin Range, Nevada, Nevada Bureau of Minesand Geology, no. 64, 1 sheet, scale 1:18,000.

Hudson, M.R., Sawyer, D.A., and Warren, R.G., 1994, Pa-leomagnetism and rotation constraints for the middleMiocene southwestern Nevada volcanic field: Tecton-ics, v. 13, no. 2, p. 258–277, doi: 10.1029/93TC03189.

Humphreys, E.D., 1995, Post-Laramide removal of the Far-allon slab, western United States: Geology, v. 23,

p. 987–990, doi: 10.1130/0091-7613(1995)023,0987:PLROTF.2.3.CO;2.

Humphreys, E.D., Clayton, R.W., and Hager, B.H., 1984,A tomographic image of mantle structure beneathsouthern California: Geophysical Research Letters,v. 11, no. 7, p. 625–627.

Ingersoll, R.V., 2001, Structural and stratigraphic evolutionof the Rio Grande Rift, northern New Mexico andsouthern Colorado: International Geology Review,v. 43, no. 10, p. 867–891.

Ingersoll, R.V., Devaney, K.A., Geslin, J.K., Cavazza, W.,Diamond, D.S., Heins, W.A., Jagiello, K.J., Marsaglia,K.M., Paylor, E.D., II, and Short, P.F., 1996, The MudHills, Mojave Desert, California: Structure, stratigra-phy, and sedimentology of a rapidly extended terrane:Geological Society of America Special Paper 303,p. 61–84.

Jackson, M., 1991, Paleoseismology of Utah, volume 3:The number and timing of Holocene paleoseismicevents on the Nephi and Levan segments, Wasatchfault zone, Utah: Utah Geological Survey SpecialStudy 78, 23 p.

John, B.E., and Foster, D.A., 1993, Structural and thermalconstraints on the initiation angle of detachment fault-ing in the southern Basin and Range: The ChemehueviMountains case study: Geological Society of AmericaBulletin, v. 105, p. 1091–1108, doi: 10.1130/0016-7606(1993)105,1091:SATCOT.2.3.CO;2.

Lavier, L.L., and Buck, W.R., 2002, Half graben versuslarge-offset low-angle normal fault: Importance ofkeeping cool during normal faulting: Journal of Geo-physical Research, v. 107, p. 2122, doi: 10.1029/2001JB000513.

Lee, J., 1995, Rapid uplift and rotation of mylonitic rocksfrom beneath a detachment fault: Insights from potas-sium feldspar 40Ar/39Ar thermochronology, northernSnake Range, Nevada: Tectonics, v. 14, p. 54–77, doi:10.1029/94TC01508.

Lee, J., Miller, M.M., Crippen, R., Hacker, B., and LedesmaVazquez, J., 1996, Middle Miocene extension in theGulf Extensional Province, Baja California: Evidencefrom the southern Sierra Juarez: Geological Society ofAmerica Bulletin, v. 108, p. 505–525, doi: 10.1130/0016-7606(1996)108,0505:MMEITG.2.3.CO;2.

Lewis, C.J., Wernicke, B.P., Selverstone, J., and Bartley,J.M., 1999, Deep burial of the footwall of the northernSnake Range decollement, Nevada: Geological Soci-ety of America Bulletin, v. 111, p. 39–51, doi:10.1130/0016-7606(1999)111,0039:DBOTFO.2.3.CO;2.

Long, K.B., Baldwin, S.L., and Gehrels, G.E., 1995, Tec-tonothermal evolution of the Pinaleno-Jackson Moun-tain core complex, southeast Arizona: Geological So-ciety of America Bulletin, v. 107, p. 1231–1240, doi:10.1130/0016-7606(1995)107,1231:TEOTPO.2.3.CO;2.

Lund, K., Beard, S.L., and Perry, W.J., 1993, Relation be-tween extensional geometry of the northern GrantRange and oil occurrences in Railroad Valley, east-central Nevada: AAPG Bulletin, v. 77, p. 945–962.

Luyendyk, B.P., 1991, A model for Neogene crustal rota-tions, transtension, and transpression in southern Cal-ifornia: Geological Society of America Bulletin,v. 103, p. 1528–1536, doi: 10.1130/0016-7606(1991)103,1528:AMFNCR.2.3.CO;2.

Machette, M.N., Personius, S.F., and Nelson, A.R., 1992,Paleoseismology of the Wasatch fault zone; a sum-mary of recent investigations, interpretations, and con-clusions, in Gori, P.L., and Hays, W.W., eds., Asses-ment of regional earthquake hazards and risk alongthe Wasatch Front, Utah:U.S. Geological Survey Pro-fessional Paper, v. 1500-A, p. A1–A71.

Martin, M.W., Glazner, A.F., Walker, J.D., and Schermer,E.R., 1993, Evidence for right-lateral transfer faultingaccommodating en echelon Miocene extension, Mo-jave Desert, California: Geology, v. 21, p. 355–358,doi: 10.1130/0091-7613(1993)021,0355:EFRLTF.2.3.CO;2.

Matthews, V., III, 1976, Correlation of Pinnacles and Nee-nach volcanic formations and their bearing on the SanAndreas problem: American Association of PetroleumGeologists Bulletin, v. 51, p. 2128–2141.



McClusky, S.S., Bjornstad, S., Hager, B., King, R., Meade,B., Miller, M., Monastero, F., and Souter, B., 2001,Present-day kinematics of the Eastern California ShearZone from a geodetically constrained block model:Geophysical Research Letters, v. 28, p. 3369–3372,doi: 10.1029/2001GL013091.

McQuarrie, N., Stock, J.M., Verdel, C., and Wernicke, B.P.,2003, Cenozoic evolution of Neotethys and implica-tions for the causes of plate motions: Geophysical Re-search Letters, v. 30, p. 2036, doi: 10.1029/2003GL017992.

McWilliams, M.O., and Li, Y., 1985, Oroclinal folding ofthe southern Sierra Nevada batholith: Science, v. 230,p. 172–175.

Miller, D.M., and Yount, J.C., 2002, Late Cenozoic tectonicevolution of the north-central Mojave Desert inferredfrom fault history and physiographic evolution of theFort Irwin area, in Glazner, A.F., Walker, J.D., andBartley, J.M., eds., Geologic evolution of the MojaveDesert and southwestern Basin and Range: GeologicalSociety of America Memoir 195, p. 173–198.

Miller, E.L., Gans, P.B., and Garing, J., 1983, The SnakeRange decollement: An exhumed mid-Tertiary ductile-brittle transition: Tectonics, v. 2, p. 239–263.

Miller, E.L., Dumitru, T.A., Brown, R.W., and Gans, P.B.,1999, Rapid Miocene slip on the Snake Range–DeepCreek Range fault system, east-central Nevada: Geo-logical Society of America Bulletin, v. 111, no. 6,p. 886–905, doi: 10.1130/0016-7606(1999)111,0886:RMSOTS.2.3.CO;2.

Miller, F.K., and Morton, D.M., 1980, Potassium-argon geo-chronology of the eastern Transverse Ranges andsouthern Mojave Desert, southern California, U.S.:Reston, Virginia, U.S. Geological Survey, GeologicalSurvey Professional Paper 1152, 30 p.

Miller, M., Johnson, D., Dixon, T., and Dokka, R.K., 2001,Refined kinematics of the eastern California shearzone from GPS observations, 1993–1998: Journal ofGeophysical Research, v. 106, p. 2245–2263, doi:10.1029/2000JB900328.

Namson, J.S., and Davis, T.L., 1988a, Structural transect ofthe western Transverse Ranges, California: Implica-tions for lithospheric kinematics and seismic risk eval-uation: Geology, v. 16, p. 675–679, doi: 10.1130/0091-7613(1988)016,0675:STOTWT.2.3.CO;2.

Namson, J.S., and Davis, T.L., 1988b, Seismically activefold-thrust belt in the San Joaquin Valley, central Cal-ifornia: Geological Society of America Bulletin,v. 100, p. 257–273, doi: 10.1130/0016-7606(1988)100,0257:SAFATB.2.3.CO;2.

Namson, J.S., and Davis, T.L., 1990, Late Cenozoic foldand thrust belt of the southern Coast Ranges and SantaMaria Basin, California: American Association of Pe-troleum Geologists Bulletin, v. 74, p. 467–492.

Niemi, N.A., 2002, Extensional tectonics in the Basin andRange Province and the geology of the GrapevineMountains, Death Valley Region, California and Ne-vada [Ph.D. thesis]: Pasadena, California, CaliforniaInstitute of Technology, 344 p.

Niemi, N.A., Wernicke, B.P., Brady, R.J., Saleeby, J.B., andDunne, G.C., 2001, Distribution and provenance ofthe middle Miocene Eagle Mountain Formation, andimplications for regional kinematic analysis of the Ba-sin and Range province: Geological Society of Amer-ica Bulletin, v. 113, p. 419–442, doi: 10.1130/0016-7606(2001)113,0419:DAPOTM.2.0.CO;2.

Niemi, N.A., Wernicke, B.P., Friedrich, A.M., Simons, M.,Bennett, R.A., and Davis, J.L., 2004, BARGEN con-tinuous GPS data across the eastern Basin and Rangeprovince, and implications for fault system dynamics:Geophysical Journal International, v. 159, p. 842–862,doi: 10.1111/j.1365-246X.2004.02454.x.

Nourse, J.A., Anderson, T.H., and Silver, L.T., 1994, Ter-tiary metamorphic core complexes in Sonora, north-western Mexico: Tectonics, v. 13, p. 1161–1182, doi:10.1029/93TC03324.

Oskin, M., and Stock, J., 2003, Pacific-North America platemotion and opening of the Upper Delfı́n basin, north-ern Gulf of California, Mexico: Geological Society ofAmerica Bulletin, v. 115, no. 10, p. 1173–1190, doi:10.1130/B25154.1.

Oskin, M., and Iriondo, A., 2004, Large magnitude tran-

sient strain accumulation on the Blackwater fault,Eastern California shear zone: Geology, v. 32,p. 313–316, doi: 10.1130/G20223.1.

Oskin, M., Stock, J., and Martin-Barajas, A., 2001, Rapidlocalization of Pacific–North America plate motion inthe Gulf of California: Geology, v. 29, p. 459–462,doi: 10.1130/0091-7613(2001)029,0459:RLOPNA.2.0.CO;2.

Page, B.M., Thompson, G.A., and Coleman, R.G., 1998,Late Cenozoic tectonics of the central and southernranges of California: Geological Society of AmericaBulletin, v. 110, p. 846–876, doi: 10.1130/0016-7606(1998)110,0846:OLCTOT.2.3.CO;2.

Plescia, J.B., and Calderone, G.J., 1986, Paleomagneticconstraints on the timing and extent of rotation of theTehachapi Mountains, California: Geological Societyof America Abstracts with Programs, v. 18, p. 171.

Powell, R.E., 1981, Geology of the crystalline basementcomplex, eastern Transverse Ranges, southern Cali-fornia: Constraints on regional tectonic interpretation[Ph.D. thesis]: Pasadena, California, California Insti-tute of Technology, 441 p.

Reheis, M.C., 1993, Neogene tectonism from the south-western Nevada volcanic field to the White Moun-tains, California; part II, Late Cenozoic history of thesouthern Fish Lake Valley fault zone, Nevada and Cal-ifornia, in Lahren, M.M., Trexle, J.H., Jr., and Spi-nosa, C., eds., Crustal evolution of the Great Basinand the Sierra Nevada: Reno, University of Nevada,p. 370–382.

Reheis, M.C., and Sawyer, T.L., 1997, Late Cenozoic his-tory and slip rates of the Fish Lake Valley, EmigrantPeak, and Deep Springs fault zones, Nevada and Cal-ifornia: Geological Society of America Bulletin,v. 109, no. 3, p. 280–299, doi: 10.1130/0016-7606(1997)109,0280:LCHASR.2.3.CO;2.

Reynolds, S.J., 1985, Geology of the South Mountains, cen-tral Arizona: Arizona Bureau of Geology and MineralTechnology Bulletin, v. 195, 61 p.

Richard, S.M., 1993, Palinspastic reconstruction of south-eastern California and southwestern Arizona for themiddle Miocene: Tectonics, v. 12, p. 830–854.

Richard, S.M., and Dokka, R.K., 1992, Geology of thePackard Well fault zone, southeastern California, inRichard, S.M., ed., Deformation associated with theNeogene, eastern California shear zone, southeasternCalifornia and southwestern Arizona; proceedings:Redlands, California, San Bernardino County Muse-um Association, San Bernardino County Museum As-sociation Special Publication 92–1, p. 71–74.

Richard, S.M., Fryxell, J.E., and Sutter, J.F., 1990, Tertiarystructure and thermal history of the Harquahala andBuckskin Mountains, west central Arizona: Implica-tions for denudation by a major detachment fault sys-tem: Journal of Geophysical Research, v. 95,p. 19,973–19,987.

Richard, S.M., Sherrod, D.R., and Tosdal, R.M., 1992, Ci-bola Pass fault, southwestern Arizona, in Richard,S.M., ed., Deformation associated with the Neogene,eastern California shear zone, southeastern Californiaand southwestern Arizona; proceedings: Redlands,California, San Bernardino County Museum Associ-ation, San Bernardino County Museum AssociationSpecial Publication 92–1, p. 66–70.

Ron, H., and Nur, A., 1996, Vertical axis rotation in theMojave: Evidence from the Independence dike swarm:Geology, v. 24, no. 11, p. 973–976, doi: 10.1130/0091-7613(1996)024,0973:VARITM.2.3.CO.

Rotstein, Y., Combs, J., and Biehler, S., 1976, Gravity in-vestigation in the southern Mojave Desert, California:Geological Society of America Bulletin, v. 87,p. 981–993, doi: 10.1130/0016-7606(1976)87,981:GIITSM.2.0.CO;2.

Russell, L.R., and Snelson, S., 1994, Structure and tectonicsof the Albuquerque Basin segment of the Rio GrandeRift; insights from reflection seismic data, in Keller,G.R., and Cather, S.M., eds., Basins of the Rio GrandeRift: Structure, stratigraphy, and tectonic setting: Geo-logical Society of America Special Paper 291, p. 83–112.

Sauber, J., Thatcher, W., Solomon, S., and Lisowski, M.,1994, Geodetic slip rate for the eastern Californiashear zone and the recurrence time of Mojave desert

earthquakes: Nature, v. 367, p. 264–266, doi:10.1038/367264a0.

Savage, J.C., Lisowski, M., and Prescott, W., 1990, An ap-parent shear zone trending north-northwest across theMojave Desert into Owens Valley, eastern California:Geophysical Research Letters, v. 17, p. 2113–2116.

Schermer, E.R., Luyendyk, B.P., and Cisowski, S., 1996,Late Cenozoic structure and tectonics of the northernMojave Desert: Tectonics, v. 15, no. 5, p. 905–932,doi: 10.1029/96TC00131.

Scott, R.J., Foster, D.A., and Lister, G.S., 1998, Tectonicimplications of rapid cooling of lower plate rocksfrom the Buckskin-Rawhide metamorphic core com-plex, west-central Arizona: Geological Society ofAmerica Bulletin, v. 110, p. 588–614, doi: 10.1130/0016-7606(1998)110,0588:TIORCO.2.3.CO;2.

Sieh, K., and Jahns, R.H., 1984, Holocene activity of theSan Andreas fault at Wallace Creek, California: Geo-logical Society of America Bulletin, v. 95,p. 883–896, doi: 10.1130/0016-7606(1984)95,883:HAOTSA.2.0.CO;2.

Smith, D.L., 1992, History and kinematics of Cenozoic ex-tension in the northern Toiyabe Range, Lander Coun-ty, Nevada: Geological Society of America Bulletin,v. 104, p. 789–801, doi: 10.1130/0016-7606(1992)104,0789:HAKOCE.2.3.CO;2.

Smith, D.L., Gans, P.B., and Miller, E.L., 1991, Palinspasticrestoration of Cenozoic extension in the central andeastern Basin and Range Province at latitude 39–40degrees N, in Raines, G.L., Lisle, R.E., Schafer, R.W.,and Wilkinson, W.H., eds., Geology and ore depositsof the Great Basin; symposium proceedings: Reno,Nevada, Geological Society of Nevada, p. 75–86.

Smith, R.B., and Bruhn, R.L., 1984, Intraplate extensionaltectonics of the western U.S. Cordillera—Inferenceson structural style from seismic-reflection data, re-gional tectonics and thermal-mechanical models ofbrittle ductile deformation: Journal of GeophysicalResearch, v. 89, p. 5733–5762.

Snow, J.K., 1992, Large-magnitude Permian shortening andcontinental margin tectonics in the southern Cordil-lera: Geological Society of America Bulletin, v. 104,no. 1, p. 80–105, doi: 10.1130/0016-7606(1992)104,0080:LMPSAC.2.3.CO;2.

Snow, J.K., and Lux, D.R., 1999, Tectono-sequence stratig-raphy of Tertiary rocks in the Cottonwood Mountainsand northern Death Valley area, California and Ne-vada, in Wright, L.A., and Troxel, B.W., eds., Ceno-zoic basins of the Death Valley region: Geological So-ciety of America Special Paper 333, p. 17–64.

Snow, J.K., and Prave, A.R., 1994, Covariance of structuraland stratigraphic trends; evidence for anticlockwiserotation within the Walker Lane Belt, Death Valleyregion, California and Nevada: Tectonics, v. 13, no. 3,p. 712–724, doi: 10.1029/93TC02943.

Snow, J.K., and Wernicke, B.P., 1989, Uniqueness of geo-logical correlations; an example from the Death Valleyextended terrain: Geological Society of America Bul-letin, v. 101, no. 11, p. 1351–1362, doi: 10.1130/0016-7606(1989)101,1351:UOGCAE.2.3.CO;2.

Snow, J.K., and Wernicke, B.P., 2000, Cenozoic tectonismin the central Basin and Range: Magnitude, rate anddistribution of upper crustal strain: American Journalof Science, v. 300, p. 659–719.

Spencer, J.E., and Reynolds, S.J., 1989, Middle Tertiarytectonics of Arizona and adjacent areas, in Jenney,J.P., and Reynolds, S.J., eds., Geologic evolution ofArizona: Tucson, Arizona, Arizona Geological Soci-ety, Arizona Geological Society Digest, v. 17,p. 539–574.

Spencer, J.E., and Reynolds, S.J., 1991, Tectonics of mid-Tertiary extension along a transect through west-centralArizona: Tectonics, v. 10, no. 6, p. 1024–1221.

Spencer, J.E., Richard, S.M., Reynolds, S.J., Miller, R.J.,Shafiqullah, M., Gilbert, W.G., and Grubensky, M.J.,1995, Spatial and temporal relationships between mid-Tertiary magnetism and extension in southwestern Ar-izona: Journal of Geophysical Research, Solid Earthand Planets, v. 100, no. B6, p. 10,321–10,351, doi:10.1029/94JB02817.

Stock, J.M., and Hodges, K.V., 1989, Pre-Pliocene exten-sion around the Gulf of California and the transfer of



Baja California to the Pacific Plate: Tectonics, v. 8,p. 99–115.

Stockli, D.F., 1999, Regional timing and spatial distributionof Miocene extension in the northern Basin and RangeProvince [Ph.D. thesis]: Stanford, California, StanfordUniversity, 239 p.

Stockli, D.F., Linn, J.K., Walker, J.D., and Dumitru, T.A.,2001, Miocene unroofing of the Canyon Range duringextension along the Sevier Desert Detachment, west-central Utah: Tectonics, v. 20, p. 289–307, doi:10.1029/2000TC001237.

Stockli, D. F., Surpless, B.E., Dumitru, T.A., and Farley,K.A., 2002, Thermochronological constraints on thetiming and magnitude of Miocene and Pliocene exten-sion in the central Wassuk Range, western Nevada:Tectonics, v. 21, no. 4, p. 10-1–10-17, doi: 10.1029/2001TC001295.

Stone, P., and Pelka, G.J., 1989, Geologic map of thePalen–McCoy Wilderness study area and vicinity:Riverside County, California, Geological SurveyMiscellaneous Field Investigations Map MF-2070,1 sheet, scale: 1:62,500.

Surpless, B., 1999, Tectonic evolution of the Sierra Nevada–

Basin and Range transition zone: A study of crustalevolution in extensional provinces [Ph.D. thesis]:Stanford, California, Stanford University, 186 p.

Taylor, W.J., Bartley, J.M., Lux, D.R., and Axen, G.J.,1989, Timing of Tertiary extension in the RailroadValley–Pioche Transect, Nevada: Constraints from40Ar/39Ar ages of volcanic rocks: Journal of Geophys-ical Research, v. 94, p. 7757–7774.

Tennyson, M.E., 1989, Pre-transform early Miocene exten-sion in western California: Geology, v. 17,p. 792–796, doi: 10.1130/0091-7613(1989)017,0792:PTEMEI.2.3.CO;2.

Walker, J.D., Bartley, J.M., and Glazner, A.F., 1990, Large-magnitude Miocene extension in the central MojaveDesert; implications for Paleozoic to Tertiary paleo-geography and tectonics: Journal of Geophysical Re-search, v. 95, p. 557–569.

Walker, J.D., Fletcher, J.M., Fillmore, R.P., Martin, M.W.,Taylor, W.J., Glazner, A.F., and Bartley, J.M., 1995,Connection between igneous activity and extension inthe central Mojave metamorphic core complex, Cali-fornia: Journal of Geophysical Research, v. 100,p. 10,477–10,494, doi: 10.1029/94JB03132.

Wernicke, B., 1992, Cenozoic extensional tectonics of theU.S. Cordillera, in Burchfiel, B.C., Lipman, P.W., andZoback, M.L., eds., The Cordilleran Orogen: Conter-minous U.S.: Boulder, Colorado, Geological Societyof America, The Geology of North America, v. G-3,p. 553–581.

Wernicke, B., and Snow, J.K., 1998, Cenozoic tectonism inthe central Basin and Range: Motion of the Sierran–Great Valley Block: International Geology Review,v. 40, p. 403–410.

Wernicke, B., Axen, G.J., and Snow, J.K., 1988, Basin andRange extensional tectonics at the latitude of Las Ve-gas, Nevada: Geological Society of America Bulletin,v. 100, p. 1738–1757, doi: 10.1130/0016-7606(1988)100,1738:BARETA.2.3.CO;2.

Wills, S., Anders, M.H., and Christie-Blick, N., 2005, Pat-tern of Mesozoic thrust surfaces and Tertiary normalfaults in the Sevier Desert subsurface, west-centralUtah: American Journal of Science, v. 305, p. 42–100.

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