Chemometric recognition of genetically distinct oil families in … · 2016-01-28 · Chemometric...

Chemometric recognition ofgenetically distinct oil families inthe LosAngeles basinCaliforniaK E Peters T LWright L S Ramos J E Zumberge andL B Magoon

ABSTRACT

The prolific Los Angeles basin in California may be the mostpetroliferous province on Earth per volume of sedimentary fillHowever because most exploration in the basin occurred priorto the advent of modern geochemical methods genetic rela-tionships among the various petroleum accumulations and theirsource rocks have remained speculative A training set of 24source-related biomarker and stable carbon isotope ratios for111 non- or mildly biodegraded oil samples from the basin wasused to construct a chemometric (multivariate statistics) de-cision tree The decision tree allows genetic classification ofadditional oil or source-rock extract samples that might becollected The decision tree identifies 6 tribes and a total of 12genetically distinct oil families The families have different bulkproperties such as API gravity and sulfur content which werepreviously explained as resulting from secondary processesincluding thermal maturity or biodegradation However thechemometric assignments are based on genetic properties thatreflect distinct organofacies The oil families occur in differentlocations and reservoir intervals in the basin consistent withtheir origins from different organofacies of active source rockThe source-rock depositional environment for each oil familycan be inferred using biomarker and isotope ratios The samplesshow stable carbon isotope ratios for saturate and aromatichydrocarbons that indicate different organofacies of Miocenemarine source rocks Tribes 1 and 2 straddle the central troughmainly occur east of theNewport-Inglewood fault zone (NIFZ)and show evidence of proximal clay-rich source rock depositedunder suboxic conditions with elevated angiosperm inputTribes 3ndash6 occur west of the NIFZ and show evidence of moredistal clay-poor source rock deposited under anoxic conditions

AUTHORS

K E Peters ~ Schlumberger 18ManzanitaPlace Mill Valley California 94941Department of Geological and EnvironmentalSciences Stanford University 450 Serra MallStanford California 94305 kpeters2slbcom

Kenneth E Peters is science advisor forSchlumberger having 36 years in industrygovernment andacademia Ken is the principalauthor of The Biomarker Guide (2005)Honorary Teaching Fellow at the University ofAberdeen Charles Taylor Fellow Fellow in theGeochemical Society Schlumberger NExTinstructor and consulting associateprofessor atStanfordUniversitywherehe coleads theBasinand Petroleum System Modeling IndustrialAffiliates Program (httpsbpsmstanfordedu)He is an associate editor for AAPG Bulletin andOrganic Geochemistry He was chair of the1998 Gordon Research Conference on OrganicGeochemistry chair of the AAPG ResearchCommittee (2007ndash2010) and AAPGDistinguishedLecturer (2009ndash2010) In2009hereceivedtheAlfredETreibsMedalpresentedbythe Geochemical Society In 2013 he receivedthe AAPG Honorary Member Award He twicereceived the Schlumberger Henri Doll Prize forInnovation (2009 and 2013) He has a PhD ingeochemistry from the University of Californiaat Los Angeles

T L Wright ~ Chevron Corporation(retired) 136 Jordan Avenue San AnselmoCalifornia 94960 tomwrightgeoaolcom

Thomas L Wright spent 34 years with Chevronas a geologist and is currently a consultant onsouthernCaliforniageologyHespent the1960sas an exploration geologist for the Los AngelesBasin District during the highly competitiveurban drilling boom his work involvedcompiling data from Chevron and competitordrilling into regularly updated maps and crosssections showing known and potentialstructural and stratigraphic trends He retired in1986 and assembled that data into acomprehensive paper in AAPG Memoir 52(1991) titled Structural Geology and TectonicEvolution of the Los Angeles Basin The paperis a key reference for geologic research in theLos Angeles region Tom served as president ofthe AAPG Pacific Section (1980ndash1981) and

Copyright copy2016 The American Association of Petroleum Geologists All rights reserved

Manuscript received April 8 2015 provisional acceptance June 15 2015 revised manuscript received July 132015 final acceptance August 3 2015DOI10130608031515068

AAPG Bulletin v 100 no 1 (January 2016) pp 115ndash135 115

Geochemistry and stratigraphy of the oil tribes (1ndash6 below)suggest the following source-rock organofacies

1 Suboxic upper Miocene (Delmontian) proximal clay-richshale generated low-sulfur tribe 1 and 2 oil types(~055ndash106 wt ) east of the NIFZ that show higherthermalmaturity than tribes 3ndash6The source rock for tribe 1was slightly more reducing (lower redox potential or Eh)than that for tribe 2

2 Low-sulfur tribe 2 oil (~020ndash023 wt ) is significantlymore mature and the source rock is more clay rich andreceived more angiosperm input than tribe 1

3 Anoxic upper Miocene (middlendashupper Puente) distal shalesource rock generated sulfur-rich tribe 3 oil (~142ndash158wt ) west of the NIFZ The source rock received lesshigher-plant input than the source rocks for tribes 1 and 2

4 Suboxicndashanoxic Mohnian() clay-poor shale or marl sourcerock generated tribe 4 oil west of theNIFZOneoil family intribe 4 has low sulfur whereas the other has high sulfurcontent Higher-plant input is comparable to tribe 3

5 Anoxic middlendashupper Miocene (Lower Puente ldquonodularshalerdquo) distal shale generated sulfur-rich (~124 wt ) tribe5 oil to the southwest of the NIFZ

6 Anoxic middlendashupper Miocene (Lower Modelo nodularshale equivalent) distal shale or marl generated high-sulfurtribe 6 oil (~242 wt ) to the northwest of the NIFZ atlower levels of thermal maturity than the other tribes

INTRODUCTION

The Los Angeles basin (Figure 1) has been described as therichest petroliferous basin in the world based on the amount ofpetroleum relative to the volume of sedimentary fill (Barbat1958 Yerkes et al 1965 Wright 1987 Price 1994 Priceet al 1999) Since the discovery of the Brea-Olinda field in1880 (Biddle 1991 B-Ol in Figure 1) about 67 additionalfields have been discovered including 3 of the 10 largest fieldsin California at Wilmington (1932 298 billion barrels of oil[bbo]) Huntington Beach (1920 116 bbo) and Long Beach(095 bbo California Department of Conservation 2010Table1) Supergiant oilfields contain at least 1bboof estimatedultimate recoverable petroleumGeologically the LosAngelesbasin is among the most thoroughly studied and exploredbasins in the world (eg Driver 1948 Edwards 1951Woodford et al 1954 Barbat 1958 Yerkes et al 1965Brown 1968Gardett 1971Hill 1971Harding 1973 Yeats

was a founding member (1970) of the AAPGEnvironmental Geology Committee (Chair1974ndash1977) and the Division of EnvironmentalGeology (1992) He received the Michel THalbouty Human Needs Award in 2000 forefforts to introduce data and insights fromsubsurface petroleum geology into ongoingstudies of earthquake hazards in the LosAngeles region Tom received the AAPGDistinguished Service Award in 1993 and he isan Honorary Member of the Pacific Section(1989)He has BS andMS degrees in geologyfrom Stanford University

L S Ramos ~ Infometrix Inc 11807 NorthCreek Parkway South Suite B-111 BothellWashington 98011 scott_ramosinfometrixcom

L Scott Ramos has a PhD in analyticalchemistry and chemometrics from theUniversity of Washington Scott worked at theNational Oceanographic and AtmosphericAdministration National Marine FisheriesService in Seattle the State Pollution ControlAgency in Rio de Janeiro Brazil and the FederalAmazon Research Institute in Manaus BrazilHehasworkedfor Infometrix Inc formorethan30 years His publications include studies ofcontamination by polycyclic aromatichydrocarbons essential oil characterizationand chemometrics

J E Zumberge ~ GeoMark Research Ltd9748 Whithorn Drive Houston Texas 77095jzumbergegeomarkresearchcom

John E Zumberge has a PhD in organicgeochemistry from the University of Arizonaand is the senior vice president (since 1991) ofGeoMark Research which he cofounded in1991 John was manager of geochemical andgeological research for CitiesServicendashOccidental generalmanager for RuskaLaboratories and director of geochemicalservices for Core Laboratories He has globalexperience in petroleum geochemistryfocusing on crude oil biomarkers

L B Magoon ~ Department of Geologicaland Environmental Sciences StanfordUniversity 450 Serra Mall StanfordCalifornia 94305 lmagoonstanfordedu

Leslie B Magoon is currently consultingprofessor in the Basin and Petroleum SystemModeling Industrial Affiliates Program at

116 Los Angeles Basin Oil Families

1973 Crowell 1974 Campbell and Yerkes 1976 Beyer andBartow 1987 Mayer 1987 1991 Schwartz and Colburn1987 Wright 1987 Beyer 1988 Biddle 1991 Blake 1991)It is the classicmodel of a transform-margin basin (Ingersoll andRumelhart 1999) Despite these facts surprisingly few datahave been published on the petroleum geochemistry of theLos Angeles basin Classic early work by Philippi (1965) wasbased on geochemical analyses of 14 rock samples from theDominguez and Seal Beach fields and the Shell 1 AnaheimSugar well located east and downdip from the Seal Beach andHuntington Beach fields Thisworkwas completed prior to thewidespread use of gas chromatography Rock-Eval pyrolysis orvitrinite reflectance (Ro) Significant petroleumpotential likelyremains especially in offshore areas of the basin but littleexploration has occurred since the early 1970s partly due tohigh population density Furthermore because of the largenumber of comparatively small independent leases there hasbeen little impetus to update regional understanding of thebasin using large-scale integrated geochemical studies orcomputerized basin and petroleum system modeling

The purpose of this study was to measure biomarker andstable carbon isotope ratios for approximately 150 crude oilsamples from the Los Angeles basin to improve understandingof genetic relationships and to identify oil families that will leadto the identification of petroleum systems The geochemicalcharacteristics of each oil sample were evaluated to identify atraining set in which source-related biomarker and stablecarbon isotope ratios were unaffected by secondary processessuch as extensive biodegradation or thermal maturation Thetraining set was used to create a chemometric decisiontree (eg Peters et al 2007 2008 2013) that can be used toclassify newly collected samples of crude oil or source-rockextracts Map and stratigraphic distributions of the oil familiesand their biomarker and isotope compositionswereused to inferthe identity and character of their source-rock organofacies

REGIONAL GEOLOGY

The Cenozoic geologic history of coastal California wasdominated by evolution from subduction to the presenttransform boundary between the North American and Pacificplates As part of that process the Monterey microplate in-cluding the western Transverse Ranges block was captured(Nicholson et al 1994) by the Pacific plate in the earlyMiocene (~20 Ma) and rotated clockwise by as much as 95degThe rotation which occurred at a midcrustal detachment

Stanford University (bpsmstanfordedu) Heworked 8 years for Shell Oil Company inexploration and 32 years for the US GeologicalSurvey Since 1981 he has investigated andpopularized the petroleum system throughtalks courses and AAPG Memoir 60 ThePetroleum SystemmdashFrom Source to Trap forwhich he and his coeditor received the R HDott Sr Award in 1996

ACKNOWLEDGMENTS

Several colleagues provided usefuldiscussions including Brian RohrbackStephan Graham and Ray Ingersoll We thankSchlumberger reviewers Susan Duffield andSteve Larter AAPG reviewer Jon Schwalbachand an anonymous reviewer for helping toimprove the final manuscript

Peters et al 117

surface unroofed theCatalina Schist now found inthe inner borderland province and the western LosAngeles basin The breakaway zone along thenortheastern trailing edge of the rotated blockhas since developed into the Newport-Inglewoodfault zone (NIFZ) a major internal feature of theLos Angeles basin with right-lateral displacement(Wright 1991)

The Los Angeles basin is a rhombohedral pe-troleum province in coastal southern California(~2200 mi2 [3541 km2]) that extends beyond thephysiographic margins of the present-day alluvialplain (Yerkes et al 1965) The alluvial plainis bounded by mountains and hills that exposeMesozoic or older basement rocks and Upper Cre-taceous to Pleistocene sedimentary or igneous rocksThe northwest-trending central trough is approxi-mately 45 mi (72 km) long and 20 mi (32 km)wide (Figure 1) and contains up to approximately24000 ft (7315 m) of late middle Miocene andyounger marine siliciclastic rocks overlying older

Cenozoic sedimentary andor Mesozoic basementrocksThecentral trough is borderedon the southwestby the NIFZ on the north by an eastndashwest-trendingfault and fold belt along the southern Santa MonicaMountains and on the northeast by eastndashwest-trending en echelon folds and theWhittier fault zone

The northwest trend of the NIFZ is charac-teristic of theSanAndreas transform fault system inother parts of California The NIFZ is a seismicallyactive right-lateral strike-slip fault with estimatedslip rates in theMiocenendashPliocene andHolocene of05 and 2ndash3 mmyr (002 and 008ndash012 inyr)respectively (Freeman et al 1992) The NIFZ hasmeasured right-lateral displacement of 1ndash2 km(3281ndash6562 ft) in lower Pliocene strata (Yerkeset al 1965) and approximately 3 km (9843 ft) inmiddle Miocene strata (Hill 1971) Nine oil fieldsaligned within the NIFZ that are represented bysamples in this study have total cumulative pro-duction through 2009 of 31 bbo of oil (Table 1)Also trending northwest the right-lateral Whittier

Figure 1 Map shows six tribes(tribe 1 = families 11 12 and 13tribe 2 = families 21 and 22 tribe3 = families 31 32 and 33 tribe4 = families 41 and 42 and tribes 5and 6 were not divided into fam-ilies) of crude oil samples in theLos Angeles basin determined bychemometric analysis of 24source-related biomarker andstable carbon isotope ratios (Ap-pendix) Structure-contour mapmodified from Wright (1991) andused with permission of AAPGshows base Mohnian (depth inthousands of feet) which is anupper Miocene horizon ca 14 MaCross sections AA9 and FF9 arefromWright (1991) and are shownin later figures Structural elementsare the following LCF = La Cie-negas fault NIFZ = Newport-Inglewood fault zone PVF = PalosVerdes fault SM-R= SantaMonicandashRaymond faultWF=Whittier fault Fields are the following Alo= Alondra Ban= Bandini Bel= BelmontOffshore B-Ol = Brea-Olinda BvH = Beverly Hills CoW = West Coyote CvH = Cheviot Hills Dom = Dominguez ElS = El Segundo HB =Huntington Beach Hyp = Hyperion Ing = Inglewood LA = Los Angeles LaC = Las Cienegas LAD = Downtown Los Angeles LAE = East LosAngeles LB = Long Beach LBA = Long Beach Airport PdR = Playa del Rey Pot = Potrero Ric = Richfield Rs = Rosecrans (RsE = EastRosecrans not shown) Saw= Sawtelle SB= Seal Beach SFS= Santa Fe Springs SV= San Vicente Tor= Torrance USt=Union Station VB=Venice Beach Whi = Whittier Wil = Wilmington


and Palos Verdes faults form the northeasternand southwestern edges respectively of the LosAngeles basin The northwestern margin of thebasin consists of a broad anticlinorium called thewestern shelf The southern edge of the rotatedSanta Monica Mountains the west-trending SantaMonicandashRaymond fault system forms thenorthernedge of theLosAngeles basin To the southeast thebasin is bounded by the Santa Ana Mountains andthe San Joaquin Hills

Neogene structural development of the basinwasprecededbyCretaceousndashPaleogene subductionand complex three-plate interactions (Ingersoll

2008) Neogene processes included mid-Mioceneto early Pliocene extension strike-slip fault move-ment block rotation and late Pliocene to present-day northndashsouth compression (Wright 1991)Middle Miocene transtensional rifting and blockrotation was associated with major regional sub-sidence along the length of the San Andreastransform fault system By circa 14 Ma the conti-nental borderland was characterized by closeddeepwater basins and submergedbanks Siliciclasticsediments from river systems far to the east weregenerally trapped inbasins close to the shoreline andonly theclay fraction carried in suspension reached

Table 1 Cumulative Production and Estimated Ultimate Recovery for Oil Fields in the Los Angeles Basin

The table shows the cumulative production and estimated ultimate recovery (EUR) for oil fields in the Los Angeles basin for which geochemistry is included in this study(California Department of Conservation 2010) The table also includes data for the Brea-Olinda field which was the first discovered (1880) field in the basin Sectorsinclude Central (central trough) Newport-Inglewood fault zone (NIFZ) West (west of NIFZ) and East (east of NIFZ) Fields in each sector are listed in the table fromnorth to south gas-to-oil ratio (GOR) was calculated by dividing total gas by total oil for each sectorAbbreviations bbl = barrels Mbbl = thousands of barrels MMCF = millions of cubic feet

Peters et al 119

the Los Angeles basin and other sediment-starvedborderland basins and banks Along the continentalslope nutrient-richmarine upwellingwas driven byprevailing winds and produced abundant biogenicsiliceous calcareous and phosphatic sedimentsLipid-rich planktonic debris from nutrient-richsurface waters was deposited in oxygen-deficientbathyal sediments where it mixed with siliciclasticsshed into the basin mainly from the north andnortheast during the lateMiocene (McCulloh et al1994) Higher-plant debris was depositedmainly innearshore settings

Throughout the middle Miocene the anoxicfloor slopes and banks of the western and southernLos Angeles basin received organic terrigenous-richsediments known in the subsurface as the ldquonodularshalerdquo Outcrop equivalents of the nodular shale in-clude theLaVidaMemberof thePuenteFormationtothe north and in the Palos Verdes Hills the AltamiraShale and Valmonte Diatomite Members of theMonterey Formation In parts of the basin the bio-genic sediments rest on siliciclastics and volcanics ofthe middle Miocene Topanga Group Elsewhere thenodular shale and its equivalents commonly lie un-conformably on Catalina Schist on metamorphicrocks similar to those in the Peninsular Ranges to thesouthandrarelyon lowerMiocenesedimentary rocks

In an earlier study Peters et al (2008) notedgeochemical similarities among the three geneti-cally distinct groups of Monterey oil samples fromdifferent coastal basins offshore California whichwere interpreted to indicate an underlying sim-plicity resulting from three source-rock orga-nofacies (1) suboxic clay- and higher-plantndashrichdetrital deposits (2) suboxic-to-anoxic marlyhemipelagic deposits and (3) anoxic carbonate-rich pelagic deposits These three oil groups arewidespread in coastal California as might beexpected if their source rocks were depositedon low-gradient slopes and in broad depres-sions similar to those in the present-day Gulf ofCalifornia Peters et al (2008) concluded thattheir geochemical data support the progradingmargin model for the deposition of the MontereyFormation (Isaacs 2001) but do not exclude thebanktopndashslopendashbasin model (Hornafius 1991)Readers are referred to Peters et al (2008) for

additional discussion of the implications of thatwork for various depositional models of theMonterey Formation

As the proximal sediment traps filled silici-clastics spilled into theadjacentbasins andbuiltdeep-sea fans and channels on the abyssal plain Significantinfluxof siliciclastics into theLosAngelesbasinbegancirca 9Ma early in the late Miocene Three primarysubmarine fans are recognized within the basin in-cluding theTarzana SanGabriel andSantaAna fans(Redin 1991) The latter two fans merge at thenortheastern edge of the basin and are called thePuente fan The upper Miocene sandstones in thesefan systems are diagenetically immature arkosic andsusceptible to low-temperature alteration

The Tarzana fan flowed southward from asource in thewestern SanGabriel Range across thepresent San Fernando Valley and Santa MonicaMountains and into the northwestern Los Angelesbasin Uplift of the Santa Monica Mountains at theend of the Mohnian (~65 Ma) cut off the flow ofthe Tarzana fan its final phase is the Delmontian(~6 Ma) Rancho sandstone in the Sawtelle andCheviot Hills fields in the northwestern corner ofthe basin In the northwestern part of the centraltrough sands of the Tarzana fanmergedwith thoseof the Puente fan during most of the late Miocene

The Puente fan originated primarily from thenorth in the eastern San Gabriel Range but it alsooriginated from the east and northeast in the SantaAna Canyon and Perris block From circa 85 to75Ma it brought amajor influxof sand into theSanGabriel Valley across the floor of the Los Angelesbasin and through lower portions of the NIFZ Inthe Puente Hills and north-central part of thebasin the Soquel Member of the Puente Forma-tion represents this sand unit During the lateMohnian and Delmontian (~75 to 5 Ma) upliftalong the Whittier fault and its northwestern ex-tension (Alhambra high) formed an intermittentsill and sands were funneled through gaps in theWhittier Narrows area where upper-fan channelsare preserved Throughout the remainder of thebasin widespread Delmontian sandstone bodies arethinner and less common and sediments of that ageare predominately silt and clay Diatomite is also asignificantcomponentof theDelmontian sediments


By the early Pliocene (~45 Ma) siliciclasticsediments of the Puente fan had filled the SanGabriel basin andwere spilling into theLosAngelesbasin through the Whittier Narrows to spreadbroadly across the abyssal plain Distal sands of thePuente fan progressively onlapped the western shelfof the basin throughout late Miocene and Pliocenelocally interfingering with Puente Formation pe-troleum source rock By the early Pleistocene thenorthern shoreline of the basin had progradedsouthward to and beyond the NIFZ The de-positional environment was inner neritic to non-marine (Blake 1991)

Quaternary deformation formed or enhancedthe structural traps that hold most of the oil in theLos Angeles basin This deformation resulted incontinued development of the central troughSince the end of the Pliocene the axis of the troughhas been downwarped more than 1 km (3281 ft)and the flanks were uplifted by a nearly equalamount Middle and upper Miocene Puente For-mation petroleum source rock is now buried todepths of 2ndash7 km (6562ndash22966 ft) within thecentral trough

The Puente Formation in the Los Angeles basinis an equivalent of the Monterey Formation whichis a major petroleum source rock throughout muchof southern California that was deposited mainly asdistal organic-rich diatomaceous and phosphaticshale in oxygen-poor deep-marine silled basins(Demaison andMoore 1980 Pisciotto andGarrison1981) or in topographic lows on a transgressed slope(Isaacs 2001) Anoxic conditions and strong bi-ological oxygen demand associated with upwell-ing of nutrient-rich water were reinforced bybasin topography Sulfate-reducing bacteria inthe water column and shallow sediments gener-ated hydrogen sulfideMost sulfide combineswithchemically reactive iron in clay-rich sediments toform pyrite However because of low clay con-tent in some areas much of this sulfur was in-corporated into Monterey organic matter duringdiagenesis resulting in type IIS kerogen (atomicsulfurcarbon gt 004 gt8 wt sulfur) that gen-erates sulfur-rich crude oil (gt2 wt sulfur) (Orr1986 Baskin and Peters 1992)

Crude oil from the sulfur-rich organofacies ofthe Puente Formation in the Los Angeles basincommonly shows high sulfur (gt2 wt ) and high2830-bisnorhopane typical of source-rock anoxiaAnother organofacies of the Puente Formation oc-curs along the landward northern flank of the LosAngeles basin Unlike the more common distalorganofacies the landward organofacies is moreclay rich and contains type II and IIIII kerogenthat yields low-sulfur crude oil with evidence ofhigher-plant input (Jeffrey et al 1991McCullohet al 1994)

METHODS

Laboratory Analyses

Detailed procedures used by GeoMark ResearchLtd to prepare and analyze the samples are similarto those in Peters et al (2007) Briefly n-hexanewas used to remove asphaltenes from the oil sam-ples Saturate and aromatic hydrocarbons wereseparated by column chromatography using hexaneand dichloromethane respectively Stable carbonisotope ratios were determined using a FinniganDelta E isotope-ratio mass spectrometer SaturateC15+ biomarkers were analyzed using a Hewlett-Packard (HP) 7890 gas chromatograph interfacedtoanHP5975mass spectrometerTheHP-2column(50 m middot 02 mm internal diameter 011-mm filmthickness)wasprogrammed from150degC to325degCat2degCmin Themass spectrometerwas run in selectedion monitoring mode using mass-to-charge (mz)177 191 205 217 218 221 231 and 259 forsaturates andmz133 156 170 178 184 192 198231 239 245 and 253 for aromatics Responsefactors were determined by comparing mz 221for a deuterated standard (d4-C29 20R steraneChiron Laboratories Norway) with terpane (mz191) and sterane (mz 217) standards

Sample Screening

Samples excluded from the training set include(1) heavily biodegraded oil (rank 5 or more on

Peters et al 121

the 1ndash10 scale of Peters and Moldowan [1993]Figure 2) and (2) highlymature light oil (APIgt 40deg)or condensate (API gt 50deg) where biomarkers arelow or absent (eg lt10 ppm steranes) Source-related biomarker and carbon isotope ratios (seeAppendix) for the remaining 111 non- or mildlybiodegraded oil samples were used as a trainingset to construct a chemometric decision tree thatallows genetic classification of some samplesthat were excluded from the training set and

additional oil or source-rock extracts that mightbe collected

Chemometric Decision Tree

Hierarchical cluster and principal component anal-yses (Pirouette software Infometrix Inc) based onthe source-related data described below allow ra-pid assessment of genetic relationships among theoil samples and can be used to identify 6 distinctpetroleum tribes or 12 families (Figure 3) In thisdiscussion a tribe consists of crude oil samples thatare broadly similar in their geochemical character-istics but may have originated from different sourcerocks A family is a generic division of a tribe thatconsists of geochemically similar samples that orig-inated from the same or a very similar source rockBased on the source-related data a unique multi-tiered decision tree was created (InStep softwareInfometrix Inc) to categorize additional crude oilsamples from the Los Angeles basin (Figure 4)Details of the method are described in Peters et al(2007) We used geochemical expertise and prin-cipal component loadings to select 24 genetic geo-chemical parameters that differentiate the samples(see the Appendix) Table 2 includes average valuesfor several key biomarker and isotope ratios thatare indicative of the source-rock organofacies foreach oil family Complete data for the samples areavailable by subscription from GeoMark ResearchLtd (2015)

Four bulk parameters in Table 2 were excludedfrom the chemometric analysis because they arereadily altered by biodegradation or extensive ther-mal maturity API gravity sulfur content saturatearomatic hydrocarbon ratio and the weight percentltC15hydrocarbon fraction Several other parametersin the table include the methylphenanthrene index(MPI-1) (Radke et al 1982) and triaromatic ste-roid cracking ratio (TAS3[CR] modified fromMackenzie et al [1981] as described in Peters et al[2005]) and the dibenzothiophenephenanthrene(DBTP) (Hughes et al 1995) vanadiumnickel(VNi) (Lewan 1984) and C28C29 steraneratios (Grantham and Wakefield 1988)

Figure 2 (A) Quasi-sequential biodegradation scale (modifiedfrom Peters andMoldowan 1993 and reprinted with permission byChevronTexaco Exploration and Production Technology Com-pany a division of Chevron USA Inc) used to select oil samplesfor the chemometric training set (B) Oil samples from CheviotHills (CvH27) Sawtelle North (SwN28) and Wilmington (Wil78bottom) fields that show biodegradation ranks of 0 1 and 5respectively The Wilmington oil was excluded from the trainingset because of the potential for biodegradation of steranes thatwere used in the chemometric analysis but it was later assignedto family 41 using the chemometric decision tree PM = 0ndash10biodegradation scale of Peters and Moldowan (1993) UCM =unresolved complex mixture


RESULTS AND DISCUSSION

Family Assignments and Map Distributions

Hierarchical cluster analysis of the 24 selectedbiomarker and isotope ratios identifies six genet-ically distinct oil tribes (Figure 3) Principal com-ponent analysis further differentiates the tribesinto 12 families that were used to create thechemometric decision tree (Figure 4) Tribes 1and 2 occur mainly east of the NIFZ (Figure 1)and tribes 3ndash6 occur to the west of that fault Eachfamily shows different ranges of values for keybiomarker and isotope ratios that can be used tointerpret source-rock depositional environmentor organofacies (Table 2) They also show differ-ent bulk properties including API gravity sulfurcontent saturatearomatic hydrocarbon ratio andwt ltC15 fraction in different areas and res-ervoir intervals within the basin consistent withtheir origins from distinct organofacies as dis-cussed below

The results of the chemometric study aresurprising because most previous work concludedthat differences in the bulk properties of oil sam-ples from the Los Angeles basin are due to sec-ondary processes such as biodegradation or thermalmaturity (eg Jeffrey et al 1991) However ina short abstract based mainly on sulfur contentMcCulloh et al (1994) concluded that crude oilcompositions in the basin are also determined bykerogen composition Basin location influencedthe composition of kerogen in the source-rock de-positional setting and the availability of iron tosequester microbial hydrogen sulfide as pyriteespecially prior to 65MaAt the distal edge of thebasin far from terrigenous input (the major ironsource) type IIS kerogen was inferred to generatesulfur-rich oil at low thermal maturity Alongthe landward (northerly) basin flank kerogenwith lower sulfur content (types II and IIIII) wasinferred to generate low-sulfur oil

In the following section selected biomarkerand isotope ratios (Table 2) are used to describe thesource-rock depositional environment for each oilfamily Stable carbon isotope ratios for the saturateand aromatic fractions of the oil samples indicate

Miocene source rock dominated bymarine organicmatter input (Figure 5) Miocene oil samples arecharacterizedby stable carbon isotope ratios (d13C)more positive than -235permil (Chung et al 1992)Differences in the d13C of Miocene source-rockextracts and related oil compared with othersamples fromCalifornia are reflected in the isotopecomposition of kerogen above and below the basalNeogene boundary (Jones 1987 Peters et al1994 Andrusevich et al 1998) With a few ex-ceptions oil samples from tribes 1 and 2 originatedfrom a more proximal clay-rich (eg elevated18a-trisnorheohopane17a-trisnorhopane [TsTm]low norhopanehopane [C29H] and DBTPTable 2) and oxic source-rock depositional set-ting (eg low C35C34S and 2830-bisnorhopanehopane [BNHH]) that received more terrigenousorganic matter including more vascular plant andangiosperm (flowering vascular plant) input (ele-vated C19C23 and oleananehopane [OlH] re-spectively Figure 6) than tribes 3ndash6 Peters et al(2005) and references therein describe how thesebiomarker ratios in crude oil can be used to de-scribe the source-rock depositional environmentincluding relative oxicity lithology and organicmatter input Additional key references for in-terpretationof eachbiomarker parameter are givenin the discussion below and in the footnote forTable 2

Based on their distributions tribes 1 and 2originated from the central trougheast of theNIFZwhereas tribes 3ndash6 originated from depocenters tothe west of the NIFZ (Figure 1) Samples fromtribes 1 and 2 occur in updip pools along inferredmigration paths that radiate from deeply buriedsource rock in the central trough Tribe 2 samplesshow high thermal maturity based on MPI-1 andTAS3(CR) (Table 2) Tribes 3ndash5 include samplesfrom the giant Wilmington Long Beach andHuntington Beach fields Wilmington and theadjacent oil fields including the Long BeachHuntington Beach and Seal Beach fields encom-pass no more than 10 of the basin area yet theycontain about 52 bbo or about 58 of the totalconventional petroleum resource (Wright 1991)Tribe 6 occupies the northwestern portion of thestudy area and shows lower thermal maturity than

Peters et al 123

the other samples These conclusions are discussedbelow in more detail

Geochemical Characterization of the OilFamilies

Tribe 1Families 11 12 and 13 (6 8 and 19 samplesrespectively Table 2) are geochemically similar butare widespread to the east of the NIFZ Family 11samples straddle the southeastern portion of thecentral trough along a northeastndashsouthwest trend(Figure 1) Three samples occur in the WestCoyote field (CoW546 CoW547 and CoW548)to the northeast and the other three samples occurin the Seal Beach (SB448) Long Beach Airport(LBA492) and Belmont Offshore (Bel542) fieldsto the southwest Unlike nearly all other tribe 1 oilsamples the sample from Belmont Offshore ap-pears to have migrated across the NIFZ from thecentral trough Family 12 mainly consists of sam-ples from the Santa Fe Springs field (SFS457SFS460 SFS461 SFS487 SFS488 SFS572 andSFS573) but it also includes one sample from the

Sawtellefield (Saw575) far to the northwest Basedon the anomalous location of Saw575we suspect alabeling problem and that it may actually representan oil sample from elsewhere in the basin How-ever we cannot reject this sample based on theavailable data Family 13 oil samples show a curveddistribution around the northwestern northernand northeastern portions of the central troughin multiple fields (Figure 1) including Whittier(Whi42Whi581Whi582 andWhi583) Santa FeSprings (SFS456 and SFS571) Los Angeles (LA467and LA470) East Los Angeles (LAE468 andLAE469) Potrero (Pot475) Inglewood (Ing484Ing485 Ing554 Ing556 and Ing557) DowntownLos Angeles (LAD559) Richfield (Ric563) andUnion Station (USt578)

The source rock for tribe 1was depositedunderslightlymore reducingdepositional conditions thanthat for tribe 2 (eg C35C34S ~071ndash081 versus~061ndash064 respectively Table 2) Elevated C35

hopanes are typical of petroleum generated fromsource rock deposited under reducing to anoxicconditions (Peters and Moldowan 1991) Tribe 1also shows significantly higher DBTP than tribe 2(~018ndash021 versus ~005ndash007) indicating a rel-atively clay-poor source rock (Hughes et al 1995)The source rock for tribe 1 received less angio-sperm input than tribe 2 based on lower OlH(~0143ndash0260 versus 0298ndash0516 respectivelyMoldowan et al 1994)

Figure 3 Hierarchical cluster analysis of source-relatedbiomarker and isotope ratios identifies six tribes (dashedsimilarity line) of crude oil samples from the Los Angeles basinSamples are identified by tribe and family in Table 2 Analyticalrepeatability (dashed repeatability line) is based on four oilsamples from overlapping depths (2518ndash3060 ft [767ndash933 m])in different wells within the Long Beach field (LB498 LB499LB500 and LB501) Samples with cluster distances greaterthan the repeatability line are geochemically distinct NIFZ =Newport-Inglewood fault zone

Figure 4 Chemometric decision tree for Los Angeles basin oilfamilies based on soft independent modeling of class analogy(SIMCA) using biomarker and isotope data for the 111 crude oilsamples in the training set Tribe 1 contains families 11 12 and 13tribe 2 contains families 21 and 22 tribe 3 contains families 31 32and 33 and tribe 4 contains families 41 and 42 Families were notdifferentiated for tribes 5 and 6


Table2

BulkPropertiesandSelected

Biom

arkerRatiosThatIndicateSource-RockOrganofaciesfor12

LosAngelesBasin

OilFamilie

s

Family

Number

ofSamples

BulkPropertiesforNo

nbiodegraded

Samples

Maturity

Shale

Carbonate

Redox

Terrigenous

Angiosperm

s

APIG

ravity

Sulfurwt

Saturates

Arom

atics

ltC

15Fraction

MPI-1

R oEq

TAS3(CR)

TsTm

C 24C 2

3C 2

9H

DBTP

C 35C 3

4SBN

HH

VNi

CVC 2

8C 2

9St

C 19C 2

3OlH

116

282ndash59(5)

100

ndash006

(4)

125

ndash013

(5)

399ndash38(5)

108

ndash018

098

ndash013

012

ndash002

050

ndash003

077

ndash005

049

ndash001

018

ndash009

081

ndash008

017

ndash008

070

ndash023

(4)-

160

ndash032

173

ndash004

0016ndash00030143ndash0017

128

326ndash20(6)

055

ndash000

(1)

133

ndash008

(6)

474ndash45(6)

112

ndash016

100

ndash011

014

ndash005

055

ndash004

086

ndash003

046

ndash002

018

ndash015

071

ndash003

018

ndash001

036

ndash048

(3)-

162

ndash012

169

ndash005

0023ndash00020219ndash0012

1319

302ndash45(13)

106

ndash091

(7)

131

ndash021

(15)

442ndash56(15)

113

ndash014

101

ndash010

016

ndash005

063

ndash009

094

ndash008

045

ndash002

021

ndash013

076

ndash009

021

ndash004

000

ndash000

(7)-

189

ndash051

160

ndash007

0035ndash00140260ndash0067

215

353ndash45(5)

020

ndash001

(3)

189

ndash021

(5)

589ndash65(5)

149

ndash019

126

ndash013

019

ndash004

083

ndash022

088

ndash005

042

ndash003

005

ndash005

064

ndash009

021

ndash008

000

ndash000

(3)-

204

ndash029

161

ndash003

0047ndash00080516ndash0115

226

326ndash21(6)

023

ndash012

(6)

157

ndash013

(6)

554ndash51(6)

139

ndash008

119

ndash005

021

ndash003

059

ndash004

090

ndash003

043

ndash001

007

ndash001

061

ndash003

015

ndash002

000

ndash000

(5)-

174

ndash042

170

ndash002

0029ndash00030298ndash0014

318

235ndash00(1)

142

ndash044

(2)

091

ndash004

(2)

301ndash69(2)

099

ndash010

092

ndash007

008

ndash001

042

ndash004

074

ndash004

054

ndash003

032

ndash011

087

ndash006

032

ndash008

045

ndash015

(4)-

188

ndash043

166

ndash004

0016ndash00040131ndash0020

325

mdashmdash

mdashmdash

104

ndash008

095

ndash006

007

ndash001

042

ndash002

072

ndash004

056

ndash001

025

ndash007

088

ndash002

034

ndash002

041

ndash003

(3)-

240

ndash019

158

ndash003

0019ndash00020140ndash0008

3315

mdash158

ndash000

(1)

098

ndash000

(1)

202ndash00(1)

113

ndash015

101

ndash010

006

ndash001

034

ndash001

070

ndash005

057

ndash002

033

ndash011

089

ndash007

028

ndash001

070

ndash000

(1)-

213

ndash019

165

ndash003

0013ndash00020116ndash0018

418

268ndash00(1)

057

ndash000

(1)

090

ndash000

(1)

423ndash00(1)

107

ndash018

097

ndash012

008

ndash004

041

ndash007

085

ndash006

057

ndash007

030

ndash010

095

ndash005

032

ndash005

026

ndash029

(5)-

263

ndash050

158

ndash003

0016ndash00020141ndash0017

427

259ndash87(4)

322

ndash062

(2)

052

ndash008

(7)

304ndash54(7)

103

ndash010

095

ndash007

009

ndash001

043

ndash002

099

ndash009

051

ndash003

071

ndash019

096

ndash011

026

ndash009

180

ndash032

(2)-

148

ndash059

164

ndash009

0017ndash00050139ndash0016

510

308ndash21(3)

124

ndash098

(3)

105

ndash042

(5)

453ndash221(5)102

ndash017

093

ndash012

008

ndash005

042

ndash014

074

ndash006

054

ndash004

025

ndash016083

ndash010

055

ndash032

013

ndash026

(4)-

152

ndash031

154

ndash009

0030ndash00090171ndash0022

614

260ndash65(7)

242

ndash034

(7)

080

ndash023

(12)

324ndash97(12)

086

ndash011

082

ndash008

007

ndash002

044

ndash005

080

ndash003

054

ndash002

055

ndash021

088

ndash013

032

ndash010

075

ndash074

(8)-

094

ndash024

144

ndash007

0024ndash00050142ndash0016

Parametersaredescribed

inPetersetal(2005)Families11121321and

22aremainlytotheeastoftheNe

wport-Inglew

oodfaultzonewhereastheremaining

sevenfamiliesaretothewestofthe

faultzoneOnlynonbiodegraded

samples

(biodegradationrank

=0on

theP

etersand

Moldowan

[1993]scale)wereu

sedforaverage

APIgravitysulfurcontentsaturatearom

atichydrocarbonsltC 1

5fractionandVNiratio

(num

bersofsamplesforaverage

valuesareinparentheses)The

DBTPandVNi

ratioswerenotu

sedinthechem

ometric

analysis

AbbreviationsBNH

H=2830-bisnorhopanehopane(KatzandElrod1983)C 1

9C 2

3=C 1

9C 2

3tricyclicterpanes(cheilanthanesZumberge1987)C 2

4C 2

3=C 2

4tetracyclicC 2

3tricyclicterpanes(Petersetal2

005)C

28C

29St=C 2

8C 2

9ste

ranes

(GranthamandWakefield1988)C 2

9H=C 2

930-norhopaneC

30hopane

(ClarkandPhilp1989)C

35SC 3

4S=C 3

5homohopane22SC 3

4homohopane22S(Petersand

Moldowan1991)CV=canonicalvariable=-253d13C s

aturate+222

d13C a

romatic-1165(Sofer1984)DBTP=dibenzothiophenephenanthrene(Hughesetal1995)MPI-1=methylphenanthreneindex=15(2-MP+3-MP)(P+1-MP+9-MP)(Radke

etal1982)O

lH=oleananeC

30hopane

(Moldowan

etal

1994)R o

Eq=

equivalentvitrinite

reflectance(Boreham

etal1

988)TAS3(CR)=

(C20+C 2

1)(C 2

0+C 2

1+C 2

6+C 2

7+C 2

8)triarom

aticsteroidsfrommz231masschrom

atogram[also

calledTA(I)TA(I+

II)asm

odified

fromMackenzieetal

(1981)

byPetersetal(2005)]

TsTm

=C 2

7222930-trisnorneohopane222930-trisnorhopane

(McKirdyetal1983)VNi

=vanadium

nickel(Lew

an1984)

Peters et al 125

Tribe 2Families 21 and 22 (five and six samples re-spectively) straddle the northern and central por-tions of the central trough respectively Family21 occurs in a limited area to the northeastof the depocenter and consists of samples fromthe Bandini (Ban471 Ban472 and Ban541) LaCienegas (LaC558) and Downtown Los Angeles(LAD560) fields Family 22 samples occurmainlyto the west of the central trough and east of theNIFZ in the Rosecrans (Rs564 and Rs565) andEast Rosecrans (RsE566 RsE567 and RsE568)fields but Family 22 also includes one samplefrom the Santa Fe Springs field (SFS570) to theeast of the central trough

Family 21 shows higher average C19C23 andOlH ratios than any other family (~0047 and0516 respectively Table 2) indicating abundanthigher-plant and angiosperm input to the sourcerock (Zumberge 1987 Moldowan et al 1994)Family22also showshighaverageC19C23 andOlH(~0029 and 0298 respectively) compared withmostotherfamiliesAverageC19C23andOlHshowa strongcorrelation for tribes1ndash4basedon thedata inTable 2 (coefficient of determinationR2 = 093)

Families 21 and 22 are more thermally maturethan the other oil families and show the highestMPI-1andTAS3(CR)(~139ndash149and019ndash021respectively Table 2) Based on the calibration ofBoreham et al (1988) families 21 and 22 havean average equivalent Ro of approximately 126

and 119 respectively whereas all other fami-lies have Ro in the range of approximately082ndash101 (Table 2) Consistent with highthermal maturity these two families show lowersulfur content (~020ndash023 wt ) and higher APIgravity (~326degndash353deg) saturatearomatic ratios(~157ndash189) and ltC15 fraction (~554ndash589Table 2) than the other families Note that allcalculationsof averageAPIgravity sulfur saturatearomatic ltC15 fraction and VNi in Table 2 arebased on only the nonbiodegraded samples in eachfamily Families 21 and 22 show very low DBTP(~005ndash007) and families 1112 and13also showlow values (~018ndash021 Table 2) compared withthe other oil families Values of DBTP less than10 typify shale source rock (Hughes et al 1995)Therefore the source rocks for tribes 1 and 2 wereproximal clay-rich shales whereas the other tribesoriginated fromdistal less clay-rich source rocks asdiscussed below

Tribe 3Families 31 32 and 33 (8 5 and 15 samplesrespectively) occur along a northwestndashsoutheasttrend to the southwest of the central trough andwest of the NIFZ Unlike the proximal source-rock setting for tribes 1 and 2 tribe 3 source rockwas deposited in a more distal setting The sourcerock for tribe 3 received relatively less clay (lowerTsTm ~034ndash042 [McKirdy et al 1983] andC24C23 ~070ndash074 [Peters et al 2005]) and

Figure 5 Sofer (1984) plotsuggests marine source rock forall six oil tribes in the Los Angelesbasin The 13C-rich isotopiccompositions of the oil samplesare consistent with Miocenesource rock as discussed in thetext


morecarbonate(higherC29H~054ndash057[ClarkandPhilp1989]andDBTP~025ndash033[Hugheset al 1995]) Also the source rock was depositedunder more reducing conditions (C35C34S~087ndash089 [Peters and Moldowan 1991] andBNHH ~028ndash034 [Katz and Elrod 1983]) ina more marine setting (canonical variable [CV]~-188 to -240 Sofer 1984) with less angio-sperm input (OlH ~0116ndash0140 Moldowanetal1994Table2)Except for theaverageMPI-1for family 33 (~113) low MPI-1 and TAS3(CR)(~099ndash104 and ~006ndash008 respectively Table 2)suggest that tribe 3 is generally less mature thantribes 1 and 2

Family 31 occurs in various widespread fieldsincluding Seal Beach (SB449) Wilmington(Wil455Wil528Wil587 andWil593) Torrance(Tor474) Dominguez (Dom482) and Hunting-ton Beach (HB552) Family 32 occurs in a limitedareawithin theWilmingtonfield (Wil453Wil454Wil586 Wil590 and Wil591) All samples infamily32fromWilmingtonfieldand14of15family33 samples fromLong Beach field (LB447 LB494LB495 LB496 LB497 LB498 LB499 LB500LB501 LB502 LB503 LB504 LB505 andLB507) were biodegraded due to shallow strati-graphic positions within these fields (3537ndash4990and 2147ndash3059 ft [1078ndash1521 and 654ndash932 m]respectively) Therefore average bulk parameters

for nonbiodegraded family 32 oil are not includedin Table 2 Family 33 has only one nonbiode-graded oil sample from a wildcat well (LB58510580 ft [3225 m]) to the northwest of the LongBeach field near theDominguez field which limitsthe reliability of the reported bulk parameters(Table 2)

Tribe 4Families 41 and 42 (8 and 7 samples respectively)occur west of the NIFZ along a northwestndashsoutheasttrend parallel to the coastline and east of thePalos Verdes Fault (PVF in Figure 1) Family 41occurs in a limited area defined by samples fromthe Wilmington (Wil79 Wil82 Wil83 Wil458Wil459 and Wil595) and Torrance (Tor473 andSTo486)fieldsAswith family 33 only the deepestoil sample in family 41 (Wil595 5600 ft [1707m])is nonbiodegraded thus precluding average bulkparameters Family 42 occurs to the northwest offamily 41 and consists of samples from the VeniceBeach (VB450andVB579)Potrero (Pot476)Playadel Rey (PdR477) Hyperion (Hyp491) El Segundo(ElS490) and Alondra (Alo540) fields

Families 41 and 42 appear to be less maturethan tribes 1 and 2 For example families 41 and42have significantly lower MPI-1 (~103ndash107) andTAS3(CR) (~008ndash009) than tribes 1 and 2 Bulkparameters for family 41 are limited to only one

Figure 6 Oleananehopaneand C19C23 tricyclic terpane ra-tios are indicative of higher-plantinput during source-rock de-position (Peters et al 2005) Higholeananehopane ratios for theLos Angeles basin oil samples(especially tribes 1 and 2) areconsistent with angiosperminput to Cenozoic source rock(Moldowan et al 1994)

Peters et al 127

nonbiodegraded sample and may be unreliableHowever family 42 also shows lower API gravity(~259deg) saturatearomatic ratio (~052) andltC15

fraction (~304 Table 2) than tribes 1 and 2Unlike tribes 1 and 2 family 42 shows high sulfurcontent (~322wt) andDBTP (~071Table 2)Crude oil from carbonate source rock typicallyshows DBTP ratios gt 1 (Hughes et al 1995) Thehigh DBTP value for family 42 compared withthe other families suggests a clay-poor shale ormarl source rock ElevatedC35C34S for families 41and 42 (~095ndash096) is consistent with a morereducing to anoxic source-rock depositional settingcompared to the other families High VNi forfamily 42 (~180) is consistentwith anoxia (Lewan1984) but VNi for family 41 is low (~026Table 2)

Tribe 5Tribe 5 consists of one family (10 samples) fromthe Huntington Beach (HB451 HB463 HB464HB465HB466 andHB553)Wilmington (Wil489Wil527 andWil588) andTorrance (Tor576) fieldsTribe 5 shows source (eg TsTm ~042 C29H~054 CV ~-152 OlH ~0171) and maturityparameters (MPI-1~102 TAS3[CR]~008) similarto tribes 3 and 4 However tribe 5 shows unusuallyhigh BNHH (~055 Table 2) Curiale et al (1985)observed a correlation between high BNH highbenzothiophene and other chemical characteristicsof Monterey-equivalent crude oil that indicatesiliciclastic-deficient source rock

The relationship between C19C23 and OlHfor tribes 5 and 6 differs from that for the other oilfamilies For each C19C23 ratio theOlH ratios fortribes 5 and 6 are somewhat less than the trendexhibited by the other families We conclude thathigher-plant contributions to the source rocksfor tribes 5 and 6 comprised proportionally lessangiosperm input than that for the other tribes

Tribe 6Tribe 6 consists of one family (14 oil samples)from El Segundo (ElS5 and ElS551) BeverlyHills (BvH26 BvH478 BvH543 and BvH544)Cheviot Hills (CvH27 and CvH479) Sawtelle

(SwN28 and Saw480) San Vicente (SV483 andSV569) Inglewood (Ing555) and Playa del Rey(PdR561) fields Tribe 6 is thermally less maturethan the other oil families based on lowMPI-1 andTAS3(CR) (~086 and 007 respectively) and theequivalent Ro based on MPI-1 is 086 (Borehamet al 1988 Table 2) Tribe 6 and family 42 showsimilar bulk parameters including high sulfurcontent (~242 and 322 wt respectively) lowAPI gravity (~260deg and 259deg respectively)low saturatearomatic ratios (~080 and 052respectively) and low ltC15 fraction (~324 and304 respectively) Compared with the othersamples tribe 6 and family 42 also show elevatedDBTP (~055 and 071 respectively Table 2)Values of DBTP greater than 10 typify carbonatesource rocks (Hughes et al 1995) and we in-terpret the relatively high values for tribe 6 andfamily 42 to indicate clay-poor shale ormarl ratherthan typical shale lithology For tribe 6 and family42 elevated VNi (~075 and 180 respectively)and high sulfur content (242 and 384 wt re-spectively Table 2) compared with the other fam-ilies are consistent with more reducing conditionsduring source rock deposition andor lower thermalmaturity Based on a more positive CV (approxi-mately -094 Table 2) the source rock for tribe 6contained more terrigenous organic matter inputthan the source rocks for the other oil families

Tribe 6 shows lower C28C29 sterane ratios(~144) than the other oil families (~154ndash173Table 2) The C28C29 sterane ratio for marinepetroleum increased through geologic time due todiversification of phytoplankton assemblages in-cluding diatoms coccolithophores and dinofla-gellates in the Jurassic and Cretaceous (Moldowanet al 1985 Grantham and Wakefield 1988) TheC28C29 sterane ratio has been used to distinguishUpper Cretaceous andCenozoic oil from Paleozoicor older oil (Grantham and Wakefield 1988) Theauthors observed that theC28C29 sterane ratios forcrude oils frommarine source rocks with little or noterrigenous organic matter input are lt05 for lowerPaleozoicandolderoils 04ndash07 forupperPaleozoicto Lower Jurassic oils and greater than approxi-mately 07 for Upper Jurassic to Miocene oils ThelowC28C29 steraneand lowOlHratios for tribe6


(~144 and 0142 respectively Table 2) may in-dicate an older Miocene source rock than that forthe other oil families because these ratios areknown to have increased with diversification ofphytoplankton and angiosperms respectively(GranthamandWakefield1988Moldowanetal1994)

Stratigraphic Distribution

The stratigraphic position of oil samples in eachfamily provides circumstantial evidence as to theidentity of each familyrsquos source rock For examplethe vertical distribution of comparatively low-sulfur family 13 (tribe 1) and high-sulfur tribe 6oil samples along cross section AA9 (Figure 7)suggests that family13originated fromDelmontianblack shalenear the topof theorganic-richMiocenesection whereas tribe 6 originated from strati-graphically deeper anoxic distal shale or marl(lower Modelo nodular shale equivalent) Ourinterpretation is consistentwithearlierworkbasedonmainly sulfur content Based on bulk (eg APIgravity and sulfur content) and isotopic compo-sitions McCulloh et al (1993) concluded thatlow-sulfur crude oils near the eastern part of crosssectionAA9 (Figure1) originated from low-sulfurkerogen in mature Mohnian through Repettianshale located in the northernmost central troughJeffrey et al (1991) concluded that high-sulfur oil(gt2 wt ) near the western part of cross section

AA9 originated from the thermally mature lowerMohnian basal unit of the Modelo Formation(nodular shale equivalent)

Likewise the distributions of families 11 (tribe1)31and32(tribe3)andtribe5alongcrosssectionFF9 fromWright (1991) (Figure8) suggest that low-sulfur family 11 oil originated from Delmontianblack shale east of the NIFZ and that high-sulfurtribe 5 oil originated fromnodular shale in the basalPuenteFormationwestoftheNIFZFamilies31and32 occur at intermediate stratigraphic positionswest of the NIFZ corresponding to Mohnian andDelmontianunits respectivelyOur results expandupon earlier interpretations McCulloh et al(1993) concluded that low-sulfur oil near thewestern part of cross section FF9 (Figure 1) origi-nated from lower Mohnian Puente Formationsource rock in the central trough they also con-cluded that high-sulfur oil originated from thelower Mohnian basal unit of the Monterey-equivalent (nodular shale) on the southwesternshelf and migrated northeastward into traps to thewest to the NIFZ

Our results parallel those from coastalCalifornia (Peters et al 2008) and the San Joaquinbasin (Zumberge et al 2005 Peters et al 2013)where various genetically distinct Miocene oilfamilies retain the geochemical fingerprint ofthe vertical and lateral organofacies variations intheir source rocks and generally occur at similarstratigraphic levels Figure 9 summarizes the

Figure 7 Stratigraphic posi-tions of family 13 and tribe 6suggest upper Miocene (Del-montian) and middlendashupperMiocene (lower Modelo nodularshale equivalent) source rocksrespectively Section AA9 (seeFigure 1) modified from Wright(1991) and used with permissionof AAPG Structural features arethe following LCF = La Cienegasfault NIFZ = Newport-Inglewoodfault zone PVF = Palos Verdesfault Stratigraphic units are thefollowing Bc = undifferentiated

metamorphic basement D = Delmontian Mo =Mohnian (base is the contoured horizon in Figure 1) P = Pico Formation Q = QuaternaryR = Repetto Formation Tt = Topanga Formation Total horizontal length is approximately 4 mi (~64 km)

Peters et al 129

results in the context of regional stratigraphy of theLos Angeles basin Data from Kaplan et al(2000) indicate that the middlendashupper Miocenesection contains source rock due to high total or-ganic carbon (~4 wt ) and type IndashII oil-pronekerogen Earlier work shows that the shallowerPliocene and Pleistocene units in Figure 9 cannotbe source rock owing to low thermal maturity(Philippi 1965)

Inferred Source-Rock Intervals

Based on the above results the following interpre-tations can be made for the origins of the oil tribesAll of the oil tribes originated from different orga-nofacies within Miocene marine source rock thatreceived both phytoplankton and flowering-plantinput Tribes 1 and 2 originated from suboxic andproximal upperMiocene (Delmontian) shale in thecentral trough east of the NIFZ Tribe 2 is signifi-cantly more mature and the source rock was moreclay rich and received more angiosperm input thantribe 1 Anoxic and distal upper Miocene (middlendashupper Puente) shale source rock received lesshigher-plant input than tribes 1 and 2 and generatedtribe 3 oil to thewest of theNIFZ AnoxicMohnian()

clay-poor shale or marl generated tribe 4 oil to thewest of the NIFZ Higher-plant input was compa-rable to tribe 3 Anoxic and distal middlendashupperMiocene shale (lower Puente nodular shale) gener-ated tribe 5 oil to the southwest of the NIFZ Anoxicand distal middlendashupper Miocene (lower Modelonodular shale equivalent) clay-poor shale or marlgenerated tribe 6 northwest of the NIFZ at lowerlevels of thermal maturity than the other families

Example of Use of the Decision Tree

Some samples were excluded from the training setbecause either they were unavailable at that timeor theywere highlymature or heavily biodegradedThe chemometric decision tree (Figure 4) can beused for the genetic classification of such samplesprovided that their source-related biomarker andisotope parameters are not too heavily altered Theconfidence level calculated by the decision treeanalysis allows the interpreter to assess whethersamples have been too altered to allow reliable as-signment of genetic affinity As a test the same 24biomarker and stable isotope parameters used toconstruct the decision tree (Figure 4)were used topredict the genetic affiliations of 11 mildly to

Figure 8 Stratigraphic posi-tions of families 11 31 and 32and tribe 5 suggest upper Mio-cene (Delmontian) andmiddlendashupper Miocene (lowerPuente nodular shale) sourcerocks respectively Locations forsamples from families 31 and 32suggest source rocks at depthsbetween these two intervalsSection FF9 (see Figure 1) wasmodified fromWright (1991) andused with permission of AAPGStructural features are the fol-lowing AN = Anaheim noseNIFZ = Newport-Inglewood faultzone PVF = Palos Verdes faultWF =Whittier fault Stratigraphic units are the following Bc = undifferentiated metamorphic basement D = Delmontian K = CretaceousL = Luisian m = undifferentiated Delmontian-Mohnian Mo = Mohnian (base is the contoured horizon in Figure 1) P = Pico FormationPg = Paleogene R = Repetto Formation (u m l = upper middle lower) Tm =Monterey Formation Tt = Topanga Formation v = volcanicOne family 11 sample (Bel542 at 4954 ft [1510 m]) occurs west of the NIFZ at Belmont Offshore Total horizontal length is approximately58 mi (~93 km)


heavily biodegraded oil samples from the LosAngeles basin (Table 3) For one sample in whichthe sterane ratios were clearly altered (Saw481biodegradation rank = 6) mean fill values weresubstituted foreachsteraneparameterSteranes incrudeoil having rank6or higher have beenheavilybiodegraded (Figure2)which thus limits their use

for oilndashoil correlation Samples having more thanfour altered biomarker parameters owing to ex-treme biodegradation cannot be reliably classifiedThe map locations and predicted family for each ofthe 11 samples (Table 3) are consistent with the loca-tions of other samples in those families suggestingthat these assignments are geologically reasonable

Figure 9 Stratigraphic occur-rence can be used to infer thesource rock for oil families 5 611 13 31 and 32 in the LosAngeles basin (stratigraphymodified from Blake 1991) SeeFigures 1 7 and 8 for locations ofstratigraphic sections Symbolsfor oil families are consistentamong these figures TheModelo Formation is MohnianndashDelmontian (~138ndash45 MaWright 1991) brown-tondashbrownishgray diatomaceous shale withinterbedded sandstone Thephosphatic nodular shale in thePuente Formation contains upto 10 wt total organic carbon(TOC) (Walker et al 1983)Marine

slightly reducing Monterey-equivalent shale (MohnianndashDelmontian Puente Formation) contains 2ndash18 wt TOC with an average of 4 wt deposited under marine anoxic conditions based on a compilation of data from Global Geochemistry Corporation (Kaplan et al 2000) andrepresents amajor source-rock interval (Philippi 1965) The baseMohnian (bold) is the contouredhorizon in Figure 1 NIFZ=Newport-Inglewoodfault zone Topg Cyn = Topanga Canyon Topanga Gp = Topanga Group [Topanga Canyon Conejo Volcanics and Calabasas formations]Vol Sd = volcanic-rich sandstone

Table 3 Location Depth Biodegradation Rank (Peters andMoldowan 1993) Predicted Family and Confidence in Family Assignment for11 Mildly to Heavily Biodegraded Oil Samples from the Los Angeles Basin California

Sample Longitude Latitude Depth ft (m) Rank Family Confidence

Saw481 -1184555 340586 mdash 6 6 0814Wil78 -1182464 3378629 mdash 5 41 0987Wil85 -1182361 337863 mdash 5 41 0935HB462 -118044 336626 1600 (488) 5 32 0923Wil531 -1181796 337594 3894 (1187) 5 41 0958Wil532 -1181625 337406 4896 (1492) 5 41 0985Wil533 -1181624 337413 5500 (1676) 5 41 0992Wil536 -1181942 337524 4663 (1421) 5 41 0960Wil592 -1181577 337532 mdash 5 41 0989LB6 -1181896 338238 mdash 4 5 0971LB506 -1181694 338056 2982 (909) 1 33 0969

The family for each sample was assigned using the chemometric decision tree (Figure 4) Confidence level was calculated based on a probability cutoff (eg if the probabilitycutoff for family membership is 099 then 99 of the samples will be properly predicted)

Peters et al 131

CONCLUSIONS

Chemometric analysis of 24 source-related bio-marker and stable carbon isotope ratios for 111non- or mildly biodegraded oil samples identifiessix genetically distinct Miocene tribes (12 families)in the Los Angeles basin These families occur indifferent parts of the basin and exhibit differentbulk properties such as API gravity and sulfurcontent which were strongly influenced by sec-ondary processes such as thermal maturity orbiodegradation However biomarker and isotopecompositions resist secondary processes and areprincipally controlled by the organic matter inputand depositional environment of the source rock

Stable carbon isotope data for saturate andaromatic fractions of the samples are consistentwith Miocene source rocks deposited in a marinesettingMost oil samples in tribes 1 and 2 occur tothe east of the NIFZ (families 11ndash13 and 21ndash22)and tribes 3ndash6 (families 31ndash33 41ndash42 5 and 6)occur to the west of the NIFZ Biomarker andisotope ratios and distinct stratigraphic occur-rence for the oil samples help to identify thesource rock organofacies for each oil family Aspreviously observed forMiocene oil samples fromthe San Joaquin basin in California oil samplesfrom theLosAngeles basin retain the geochemicalfingerprint of the vertical and lateral organofaciesvariations within their specific Miocene sourcerocks Tribes 1 and 2 originated from proximal shalesource rock in the central trough that was depositedunder suboxic conditions with elevated siliciclasticand higher-plant input Tribes 3ndash6 originated fromdistal shale or marl organofacies to the west of theNIFZ that were deposited under generally morereducing to anoxic conditions

The results of this studydemonstrate thepowerof combined biomarker isotope and chemometricanalysis to improve understanding of variations incrude oil composition that result from differ-ing organofacies within a single source rockHierarchical cluster analysis and principal com-ponent analysis allowed the definitive classificationof 111non- ormildly biodegradedoil samples fromthe study areaThe resulting familieswereused as atraining set to construct a chemometric decision

tree that can be used to assign (1) genetic affinitiesand (2) a level of confidence in the classification forany additional samples of crude oil or source-rockextract that become available Many oil samplesfrom the Los Angeles basin that have undergonesignificant alteration by secondary processes stillcan be reliably classified using the chemometricdecision tree as long as most of the selected bio-marker and isotope parameters remain unaltered

APPENDIX

The parameters used for the chemometric analysis include16 terpane 5 sterane and 3 stable carbon isotope ratiosComplete data are available by subscription from GeoMarkResearch Ltd (2015) Terpane ratios includeC19C23 C22C21 C24C23 and C26C25 tricyclic terpanes C26Ts C24

tetracyclic terpaneC23 tricyclic terpane (TetC23) C27

tetracyclic terpaneC27 tricyclic terpane (C27TC27) 2830-bisnorhopanehopane (BNHH) C29 30-norhopanehopane(C29H) C30 diahopanehopane (XH) oleananehopane(OlH) C31 homohopane 22Rhopane (C31RH) gammaceraneC31 homohopane 22R (GaC31R) C35 homohopane 22SC34

homohopane 22S (C35SC34S) C27 18a-trisnorneohopane17a-trisnorhopane (C27TsTm) andC2918a30-norneohopane17a30-norhopane (C29 TsTm) The sterane ratios includesteraneshopanes (SH) C27 C28 and C29 steranes(eg C27 = C27[C27 to C29] based on 5a14band17b steranes from mz 218) and the diasterane ratio(S1S6) The SH ratio consists of 15 sterane peaks frommz 217 (13b17a diacholestane 20S 13b17a diacholestane20R 5a cholestane 20S + 5b cholestane 20R 5a14b17bcholestane 20R + 13b 17a diastigmastane 20S 5a14b17bcholestane 20S 5a cholestane 20R diastigmastane 5aergostane 20S 5a14b17b ergostane 20R + 5b ergostane20R 5a14b17b ergostane 20S 5a ergostane 20R 5astigmastane 20S 5a14b17b stigmastane 20R 5a14b17bstigmastane 20S + 5b stigmastane 20R and 5a stigmastane20R) divided by 16 hopane peaks from mz 191 (C27 Ts andTm 2830-bisnorhopane C29 Ts and Tm hopane and C31 toC35 22S and 22R hopanes) The S1S6 ratio consists of 13b17a diacholestane 20S5a cholestane 20R The stable carbonisotope ratios include d13Csaturate d

13Caromatic and the ca-nonical variable (CV) where CV = -253 d13Csaturate + 222d13Caromatic - 1165 (Sofer 1984) Many of these parametersare discussed in Peters et al (2005)

REFERENCES CITED

Andrusevich V E M H Engel J E Zumberge andL A Brothers 1998 Secular episodic changes in stablecarbon isotope composition of crude oils Chemical


Geology v 152 p 59ndash72 doi101016S0009-2541(98)00096-5

BarbatW F 1958 The Los Angeles basin area California inL G Weeks ed Habitat of oilmdashA symposium AAPGp 62ndash77

Baskin D K and K E Peters 1992 Early generation char-acteristics of a sulfur-rich Monterey kerogen AAPGBulletin v 76 no 1 p 1ndash13

Beyer L A 1988 Summary of geology and petroleum playsused to assess undiscovered recoverable petroleum re-sources of Los Angeles basin province California USGeological Survey Open-File Report 88ndash450L 62 p

Beyer L A and J A Bartow 1987 Summary of geologyand petroleum plays used to assess undiscovered re-coverable petroleum resource San Joaquin basin prov-ince California US Geological Survey Open-File Report87ndash450Z 80 p

Biddle K T 1991 The Los Angeles basinmdashan overview inK T Biddle ed Active margin basins AAPG Memoir52 p 5ndash24

Blake G H 1991 Review of the Neogene biostratigraphyand stratigraphy of theLosAngeles basin and implicationsfor basin evolution in K T Biddle ed Active marginbasins AAPG Memoir 52 p 135ndash184

BorehamC J IHCrick andTGPowell 1988Alternativecalibration of the Methylphenanthrene Index againstvitrinite reflectance Application to maturity measure-ments on oils and sediments Organic Geochemistryv 12 p 289ndash294 doi1010160146-6380(88)90266-5

Brown J B 1968 Gas in Los Angeles basin California inBW Beebe ed Natural gases of NorthAmerica AAPGMemoir 9 p 149ndash163

California Department of Conservation 2010 2009 annualreport of the state oil and gas supervisor (E M MillerSupervisor) Division of Oil Gas and Geothermal Re-sources accessed April 10 2015 wwwconservationcagovDOGpubs_statsannual_reportsannual_reportshtm

Campbell R H and R F Yerkes 1976 Cenozoic evolutionof the Los Angeles basin areamdashrelation to plate tectonicsinDGHowell ed Aspects of the geologic history of theCaliforniaContinental Borderland Pacific SectionAAPGMiscellaneous Publication 24 p 541ndash558

ChungHMMA RooneyM B Toon andG E Claypool1992 Carbon isotope composition of marine crude oilsAAPG Bulletin v 76 no 7 p 1000ndash1007

Clark J P and R P Philp 1989 Geochemical character-ization of evaporite and carbonate depositional environ-ments and correlation of associated crude oils in the BlackCreek basin Alberta Bulletin of Canadian PetroleumGeology v 37 p 401ndash416

Crowell J C 1974 Origin of the late Cenozoic basins insouthern California in W R Dickinson ed Tectonicsand sedimentation SEPM Special Publication 22p 190ndash204 doi102110pec74220190

Curiale J A D Cameron and D V Davis 1985 Biologicalmarker distribution and significance in oils and rocksof the Monterey Formation California Geochimica etCosmochimica Acta v 49 p 271ndash288 doi1010160016-7037(85)90210-8

Demaison G J and G T Moore 1980 Anoxic environ-ments and oil source bed genesis AAPG Bulletin v 64no 8 p 1179ndash1209

Driver H L 1948 Genesis and evolution of the Los Angelesbasin California AAPGBulletin v 32 no 1 p 109ndash125

Edwards E C 1951 Los Angeles region AAPG Bulletinv 35 no 2 p 241ndash248

Freeman S T E G Heath P D Guptilli andJ T Waggoner 1992 Seismic hazard assessmentNewport-Inglewood fault zone in B W Pipkin andR J Proctor eds Engineering geology practice insouthern California Belmont California Associationof Engineering Geologists Special Publication 4p 211ndash229

Gardett P H 1971 Petroleum potential of the Los Angelesbasin in I H Cram ed Future petroleum provinces ofthe United StatesmdashTheir geology and potential AAPGMemoir 15 p 298ndash308

GeoMark Research Ltd 2015 Global oil geochemical da-tabase accessed April 10 2015 httpsrfdbasegeo-markresearchcom

Grantham P J and L L Wakefield 1988 Variations in thesterane carbon number distributions of marine sourcerock derived crude oils through geological time OrganicGeochemistry v 12 p 61ndash73 doi1010160146-6380(88)90115-5

Harding T P 1973 Newport-Inglewood trend CaliforniamdashAn example of wrenching style of deformation AAPGBulletin v 57 no 1 p 97ndash116

Hill M L 1971 Newport-Inglewood zone and Mesozoicsubduction California Geological Society of AmericaBulletin v 82 no 10 p 2957ndash2962 doi1011300016-7606(1971)82[2957NZAMSC]20CO2

Hornafius J S 1991 Facies analysis of the Monterey For-mation in the northern Santa Barbara Channel AAPGBulletin v 75 no 5 p 894ndash909

HughesWBAGHolba andL I PDzou1995The ratiosof dibenzothiophene to phenanthrene and pristane tophytane as indicators of depositional environment andlithology of petroleum source rocks Geochimica etCosmochimica Acta v 59 p 3581ndash3598 doi1010160016-7037(95)00225-O

Ingersoll R V 2008 Reconstructing southern Californiain J E Spencer and S R Titley eds Ores and orogenesisCircum-pacific tectonics geologic evolution and oredeposits Arizona Geological Society Digest 22p 409ndash417

Ingersoll R V and P E Rumelhart 1999 Three-stageevolution of the Los Angeles basin southern CaliforniaGeology v 27 p 593ndash596 doi1011300091-7613(1999)027lt0593TSEOTLgt23CO2

Isaacs C M 2001 Depositional framework of the MontereyFormation California in C M Isaacs and J Rullkottereds The Monterey Formation From rocks to moleculesNew York Columbia University Press p 1ndash30

Jeffrey A W A H M Alimi and P D Jenden 1991Geochemistry of Los Angeles basin oil and gas systems inK T Biddle ed Active margin basins AAPG Memoir52 p 197ndash219

Peters et al 133

Jones R W 1987 Organic facies in J Brooks and DWelteeds Advances in petroleum geochemistry New YorkAcademic Press p 1ndash90

Kaplan I R M H Alimi C Hein A Jeffrey M R LaffertyM P Mankiewicz D E Meredith E B Edwards andW S Dixon 2000 The geochemistry of hydrocarbonsand potential source rocks from the Los Angeles andVentura basins data synthesis and text in I R Kaplaned Collection of papers about the oil gas and source rockgeochemical investigations carried out in the San JoaquinSanta Maria Santa Barbara Ventura and Los AngelesbasinsCalifornia Pacific SectionAAPGCD-ROMSeries1 p 1ndash238

Katz B J and L W Elrod 1983 Organic geochemistry ofDSDP Site 467 offshore California Middle Miocene toLower Pliocene strata Geochimica et CosmochimicaActa v 47 p 389ndash396 doi1010160016-7037(83)90261-2

LewanMD 1984 Factors controlling the proportionality ofvanadium to nickel in crude oils Geochimica et Cos-mochimica Acta v 48 p 2231ndash2238 doi1010160016-7037(84)90219-9

Mackenzie A S C F Hoffmann and J R Maxwell 1981Molecular parameters of maturation in the Toarcianshales Paris basin France ndash III Changes in the aromaticsteroid hydrocarbons Geochimica et CosmochimicaActa v 45 p 1345ndash1355 doi1010160016-7037(81)90227-1

Mayer L 1987 Subsidence analysis of the Los Angeles basinin R V Ingersoll and W G Ernst eds Cenozoic basindevelopment of coastal California Englewood CliffsNew Jersey Prentice-Hall p 299ndash320

Mayer L 1991 Central Los Angeles basin subsidenceand thermal implications for tectonic evolution inK T Biddle ed Active margin basins AAPG Memoir52 p 185ndash195

McCulloh T H D W Kirkland A J Koch W L Orr andH M Chung 1994 How oil composition relates tokerogen facies in the worldrsquos most petroliferous basinAAPG Search and Discovery article 90986 accessedOctober 27 2015 httpwwwsearchanddiscoverycomabstractshtml1994annualabstracts0210bhtm

McCulloh T H W L Orr D W Kirkland A J Koch andH M Chung 1993 Oils and source rocks of thesouthwestern Los Angeles basin Multiple sources anddifferent organic facies (abs) AAPG Pacific SectionMeeting Long Beach California May 5ndash7 accessedOctober 27 2015 httpwwwsearchanddiscoverycomabstractshtml1993pacificabstracts0707chtm

McKirdy D M A K Aldridge and P J M Ypma 1983 Ageochemical comparison of some crude oils from Pre-Ordovician carbonate rocks in M Bjoroslashy C AlbrechtC Cornford K de Groot E Eglinton E GalimovD Leythaeuser R Pelet J Rullkotter andG Speer edsAdvances in organic geochemistry 1981 NewYork JohnWiley and Sons p 99ndash107

Moldowan J M J Dahl B J Huizinga F J FagoL JHickeyTMPeakman andDWTaylor 1994Themolecular fossil record of oleanane and its relation to

angiosperms Science v 265 p 768ndash771 doi101126science2655173768

Moldowan J M W K Seifert and E J Gallegos 1985Relationship between petroleum composition and de-positional environment of petroleumsource rocksAAPGBulletin v 69 no 8 p 1255ndash1268

Nicholson C C C Sorlien T Atwater J C Crowell andB P Luyendyk 1994Microplate capture rotation of thewestern Transverse Ranges and initiation of the SanAndreas transform as a low-angle fault system Geologyv 22 p 491ndash495 doi1011300091-7613(1994)022lt0491MCROTWgt23CO2

Orr W L 1986 Kerogenasphaltenesulfur relationshipsin sulfur-richMonterey oils Organic Geochemistry v 10p 499ndash516 doi1010160146-6380(86)90049-5

Peters K E and J M Moldowan 1991 Effects of sourcethermal maturity and biodegradation on the distributionand isomerization of homohopanes in petroleum Or-ganic Geochemistry v 17 p 47ndash61 doi1010160146-6380(91)90039-M

Peters K E and J M Moldowan 1993 The biomarkerguidemdashInterpreting molecular fossils in petroleum andancientsedimentsEnglewoodCliffsNewJerseyPrentice-Hall 363 p

Peters K E D Coutrot X Nouvelle L S RamosBG Rohrback L BMagoon and J E Zumberge 2013Chemometric differentiation of crude oil families in theSan JoaquinbasinCaliforniaAAPGBulletin v 97no 1p 103ndash143 doi10130605231212018

Peters K E T D Elam M H Pytte and P Sundararaman1994 Identification of petroleum systems adjacent to theSan Andreas Fault California USA in L B Magoonand W G Dow eds The petroleum systemmdashFromsource to trap AAPG Memoir 60 p 423ndash436

Peters K E F D Hostettler T D Lorenson andR J Rosenbauer 2008 Families of Miocene Montereycrude oil seep and tarball samples coastal CaliforniaAAPG Bulletin v 92 no 9 p 1131ndash1152 doi10130604180807113

Peters K E L S Ramos J E Zumberge Z C ValinC R Scotese and D L Gautier 2007 Circum-Arcticpetroleum systems identified using decision-treechemometrics AAPG Bulletin v 91 no 6 p 877ndash913doi10130612290606097

Peters K E C C Walters and J M Moldowan 2005 Thebiomarker guide Cambridge UK Cambridge UniversityPress 1155 p

Philippi G T 1965 On the depth time and mechanism ofpetroleum generation Geochimica et CosmochimicaActa v 29 p 1021ndash1049 doi1010160016-7037(65)90101-8

Pisciotto K A and R E Garrison 1981 Lithofacies and de-positional environments of the Monterey Formation inR E Garrison and R G Douglas eds The Montereyformation and related siliceous rocks of California PacificSection SEPM Book 15 p 97ndash122

Price L C 1994 Basin richness versus source rock disruptionfrom faultingmdashA fundamental relationship Journal of


Petroleum Geology v 17 p 5ndash38 doi101111j1747-54571994tb00112x

Price L C M Pawlewicz and T Daws 1999 Organicmetamorphism in the California petroleum basinsChapter AmdashRock-Eval and vitrinite reflectance USGeological Survey Bulletin 2174 34 p

Radke M D H Welte and H Willsch 1982 Geochemicalstudy on a well in the Western Canada basin Relation ofthe aromatic distribution pattern to maturity of organicmatter Geochimica et Cosmochimica Acta v 46p 1ndash10 doi1010160016-7037(82)90285-X

RedinT 1991Oil andgasproduction fromsubmarine fans ofthe Los Angeles basin in K T Biddle ed Active marginbasins AAPG Memoir 52 p 239ndash259

Schwartz D E and I P Colburn 1987 Late Tertiary torecent chronology of the Los Angeles basin southernCalifornia in P J Fischer ed Geology of the PalosVerdes Peninsula and San Pedro Bay Pacific SectionSEPM Book 55 p 5ndash16

Sofer Z 1984 Stable carbon isotope compositions of crudeoils Application to source depositional environments andpetroleum alteration AAPG Bulletin v 68 no 1p 31ndash49

Walker A L T H McCulloh N F Petersen andR J Stewart 1983 Anomalously low reflectance ofvitrinite in comparison with other petroleum source-rockmaturation indices from the Miocene Modelo Formationin the Los Angeles basin California in C M Isaacs andREGarrison eds Petroleumgeneration andoccurrence

in the Miocene Monterey Formation California PacificSection SEPM Book 33 p 185ndash190

Woodford A O J E Schoellhamer J G Vedder andR F Yerkes 1954 Geology of the Los Angeles basin(California) Geology of Southern California CaliforniaDivision ofMines andGeology Bulletin v 170 p 65ndash81

Wright T 1987 Geologic summary of the LosAngeles basinin T Wright and R Heck eds Petroleum geology ofcoastal southern California AAPG Pacific SectionGuidebook 60 p 21ndash31

Wright T L 1991 Structural geology and tectonic evolutionof the Los Angeles basin California AAPG Memoir 52p 35ndash134

Yeats R S 1973 Newport-Inglewood fault zone LosAngeles basin California AAPG Bulletin v 57 no 1p 117ndash136

Yerkes R F T H McCulloh J E Schoellhamer andJ G Vedder 1965 Geology of the Los Angeles basinCaliforniamdashAn introduction US Geological SurveyProfessional Paper 420ndashA p A1ndash57

Zumberge J E 1987 Prediction of source rock characteristicsbased on terpane biomarkers in crude oils A multivariatestatistical approach Geochimica et CosmochimicaActa v 51 p 1625ndash1637 doi1010160016-7037(87)90343-7

Zumberge J E J A Russell and J A Reid 2005 ChargingtheElkHills reservoirs as determinedby oil geochemistryAAPG Bulletin v 89 no 10 p 1347ndash1371 doi10130605100504003

Peters et al 135

Geochemistry and stratigraphy of the oil tribes (1ndash6 below)suggest the following source-rock organofacies

1 Suboxic upper Miocene (Delmontian) proximal clay-richshale generated low-sulfur tribe 1 and 2 oil types(~055ndash106 wt ) east of the NIFZ that show higherthermalmaturity than tribes 3ndash6The source rock for tribe 1was slightly more reducing (lower redox potential or Eh)than that for tribe 2

2 Low-sulfur tribe 2 oil (~020ndash023 wt ) is significantlymore mature and the source rock is more clay rich andreceived more angiosperm input than tribe 1

3 Anoxic upper Miocene (middlendashupper Puente) distal shalesource rock generated sulfur-rich tribe 3 oil (~142ndash158wt ) west of the NIFZ The source rock received lesshigher-plant input than the source rocks for tribes 1 and 2

4 Suboxicndashanoxic Mohnian() clay-poor shale or marl sourcerock generated tribe 4 oil west of theNIFZOneoil family intribe 4 has low sulfur whereas the other has high sulfurcontent Higher-plant input is comparable to tribe 3

5 Anoxic middlendashupper Miocene (Lower Puente ldquonodularshalerdquo) distal shale generated sulfur-rich (~124 wt ) tribe5 oil to the southwest of the NIFZ

6 Anoxic middlendashupper Miocene (Lower Modelo nodularshale equivalent) distal shale or marl generated high-sulfurtribe 6 oil (~242 wt ) to the northwest of the NIFZ atlower levels of thermal maturity than the other tribes

INTRODUCTION

The Los Angeles basin (Figure 1) has been described as therichest petroliferous basin in the world based on the amount ofpetroleum relative to the volume of sedimentary fill (Barbat1958 Yerkes et al 1965 Wright 1987 Price 1994 Priceet al 1999) Since the discovery of the Brea-Olinda field in1880 (Biddle 1991 B-Ol in Figure 1) about 67 additionalfields have been discovered including 3 of the 10 largest fieldsin California at Wilmington (1932 298 billion barrels of oil[bbo]) Huntington Beach (1920 116 bbo) and Long Beach(095 bbo California Department of Conservation 2010Table1) Supergiant oilfields contain at least 1bboof estimatedultimate recoverable petroleumGeologically the LosAngelesbasin is among the most thoroughly studied and exploredbasins in the world (eg Driver 1948 Edwards 1951Woodford et al 1954 Barbat 1958 Yerkes et al 1965Brown 1968Gardett 1971Hill 1971Harding 1973 Yeats

was a founding member (1970) of the AAPGEnvironmental Geology Committee (Chair1974ndash1977) and the Division of EnvironmentalGeology (1992) He received the Michel THalbouty Human Needs Award in 2000 forefforts to introduce data and insights fromsubsurface petroleum geology into ongoingstudies of earthquake hazards in the LosAngeles region Tom received the AAPGDistinguished Service Award in 1993 and he isan Honorary Member of the Pacific Section(1989)He has BS andMS degrees in geologyfrom Stanford University

L S Ramos ~ Infometrix Inc 11807 NorthCreek Parkway South Suite B-111 BothellWashington 98011 scott_ramosinfometrixcom

L Scott Ramos has a PhD in analyticalchemistry and chemometrics from theUniversity of Washington Scott worked at theNational Oceanographic and AtmosphericAdministration National Marine FisheriesService in Seattle the State Pollution ControlAgency in Rio de Janeiro Brazil and the FederalAmazon Research Institute in Manaus BrazilHehasworkedfor Infometrix Inc formorethan30 years His publications include studies ofcontamination by polycyclic aromatichydrocarbons essential oil characterizationand chemometrics

J E Zumberge ~ GeoMark Research Ltd9748 Whithorn Drive Houston Texas 77095jzumbergegeomarkresearchcom

John E Zumberge has a PhD in organicgeochemistry from the University of Arizonaand is the senior vice president (since 1991) ofGeoMark Research which he cofounded in1991 John was manager of geochemical andgeological research for CitiesServicendashOccidental generalmanager for RuskaLaboratories and director of geochemicalservices for Core Laboratories He has globalexperience in petroleum geochemistryfocusing on crude oil biomarkers

L B Magoon ~ Department of Geologicaland Environmental Sciences StanfordUniversity 450 Serra Mall StanfordCalifornia 94305 lmagoonstanfordedu

Leslie B Magoon is currently consultingprofessor in the Basin and Petroleum SystemModeling Industrial Affiliates Program at




REGIONAL GEOLOGY



ACKNOWLEDGMENTS


Peters et al 117












Peters et al 119













METHODS

Laboratory Analyses


Sample Screening


Peters et al 121















Peters et al 123










Table2


Biom


LosAngelesBasin

OilFamilie

s

Family

Number

ofSamples

BulkPropertiesforNo

nbiodegraded

Samples

Maturity

Shale

Carbonate

Redox

Terrigenous

Angiosperm

s

APIG

ravity

Sulfurwt

Saturates

Arom

atics

ltC

15Fraction

MPI-1

R oEq

TAS3(CR)

TsTm

C 24C 2

3C 2

9H

DBTP

C 35C 3

4SBN

HH

VNi

CVC 2

8C 2

9St

C 19C 2

3OlH

116

282ndash59(5)

100

ndash006

(4)

125

ndash013

(5)

399ndash38(5)

108

ndash018

098

ndash013

012

ndash002

050

ndash003

077

ndash005

049

ndash001

018

ndash009

081

ndash008

017

ndash008

070

ndash023

(4)-

160

ndash032

173

ndash004

0016ndash00030143ndash0017

128

326ndash20(6)

055

ndash000

(1)

133

ndash008

(6)

474ndash45(6)

112

ndash016

100

ndash011

014

ndash005

055

ndash004

086

ndash003

046

ndash002

018

ndash015

071

ndash003

018

ndash001

036

ndash048

(3)-

162

ndash012

169

ndash005

0023ndash00020219ndash0012

1319

302ndash45(13)

106

ndash091

(7)

131

ndash021

(15)

442ndash56(15)

113

ndash014

101

ndash010

016

ndash005

063

ndash009

094

ndash008

045

ndash002

021

ndash013

076

ndash009

021

ndash004

000

ndash000

(7)-

189

ndash051

160

ndash007

0035ndash00140260ndash0067

215

353ndash45(5)

020

ndash001

(3)

189

ndash021

(5)

589ndash65(5)

149

ndash019

126

ndash013

019

ndash004

083

ndash022

088

ndash005

042

ndash003

005

ndash005

064

ndash009

021

ndash008

000

ndash000

(3)-

204

ndash029

161

ndash003

0047ndash00080516ndash0115

226

326ndash21(6)

023

ndash012

(6)

157

ndash013

(6)

554ndash51(6)

139

ndash008

119

ndash005

021

ndash003

059

ndash004

090

ndash003

043

ndash001

007

ndash001

061

ndash003

015

ndash002

000

ndash000

(5)-

174

ndash042

170

ndash002

0029ndash00030298ndash0014

318

235ndash00(1)

142

ndash044

(2)

091

ndash004

(2)

301ndash69(2)

099

ndash010

092

ndash007

008

ndash001

042

ndash004

074

ndash004

054

ndash003

032

ndash011

087

ndash006

032

ndash008

045

ndash015

(4)-

188

ndash043

166

ndash004

0016ndash00040131ndash0020

325

mdashmdash

mdashmdash

104

ndash008

095

ndash006

007

ndash001

042

ndash002

072

ndash004

056

ndash001

025

ndash007

088

ndash002

034

ndash002

041

ndash003

(3)-

240

ndash019

158

ndash003

0019ndash00020140ndash0008

3315

mdash158

ndash000

(1)

098

ndash000

(1)

202ndash00(1)

113

ndash015

101

ndash010

006

ndash001

034

ndash001

070

ndash005

057

ndash002

033

ndash011

089

ndash007

028

ndash001

070

ndash000

(1)-

213

ndash019

165

ndash003

0013ndash00020116ndash0018

418

268ndash00(1)

057

ndash000

(1)

090

ndash000

(1)

423ndash00(1)

107

ndash018

097

ndash012

008

ndash004

041

ndash007

085

ndash006

057

ndash007

030

ndash010

095

ndash005

032

ndash005

026

ndash029

(5)-

263

ndash050

158

ndash003

0016ndash00020141ndash0017

427

259ndash87(4)

322

ndash062

(2)

052

ndash008

(7)

304ndash54(7)

103

ndash010

095

ndash007

009

ndash001

043

ndash002

099

ndash009

051

ndash003

071

ndash019

096

ndash011

026

ndash009

180

ndash032

(2)-

148

ndash059

164

ndash009

0017ndash00050139ndash0016

510

308ndash21(3)

124

ndash098

(3)

105

ndash042

(5)

453ndash221(5)102

ndash017

093

ndash012

008

ndash005

042

ndash014

074

ndash006

054

ndash004

025

ndash016083

ndash010

055

ndash032

013

ndash026

(4)-

152

ndash031

154

ndash009

0030ndash00090171ndash0022

614

260ndash65(7)

242

ndash034

(7)

080

ndash023

(12)

324ndash97(12)

086

ndash011

082

ndash008

007

ndash002

044

ndash005

080

ndash003

054

ndash002

055

ndash021

088

ndash013

032

ndash010

075

ndash074

(8)-

094

ndash024

144

ndash007

0024ndash00050142ndash0016




wport-Inglew




samples

(biodegradationrank

=0on

theP

etersand

Moldowan

[1993]scale)wereu

sedforaverage




(num



DBTPandVNi

ratioswerenotu

sedinthechem

ometric

analysis

AbbreviationsBNH


9C 2

3=C 1

9C 2


4C 2

3=C 2

4tetracyclicC 2


005)C

28C

29St=C 2

8C 2

9ste

ranes


9H=C 2

930-norhopaneC

30hopane


35SC 3

4S=C 3

5homohopane22SC 3



aturate+222

d13C a


etal1982)O

lH=oleananeC

30hopane

(Moldowan

etal

1994)R o

Eq=

equivalentvitrinite

reflectance(Boreham

etal1

988)TAS3(CR)=

(C20+C 2

1)(C 2

0+C 2

1+C 2

6+C 2

7+C 2

8)triarom


atogram[also

calledTA(I)TA(I+

II)asm

odified

fromMackenzieetal

(1981)

byPetersetal(2005)]

TsTm

=C 2



=vanadium

nickel(Lew

an1984)

Peters et al 125














Peters et al 127

















Peters et al 129

















Peters et al 131

CONCLUSIONS





APPENDIX






REFERENCES CITED

































Peters et al 133










































Peters et al 135



REGIONAL GEOLOGY



ACKNOWLEDGMENTS


Peters et al 117












Peters et al 119













METHODS

Laboratory Analyses


Sample Screening


Peters et al 121















Peters et al 123










Table2


Biom


LosAngelesBasin

OilFamilie

s

Family

Number

ofSamples

BulkPropertiesforNo

nbiodegraded

Samples

Maturity

Shale

Carbonate

Redox

Terrigenous

Angiosperm

s

APIG

ravity

Sulfurwt

Saturates

Arom

atics

ltC

15Fraction

MPI-1

R oEq

TAS3(CR)

TsTm

C 24C 2

3C 2

9H

DBTP

C 35C 3

4SBN

HH

VNi

CVC 2

8C 2

9St

C 19C 2

3OlH

116

282ndash59(5)

100

ndash006

(4)

125

ndash013

(5)

399ndash38(5)

108

ndash018

098

ndash013

012

ndash002

050

ndash003

077

ndash005

049

ndash001

018

ndash009

081

ndash008

017

ndash008

070

ndash023

(4)-

160

ndash032

173

ndash004

0016ndash00030143ndash0017

128

326ndash20(6)

055

ndash000

(1)

133

ndash008

(6)

474ndash45(6)

112

ndash016

100

ndash011

014

ndash005

055

ndash004

086

ndash003

046

ndash002

018

ndash015

071

ndash003

018

ndash001

036

ndash048

(3)-

162

ndash012

169

ndash005

0023ndash00020219ndash0012

1319

302ndash45(13)

106

ndash091

(7)

131

ndash021

(15)

442ndash56(15)

113

ndash014

101

ndash010

016

ndash005

063

ndash009

094

ndash008

045

ndash002

021

ndash013

076

ndash009

021

ndash004

000

ndash000

(7)-

189

ndash051

160

ndash007

0035ndash00140260ndash0067

215

353ndash45(5)

020

ndash001

(3)

189

ndash021

(5)

589ndash65(5)

149

ndash019

126

ndash013

019

ndash004

083

ndash022

088

ndash005

042

ndash003

005

ndash005

064

ndash009

021

ndash008

000

ndash000

(3)-

204

ndash029

161

ndash003

0047ndash00080516ndash0115

226

326ndash21(6)

023

ndash012

(6)

157

ndash013

(6)

554ndash51(6)

139

ndash008

119

ndash005

021

ndash003

059

ndash004

090

ndash003

043

ndash001

007

ndash001

061

ndash003

015

ndash002

000

ndash000

(5)-

174

ndash042

170

ndash002

0029ndash00030298ndash0014

318

235ndash00(1)

142

ndash044

(2)

091

ndash004

(2)

301ndash69(2)

099

ndash010

092

ndash007

008

ndash001

042

ndash004

074

ndash004

054

ndash003

032

ndash011

087

ndash006

032

ndash008

045

ndash015

(4)-

188

ndash043

166

ndash004

0016ndash00040131ndash0020

325

mdashmdash

mdashmdash

104

ndash008

095

ndash006

007

ndash001

042

ndash002

072

ndash004

056

ndash001

025

ndash007

088

ndash002

034

ndash002

041

ndash003

(3)-

240

ndash019

158

ndash003

0019ndash00020140ndash0008

3315

mdash158

ndash000

(1)

098

ndash000

(1)

202ndash00(1)

113

ndash015

101

ndash010

006

ndash001

034

ndash001

070

ndash005

057

ndash002

033

ndash011

089

ndash007

028

ndash001

070

ndash000

(1)-

213

ndash019

165

ndash003

0013ndash00020116ndash0018

418

268ndash00(1)

057

ndash000

(1)

090

ndash000

(1)

423ndash00(1)

107

ndash018

097

ndash012

008

ndash004

041

ndash007

085

ndash006

057

ndash007

030

ndash010

095

ndash005

032

ndash005

026

ndash029

(5)-

263

ndash050

158

ndash003

0016ndash00020141ndash0017

427

259ndash87(4)

322

ndash062

(2)

052

ndash008

(7)

304ndash54(7)

103

ndash010

095

ndash007

009

ndash001

043

ndash002

099

ndash009

051

ndash003

071

ndash019

096

ndash011

026

ndash009

180

ndash032

(2)-

148

ndash059

164

ndash009

0017ndash00050139ndash0016

510

308ndash21(3)

124

ndash098

(3)

105

ndash042

(5)

453ndash221(5)102

ndash017

093

ndash012

008

ndash005

042

ndash014

074

ndash006

054

ndash004

025

ndash016083

ndash010

055

ndash032

013

ndash026

(4)-

152

ndash031

154

ndash009

0030ndash00090171ndash0022

614

260ndash65(7)

242

ndash034

(7)

080

ndash023

(12)

324ndash97(12)

086

ndash011

082

ndash008

007

ndash002

044

ndash005

080

ndash003

054

ndash002

055

ndash021

088

ndash013

032

ndash010

075

ndash074

(8)-

094

ndash024

144

ndash007

0024ndash00050142ndash0016




wport-Inglew




samples

(biodegradationrank

=0on

theP

etersand

Moldowan

[1993]scale)wereu

sedforaverage




(num



DBTPandVNi

ratioswerenotu

sedinthechem

ometric

analysis

AbbreviationsBNH


9C 2

3=C 1

9C 2


4C 2

3=C 2

4tetracyclicC 2


005)C

28C

29St=C 2

8C 2

9ste

ranes


9H=C 2

930-norhopaneC

30hopane


35SC 3

4S=C 3

5homohopane22SC 3



aturate+222

d13C a


etal1982)O

lH=oleananeC

30hopane

(Moldowan

etal

1994)R o

Eq=

equivalentvitrinite

reflectance(Boreham

etal1

988)TAS3(CR)=

(C20+C 2

1)(C 2

0+C 2

1+C 2

6+C 2

7+C 2

8)triarom


atogram[also

calledTA(I)TA(I+

II)asm

odified

fromMackenzieetal

(1981)

byPetersetal(2005)]

TsTm

=C 2



=vanadium

nickel(Lew

an1984)

Peters et al 125














Peters et al 127

















Peters et al 129

















Peters et al 131

CONCLUSIONS





APPENDIX






REFERENCES CITED

































Peters et al 133










































Peters et al 135












Peters et al 119













METHODS

Laboratory Analyses


Sample Screening


Peters et al 121















Peters et al 123










Table2


Biom


LosAngelesBasin

OilFamilie

s

Family

Number

ofSamples

BulkPropertiesforNo

nbiodegraded

Samples

Maturity

Shale

Carbonate

Redox

Terrigenous

Angiosperm

s

APIG

ravity

Sulfurwt

Saturates

Arom

atics

ltC

15Fraction

MPI-1

R oEq

TAS3(CR)

TsTm

C 24C 2

3C 2

9H

DBTP

C 35C 3

4SBN

HH

VNi

CVC 2

8C 2

9St

C 19C 2

3OlH

116

282ndash59(5)

100

ndash006

(4)

125

ndash013

(5)

399ndash38(5)

108

ndash018

098

ndash013

012

ndash002

050

ndash003

077

ndash005

049

ndash001

018

ndash009

081

ndash008

017

ndash008

070

ndash023

(4)-

160

ndash032

173

ndash004

0016ndash00030143ndash0017

128

326ndash20(6)

055

ndash000

(1)

133

ndash008

(6)

474ndash45(6)

112

ndash016

100

ndash011

014

ndash005

055

ndash004

086

ndash003

046

ndash002

018

ndash015

071

ndash003

018

ndash001

036

ndash048

(3)-

162

ndash012

169

ndash005

0023ndash00020219ndash0012

1319

302ndash45(13)

106

ndash091

(7)

131

ndash021

(15)

442ndash56(15)

113

ndash014

101

ndash010

016

ndash005

063

ndash009

094

ndash008

045

ndash002

021

ndash013

076

ndash009

021

ndash004

000

ndash000

(7)-

189

ndash051

160

ndash007

0035ndash00140260ndash0067

215

353ndash45(5)

020

ndash001

(3)

189

ndash021

(5)

589ndash65(5)

149

ndash019

126

ndash013

019

ndash004

083

ndash022

088

ndash005

042

ndash003

005

ndash005

064

ndash009

021

ndash008

000

ndash000

(3)-

204

ndash029

161

ndash003

0047ndash00080516ndash0115

226

326ndash21(6)

023

ndash012

(6)

157

ndash013

(6)

554ndash51(6)

139

ndash008

119

ndash005

021

ndash003

059

ndash004

090

ndash003

043

ndash001

007

ndash001

061

ndash003

015

ndash002

000

ndash000

(5)-

174

ndash042

170

ndash002

0029ndash00030298ndash0014

318

235ndash00(1)

142

ndash044

(2)

091

ndash004

(2)

301ndash69(2)

099

ndash010

092

ndash007

008

ndash001

042

ndash004

074

ndash004

054

ndash003

032

ndash011

087

ndash006

032

ndash008

045

ndash015

(4)-

188

ndash043

166

ndash004

0016ndash00040131ndash0020

325

mdashmdash

mdashmdash

104

ndash008

095

ndash006

007

ndash001

042

ndash002

072

ndash004

056

ndash001

025

ndash007

088

ndash002

034

ndash002

041

ndash003

(3)-

240

ndash019

158

ndash003

0019ndash00020140ndash0008

3315

mdash158

ndash000

(1)

098

ndash000

(1)

202ndash00(1)

113

ndash015

101

ndash010

006

ndash001

034

ndash001

070

ndash005

057

ndash002

033

ndash011

089

ndash007

028

ndash001

070

ndash000

(1)-

213

ndash019

165

ndash003

0013ndash00020116ndash0018

418

268ndash00(1)

057

ndash000

(1)

090

ndash000

(1)

423ndash00(1)

107

ndash018

097

ndash012

008

ndash004

041

ndash007

085

ndash006

057

ndash007

030

ndash010

095

ndash005

032

ndash005

026

ndash029

(5)-

263

ndash050

158

ndash003

0016ndash00020141ndash0017

427

259ndash87(4)

322

ndash062

(2)

052

ndash008

(7)

304ndash54(7)

103

ndash010

095

ndash007

009

ndash001

043

ndash002

099

ndash009

051

ndash003

071

ndash019

096

ndash011

026

ndash009

180

ndash032

(2)-

148

ndash059

164

ndash009

0017ndash00050139ndash0016

510

308ndash21(3)

124

ndash098

(3)

105

ndash042

(5)

453ndash221(5)102

ndash017

093

ndash012

008

ndash005

042

ndash014

074

ndash006

054

ndash004

025

ndash016083

ndash010

055

ndash032

013

ndash026

(4)-

152

ndash031

154

ndash009

0030ndash00090171ndash0022

614

260ndash65(7)

242

ndash034

(7)

080

ndash023

(12)

324ndash97(12)

086

ndash011

082

ndash008

007

ndash002

044

ndash005

080

ndash003

054

ndash002

055

ndash021

088

ndash013

032

ndash010

075

ndash074

(8)-

094

ndash024

144

ndash007

0024ndash00050142ndash0016




wport-Inglew




samples

(biodegradationrank

=0on

theP

etersand

Moldowan

[1993]scale)wereu

sedforaverage




(num



DBTPandVNi

ratioswerenotu

sedinthechem

ometric

analysis

AbbreviationsBNH


9C 2

3=C 1

9C 2


4C 2

3=C 2

4tetracyclicC 2


005)C

28C

29St=C 2

8C 2

9ste

ranes


9H=C 2

930-norhopaneC

30hopane


35SC 3

4S=C 3

5homohopane22SC 3



aturate+222

d13C a


etal1982)O

lH=oleananeC

30hopane

(Moldowan

etal

1994)R o

Eq=

equivalentvitrinite

reflectance(Boreham

etal1

988)TAS3(CR)=

(C20+C 2

1)(C 2

0+C 2

1+C 2

6+C 2

7+C 2

8)triarom


atogram[also

calledTA(I)TA(I+

II)asm

odified

fromMackenzieetal

(1981)

byPetersetal(2005)]

TsTm

=C 2



=vanadium

nickel(Lew

an1984)

Peters et al 125














Peters et al 127

















Peters et al 129

















Peters et al 131

CONCLUSIONS





APPENDIX






REFERENCES CITED

































Peters et al 133










































Peters et al 135













METHODS

Laboratory Analyses


Sample Screening


Peters et al 121















Peters et al 123










Table2


Biom


LosAngelesBasin

OilFamilie

s

Family

Number

ofSamples

BulkPropertiesforNo

nbiodegraded

Samples

Maturity

Shale

Carbonate

Redox

Terrigenous

Angiosperm

s

APIG

ravity

Sulfurwt

Saturates

Arom

atics

ltC

15Fraction

MPI-1

R oEq

TAS3(CR)

TsTm

C 24C 2

3C 2

9H

DBTP

C 35C 3

4SBN

HH

VNi

CVC 2

8C 2

9St

C 19C 2

3OlH

116

282ndash59(5)

100

ndash006

(4)

125

ndash013

(5)

399ndash38(5)

108

ndash018

098

ndash013

012

ndash002

050

ndash003

077

ndash005

049

ndash001

018

ndash009

081

ndash008

017

ndash008

070

ndash023

(4)-

160

ndash032

173

ndash004

0016ndash00030143ndash0017

128

326ndash20(6)

055

ndash000

(1)

133

ndash008

(6)

474ndash45(6)

112

ndash016

100

ndash011

014

ndash005

055

ndash004

086

ndash003

046

ndash002

018

ndash015

071

ndash003

018

ndash001

036

ndash048

(3)-

162

ndash012

169

ndash005

0023ndash00020219ndash0012

1319

302ndash45(13)

106

ndash091

(7)

131

ndash021

(15)

442ndash56(15)

113

ndash014

101

ndash010

016

ndash005

063

ndash009

094

ndash008

045

ndash002

021

ndash013

076

ndash009

021

ndash004

000

ndash000

(7)-

189

ndash051

160

ndash007

0035ndash00140260ndash0067

215

353ndash45(5)

020

ndash001

(3)

189

ndash021

(5)

589ndash65(5)

149

ndash019

126

ndash013

019

ndash004

083

ndash022

088

ndash005

042

ndash003

005

ndash005

064

ndash009

021

ndash008

000

ndash000

(3)-

204

ndash029

161

ndash003

0047ndash00080516ndash0115

226

326ndash21(6)

023

ndash012

(6)

157

ndash013

(6)

554ndash51(6)

139

ndash008

119

ndash005

021

ndash003

059

ndash004

090

ndash003

043

ndash001

007

ndash001

061

ndash003

015

ndash002

000

ndash000

(5)-

174

ndash042

170

ndash002

0029ndash00030298ndash0014

318

235ndash00(1)

142

ndash044

(2)

091

ndash004

(2)

301ndash69(2)

099

ndash010

092

ndash007

008

ndash001

042

ndash004

074

ndash004

054

ndash003

032

ndash011

087

ndash006

032

ndash008

045

ndash015

(4)-

188

ndash043

166

ndash004

0016ndash00040131ndash0020

325

mdashmdash

mdashmdash

104

ndash008

095

ndash006

007

ndash001

042

ndash002

072

ndash004

056

ndash001

025

ndash007

088

ndash002

034

ndash002

041

ndash003

(3)-

240

ndash019

158

ndash003

0019ndash00020140ndash0008

3315

mdash158

ndash000

(1)

098

ndash000

(1)

202ndash00(1)

113

ndash015

101

ndash010

006

ndash001

034

ndash001

070

ndash005

057

ndash002

033

ndash011

089

ndash007

028

ndash001

070

ndash000

(1)-

213

ndash019

165

ndash003

0013ndash00020116ndash0018

418

268ndash00(1)

057

ndash000

(1)

090

ndash000

(1)

423ndash00(1)

107

ndash018

097

ndash012

008

ndash004

041

ndash007

085

ndash006

057

ndash007

030

ndash010

095

ndash005

032

ndash005

026

ndash029

(5)-

263

ndash050

158

ndash003

0016ndash00020141ndash0017

427

259ndash87(4)

322

ndash062

(2)

052

ndash008

(7)

304ndash54(7)

103

ndash010

095

ndash007

009

ndash001

043

ndash002

099

ndash009

051

ndash003

071

ndash019

096

ndash011

026

ndash009

180

ndash032

(2)-

148

ndash059

164

ndash009

0017ndash00050139ndash0016

510

308ndash21(3)

124

ndash098

(3)

105

ndash042

(5)

453ndash221(5)102

ndash017

093

ndash012

008

ndash005

042

ndash014

074

ndash006

054

ndash004

025

ndash016083

ndash010

055

ndash032

013

ndash026

(4)-

152

ndash031

154

ndash009

0030ndash00090171ndash0022

614

260ndash65(7)

242

ndash034

(7)

080

ndash023

(12)

324ndash97(12)

086

ndash011

082

ndash008

007

ndash002

044

ndash005

080

ndash003

054

ndash002

055

ndash021

088

ndash013

032

ndash010

075

ndash074

(8)-

094

ndash024

144

ndash007

0024ndash00050142ndash0016




wport-Inglew




samples

(biodegradationrank

=0on

theP

etersand

Moldowan

[1993]scale)wereu

sedforaverage




(num



DBTPandVNi

ratioswerenotu

sedinthechem

ometric

analysis

AbbreviationsBNH


9C 2

3=C 1

9C 2


4C 2

3=C 2

4tetracyclicC 2


005)C

28C

29St=C 2

8C 2

9ste

ranes


9H=C 2

930-norhopaneC

30hopane


35SC 3

4S=C 3

5homohopane22SC 3



aturate+222

d13C a


etal1982)O

lH=oleananeC

30hopane

(Moldowan

etal

1994)R o

Eq=

equivalentvitrinite

reflectance(Boreham

etal1

988)TAS3(CR)=

(C20+C 2

1)(C 2

0+C 2

1+C 2

6+C 2

7+C 2

8)triarom


atogram[also

calledTA(I)TA(I+

II)asm

odified

fromMackenzieetal

(1981)

byPetersetal(2005)]

TsTm

=C 2



=vanadium

nickel(Lew

an1984)

Peters et al 125














Peters et al 127

















Peters et al 129

















Peters et al 131

CONCLUSIONS





APPENDIX






REFERENCES CITED

































Peters et al 133










































Peters et al 135















Peters et al 123










Table2


Biom


LosAngelesBasin

OilFamilie

s

Family

Number

ofSamples

BulkPropertiesforNo

nbiodegraded

Samples

Maturity

Shale

Carbonate

Redox

Terrigenous

Angiosperm

s

APIG

ravity

Sulfurwt

Saturates

Arom

atics

ltC

15Fraction

MPI-1

R oEq

TAS3(CR)

TsTm

C 24C 2

3C 2

9H

DBTP

C 35C 3

4SBN

HH

VNi

CVC 2

8C 2

9St

C 19C 2

3OlH

116

282ndash59(5)

100

ndash006

(4)

125

ndash013

(5)

399ndash38(5)

108

ndash018

098

ndash013

012

ndash002

050

ndash003

077

ndash005

049

ndash001

018

ndash009

081

ndash008

017

ndash008

070

ndash023

(4)-

160

ndash032

173

ndash004

0016ndash00030143ndash0017

128

326ndash20(6)

055

ndash000

(1)

133

ndash008

(6)

474ndash45(6)

112

ndash016

100

ndash011

014

ndash005

055

ndash004

086

ndash003

046

ndash002

018

ndash015

071

ndash003

018

ndash001

036

ndash048

(3)-

162

ndash012

169

ndash005

0023ndash00020219ndash0012

1319

302ndash45(13)

106

ndash091

(7)

131

ndash021

(15)

442ndash56(15)

113

ndash014

101

ndash010

016

ndash005

063

ndash009

094

ndash008

045

ndash002

021

ndash013

076

ndash009

021

ndash004

000

ndash000

(7)-

189

ndash051

160

ndash007

0035ndash00140260ndash0067

215

353ndash45(5)

020

ndash001

(3)

189

ndash021

(5)

589ndash65(5)

149

ndash019

126

ndash013

019

ndash004

083

ndash022

088

ndash005

042

ndash003

005

ndash005

064

ndash009

021

ndash008

000

ndash000

(3)-

204

ndash029

161

ndash003

0047ndash00080516ndash0115

226

326ndash21(6)

023

ndash012

(6)

157

ndash013

(6)

554ndash51(6)

139

ndash008

119

ndash005

021

ndash003

059

ndash004

090

ndash003

043

ndash001

007

ndash001

061

ndash003

015

ndash002

000

ndash000

(5)-

174

ndash042

170

ndash002

0029ndash00030298ndash0014

318

235ndash00(1)

142

ndash044

(2)

091

ndash004

(2)

301ndash69(2)

099

ndash010

092

ndash007

008

ndash001

042

ndash004

074

ndash004

054

ndash003

032

ndash011

087

ndash006

032

ndash008

045

ndash015

(4)-

188

ndash043

166

ndash004

0016ndash00040131ndash0020

325

mdashmdash

mdashmdash

104

ndash008

095

ndash006

007

ndash001

042

ndash002

072

ndash004

056

ndash001

025

ndash007

088

ndash002

034

ndash002

041

ndash003

(3)-

240

ndash019

158

ndash003

0019ndash00020140ndash0008

3315

mdash158

ndash000

(1)

098

ndash000

(1)

202ndash00(1)

113

ndash015

101

ndash010

006

ndash001

034

ndash001

070

ndash005

057

ndash002

033

ndash011

089

ndash007

028

ndash001

070

ndash000

(1)-

213

ndash019

165

ndash003

0013ndash00020116ndash0018

418

268ndash00(1)

057

ndash000

(1)

090

ndash000

(1)

423ndash00(1)

107

ndash018

097

ndash012

008

ndash004

041

ndash007

085

ndash006

057

ndash007

030

ndash010

095

ndash005

032

ndash005

026

ndash029

(5)-

263

ndash050

158

ndash003

0016ndash00020141ndash0017

427

259ndash87(4)

322

ndash062

(2)

052

ndash008

(7)

304ndash54(7)

103

ndash010

095

ndash007

009

ndash001

043

ndash002

099

ndash009

051

ndash003

071

ndash019

096

ndash011

026

ndash009

180

ndash032

(2)-

148

ndash059

164

ndash009

0017ndash00050139ndash0016

510

308ndash21(3)

124

ndash098

(3)

105

ndash042

(5)

453ndash221(5)102

ndash017

093

ndash012

008

ndash005

042

ndash014

074

ndash006

054

ndash004

025

ndash016083

ndash010

055

ndash032

013

ndash026

(4)-

152

ndash031

154

ndash009

0030ndash00090171ndash0022

614

260ndash65(7)

242

ndash034

(7)

080

ndash023

(12)

324ndash97(12)

086

ndash011

082

ndash008

007

ndash002

044

ndash005

080

ndash003

054

ndash002

055

ndash021

088

ndash013

032

ndash010

075

ndash074

(8)-

094

ndash024

144

ndash007

0024ndash00050142ndash0016




wport-Inglew




samples

(biodegradationrank

=0on

theP

etersand

Moldowan

[1993]scale)wereu

sedforaverage




(num



DBTPandVNi

ratioswerenotu

sedinthechem

ometric

analysis

AbbreviationsBNH


9C 2

3=C 1

9C 2


4C 2

3=C 2

4tetracyclicC 2


005)C

28C

29St=C 2

8C 2

9ste

ranes


9H=C 2

930-norhopaneC

30hopane


35SC 3

4S=C 3

5homohopane22SC 3



aturate+222

d13C a


etal1982)O

lH=oleananeC

30hopane

(Moldowan

etal

1994)R o

Eq=

equivalentvitrinite

reflectance(Boreham

etal1

988)TAS3(CR)=

(C20+C 2

1)(C 2

0+C 2

1+C 2

6+C 2

7+C 2

8)triarom


atogram[also

calledTA(I)TA(I+

II)asm

odified

fromMackenzieetal

(1981)

byPetersetal(2005)]

TsTm

=C 2



=vanadium

nickel(Lew

an1984)

Peters et al 125














Peters et al 127

















Peters et al 129

















Peters et al 131

CONCLUSIONS





APPENDIX






REFERENCES CITED

































Peters et al 133










































Peters et al 135










Table2


Biom


LosAngelesBasin

OilFamilie

s

Family

Number

ofSamples

BulkPropertiesforNo

nbiodegraded

Samples

Maturity

Shale

Carbonate

Redox

Terrigenous

Angiosperm

s

APIG

ravity

Sulfurwt

Saturates

Arom

atics

ltC

15Fraction

MPI-1

R oEq

TAS3(CR)

TsTm

C 24C 2

3C 2

9H

DBTP

C 35C 3

4SBN

HH

VNi

CVC 2

8C 2

9St

C 19C 2

3OlH

116

282ndash59(5)

100

ndash006

(4)

125

ndash013

(5)

399ndash38(5)

108

ndash018

098

ndash013

012

ndash002

050

ndash003

077

ndash005

049

ndash001

018

ndash009

081

ndash008

017

ndash008

070

ndash023

(4)-

160

ndash032

173

ndash004

0016ndash00030143ndash0017

128

326ndash20(6)

055

ndash000

(1)

133

ndash008

(6)

474ndash45(6)

112

ndash016

100

ndash011

014

ndash005

055

ndash004

086

ndash003

046

ndash002

018

ndash015

071

ndash003

018

ndash001

036

ndash048

(3)-

162

ndash012

169

ndash005

0023ndash00020219ndash0012

1319

302ndash45(13)

106

ndash091

(7)

131

ndash021

(15)

442ndash56(15)

113

ndash014

101

ndash010

016

ndash005

063

ndash009

094

ndash008

045

ndash002

021

ndash013

076

ndash009

021

ndash004

000

ndash000

(7)-

189

ndash051

160

ndash007

0035ndash00140260ndash0067

215

353ndash45(5)

020

ndash001

(3)

189

ndash021

(5)

589ndash65(5)

149

ndash019

126

ndash013

019

ndash004

083

ndash022

088

ndash005

042

ndash003

005

ndash005

064

ndash009

021

ndash008

000

ndash000

(3)-

204

ndash029

161

ndash003

0047ndash00080516ndash0115

226

326ndash21(6)

023

ndash012

(6)

157

ndash013

(6)

554ndash51(6)

139

ndash008

119

ndash005

021

ndash003

059

ndash004

090

ndash003

043

ndash001

007

ndash001

061

ndash003

015

ndash002

000

ndash000

(5)-

174

ndash042

170

ndash002

0029ndash00030298ndash0014

318

235ndash00(1)

142

ndash044

(2)

091

ndash004

(2)

301ndash69(2)

099

ndash010

092

ndash007

008

ndash001

042

ndash004

074

ndash004

054

ndash003

032

ndash011

087

ndash006

032

ndash008

045

ndash015

(4)-

188

ndash043

166

ndash004

0016ndash00040131ndash0020

325

mdashmdash

mdashmdash

104

ndash008

095

ndash006

007

ndash001

042

ndash002

072

ndash004

056

ndash001

025

ndash007

088

ndash002

034

ndash002

041

ndash003

(3)-

240

ndash019

158

ndash003

0019ndash00020140ndash0008

3315

mdash158

ndash000

(1)

098

ndash000

(1)

202ndash00(1)

113

ndash015

101

ndash010

006

ndash001

034

ndash001

070

ndash005

057

ndash002

033

ndash011

089

ndash007

028

ndash001

070

ndash000

(1)-

213

ndash019

165

ndash003

0013ndash00020116ndash0018

418

268ndash00(1)

057

ndash000

(1)

090

ndash000

(1)

423ndash00(1)

107

ndash018

097

ndash012

008

ndash004

041

ndash007

085

ndash006

057

ndash007

030

ndash010

095

ndash005

032

ndash005

026

ndash029

(5)-

263

ndash050

158

ndash003

0016ndash00020141ndash0017

427

259ndash87(4)

322

ndash062

(2)

052

ndash008

(7)

304ndash54(7)

103

ndash010

095

ndash007

009

ndash001

043

ndash002

099

ndash009

051

ndash003

071

ndash019

096

ndash011

026

ndash009

180

ndash032

(2)-

148

ndash059

164

ndash009

0017ndash00050139ndash0016

510

308ndash21(3)

124

ndash098

(3)

105

ndash042

(5)

453ndash221(5)102

ndash017

093

ndash012

008

ndash005

042

ndash014

074

ndash006

054

ndash004

025

ndash016083

ndash010

055

ndash032

013

ndash026

(4)-

152

ndash031

154

ndash009

0030ndash00090171ndash0022

614

260ndash65(7)

242

ndash034

(7)

080

ndash023

(12)

324ndash97(12)

086

ndash011

082

ndash008

007

ndash002

044

ndash005

080

ndash003

054

ndash002

055

ndash021

088

ndash013

032

ndash010

075

ndash074

(8)-

094

ndash024

144

ndash007

0024ndash00050142ndash0016




wport-Inglew




samples

(biodegradationrank

=0on

theP

etersand

Moldowan

[1993]scale)wereu

sedforaverage




(num



DBTPandVNi

ratioswerenotu

sedinthechem

ometric

analysis

AbbreviationsBNH


9C 2

3=C 1

9C 2


4C 2

3=C 2

4tetracyclicC 2


005)C

28C

29St=C 2

8C 2

9ste

ranes


9H=C 2

930-norhopaneC

30hopane


35SC 3

4S=C 3

5homohopane22SC 3



aturate+222

d13C a


etal1982)O

lH=oleananeC

30hopane

(Moldowan

etal

1994)R o

Eq=

equivalentvitrinite

reflectance(Boreham

etal1

988)TAS3(CR)=

(C20+C 2

1)(C 2

0+C 2

1+C 2

6+C 2

7+C 2

8)triarom


atogram[also

calledTA(I)TA(I+

II)asm

odified

fromMackenzieetal

(1981)

byPetersetal(2005)]

TsTm

=C 2



=vanadium

nickel(Lew

an1984)

Peters et al 125














Peters et al 127

















Peters et al 129

















Peters et al 131

CONCLUSIONS





APPENDIX






REFERENCES CITED

































Peters et al 133










































Peters et al 135














Peters et al 127

















Peters et al 129

















Peters et al 131

CONCLUSIONS





APPENDIX






REFERENCES CITED

































Peters et al 133










































Peters et al 135

















Peters et al 129

















Peters et al 131

CONCLUSIONS





APPENDIX






REFERENCES CITED

































Peters et al 133










































Peters et al 135

















Peters et al 131

CONCLUSIONS





APPENDIX






REFERENCES CITED

































Peters et al 133










































Peters et al 135

CONCLUSIONS





APPENDIX






REFERENCES CITED

































Peters et al 133










































Peters et al 135































Peters et al 133










































Peters et al 135










































Peters et al 135

Chemometric recognition of genetically distinct oil families in … · 2016-01-28 · Chemometric...

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