COEFFICIENTS, AND VANE SHEAR STRENGTH · Electrical resistivity (horizontal) from 625 to 950 m...

43. DEEP SEA DRILLING PROJECT DRILL SITES 530 AND 532 IN THE ANGOLA BASIN AND ONTHE WALVIS RIDGE: INTERPRETATION OF INDUCTION LOG DATA, SONIC LOG DATA, AND

LABORATORY SOUND VELOCITY, DENSITY, POROSITY-DERIVED REFLECTIONCOEFFICIENTS, AND VANE SHEAR STRENGTH1

Robert E. Boyce, Deep Sea Drilling Project, Scripps Institution of Oceanography, La Jolla, California

ABSTRACT

From 0 to 277 m at Site 530 are found Holocene to Miocene diatom ooze, nannofossil ooze, marl, clay, and debris-flow deposits; from 277 to 467 m are Miocene to Oligocene mud; from 467 to 1103 m are Eocene to late Albian Ceno-manian interbedded mudstone, marlstone, chalk, clastic limestone, sandstone, and black shale in the lower portion;from 1103 to 1121 m are basalts.

In the interval from 0 to 467 m, in Holocene to Oligocene pelagic oozes, marl, clay, debris flows, and mud, veloci-ties are 1.5 to 1.8 km/s; below 200 m velocities increase irregularly with increasing depth. From 0 to 100 m, in Holoceneto Pleistocene diatom and nannofossil oozes (excluding debris flows), velocities are approximately equivalent to that ofthe interstitial seawater, and thus acoustic reflections in the upper 100 m are primarily caused by variations in densityand porosity. Below 100 or 200 m, acoustic reflections are caused by variations in both velocity and density. From 100to 467 m, in Miocene-Oligocene nannofossil ooze, clay, marl, debris flows, and mud, acoustic anisotropy irregularlyincreases to 10%, with 2 to 5% being typical.

From 467 to 1103 m in Paleocene to late Albian Cenomanian interbedded mudstone, marlstone, chalk, clastic lime-stone, and black shale in the lower portion of the hole, velocities range from 1.6 to 5.48 km/s, and acoustic anisotropiesare as great as 47% (1.0 km/s) faster horizontally. Mudstone and uncemented sandstone have anisotropies which irreg-ularly increase with increasing depth from 5 to 10% (0.2 km/s). Calcareous mudstones have the greatest anisotropies,typically 35% (0.6 km/s).

Below 1103 m, basalt velocities ranged from 4.68 to 4.98 km/s. A typical value is about 4.8 km/s.In situ velocities are calculated from velocity data obtained in the laboratory. These are corrected for in situ

temperature, hydrostatic pressure, and porosity rebound (expansion when the overburden pressure is released). Thesecorrections do not include rigidity variations caused by overburden pressures. These corrections affect semicon-solidated sedimentary rocks the most (up to 0.25 km/s faster). These laboratory velocities appear to be greater than thevelocities from the sonic log.

Reflection coefficients derived from the laboratory data, in general, agree with the major features on the seismicprofiles. These indicate more potential reflectors than indicated from the reflection coefficients derived using theGearhart-Owen Sonic Log from 625 to 940 m, because the Sonic Log data average thin beds.

Porosity-density data versus depth for mud, mudstone, and pelagic oozes agree with data for similar sediments assummarized in Hamilton (1976). At depths of about 400 m and about 850 m are zones of relatively higher porositymudstones, which may suggest anomalously high pore pressure; however, they are more probably caused by variationsin grain-size distribution and lithology.

Electrical resistivity (horizontal) from 625 to 950 m ranged from about 1.0 to 4.0 ohm-m, in Maestrichtian to Santo-nian-Coniacian mudstone, marlstone, chalk, clastic limestone, and sandstone. An interstitial-water resistivity curve didnot indicate any unexpected lithology or unusual fluid or gas in the pores of the rock. These logs were above the blackshale beds.

From 0 to 100 m at Sites 530 and 532, the vane shear strength on undisturbed samples of Holocene-Pleistocene dia-tom and nannofossil ooze uniformly increases from about 80 g/cm2 to about 800 g/cm2. From 100 to 300 m, vane shearstrength of Pleistocene-Miocene nannofossil ooze, clay, and marl are irregular versus depth with a range of 500 to 2300g/cm2; and at Site 532 the vane shear strength appears to decrease irregularly and slightly with increasing depth (gassyzone). Vane shear strength values of gassy samples may not be valid, for the samples may be disturbed as gas evolves,and the sediments may not be gassy at in situ depths.

INTRODUCTION

This chapter reports certain relationships among phys-ical properties, using samples from Deep Sea DrillingProject Sites 530 and 532 and selected well logs obtainedat Hole 53OA. Site 530 is in the Angola Basin and Site532 is on the Wal vis Ridge. These features are in thesoutheastern Atlantic Ocean (Fig. 1). The principal aimsof this chapter are as follows:

Hay, W. W., Sibuet, J.-C, et al., Init. Repts. DSDP, 75: Washington (U S. Govt.Printing Office).

1) To introduce additional systematic studies of com-pressional-wave (sound) velocity and acoustic anisotro-py for sediment, sedimentary rock, and basalt, and todetermine their relationships to wet-bulk density andporosity. Acoustic impedance and reflection coefficientsare derived. All of these are important for the proper in-terpretation of gravity, seismic reflection, seismic re-fraction, and sonobuoy data. Particularly important aredata for very young sediments from the upper 100 or200 m of the hole, which in the past have been too dis-turbed for proper study.

2) To study the Velocity and Induction Logs. This isimportant because if the porosity values derived from

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R. E. BOYCE

10° IM

Africa10° S

Figure 1. Location of Site 530 in the Angola Basin and Site 532 on the Walvis Ridge in the southeasternAtlantic Ocean off Africa. (Bathymetric contours = 4000 m depth.)

these logs do not agree within certain limits of error,then, assuming the logging data are accurate, one ormore of the following is indicated: (a) conductive metal-lic minerals, (b) anomalies in the salinities of interstitialwater, (c) an anomalous temperature, or (d) the pres-ence of hydrocarbons.

3) To study vane shear strength on undisturbed sam-ples of very young sediments from 0 to 300 m below theseafloor (these data are rare) as well as relationships tolithology, porosity, wet-bulk density, and compression-al velocity.

DEFINITIONS AND PROCEDURESSediment and basalt classification is discussed in the

Explanatory Notes to this volume. Wet-bulk density isthe ratio of weight of the wet-saturated sediment or rocksample to its volume, expressed in g/cm3. Wet-watercontent is the ratio of the weight of seawater in the sam-ple to the weight of the wet saturated sample, and is ex-pressed as a percentage. Porosity is the ratio of the porevolume in a sample to the volume of the wet saturatedsample, and is expressed as a percentage in some casesand as a fraction in others. All of these equations,derivations, and techniques are discussed in detail inBoyce, this volume.

METHODS

The following technique was used for sedimentary samples. Gener-ally, in the Glomar Challenger laboratories, an undisturbed (visiblyundistorted bedding), wet-saturated sample was cut and removedfrom a split core liner after the core had been on deck for about 4hours to allow it to approach room temperature. The sample was thencarefully cut (if necessary) with a diamond saw and smoothed with a

sharp knife or file to a D-shaped sample 2.5 cm thick and with a2.5-cm radius. Compressional-wave (sound) velocities (±2°7o) per-pendicular and parallel to bedding were measured with the HamiltonFrame velocimeter (Boyce, 1976a, and Boyce, this volume). Immedi-ately afterward, wet-bulk density was measured within ±2 or 3°7o us-ing special two-minute gamma-ray counts with the Gamma-Ray At-tenuation Porosity Evaluator (GRAPE) (Evans, 1965) as modified byBoyce (1976a, and this volume). Between various measurements, thesample was wrapped in plastic and stored in a sealed plastic box with awet sponge so that it would not dry out. The wet-water content, wet-bulk density, and porosity of a subsample were then determined byweighing the water-saturated sample in water and after drying for 24hours at 110°C. For the soft sediments at Hole 530B and Site 532,porosity-density was determined by the "cylinder technique." Thesewere processed at DSDP. The weight of evaporated water was cor-rected for salt content (35%0) to give the weight of seawater (Boyce,1976a; Boyce, this volume). The estimated precision of wet-bulk den-sity is ±0.01 g/cm3 (absolute), and the precision of wet-water contentand porosity is ±0.5% absolute units. Acoustic impedance, in unitsof (g 105)/(cm2 s), is obtained from the product of the vertical (ifpossible) velocity and the gravimetric (if possible) wet-bulk density.Laboratory results are reported in tables in the site summaries.

For basalts, velocities were measured when the basalt first arrivedin the laboratory; this allowed us to be certain that the sample wassaturated with water. Detailed methods are discussed in Boyce (thisvolume). All basalt GRAPE 2-minute wet-bulk densities, and gravi-metric wet-bulk densities, wet-water contents, and porosities were de-termined on minicores, using techniques identical to those employedfor hard sedimentary material.

In situ velocity and electrical resistivity were obtained from Gear-hart-Owen well-log combinations: (1) Compensated Sonic Log, Cali-per, and Gamma Ray, and (2) Induction, 16-Inch Normal and Gam-ma Ray. Tools and precautions regarding the data are discussed inBoyce (this volume). Only the Sonic and Induction Log data from 625to 945 m in Hole 53OA will be discussed in this chapter. See the sitesummary for further discussion and other logging data.

With respect to the accuracy of logging data, I do not have ab-solute techniques available (e.g., in situ standards or in situ beds withprecisely known in situ physical property values) with which to check

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INDUCTION LOG DATA

empirically the validity of the logging data. The Velocity Log data ap-pear to be low (7-15%) when compared to laboratory velocities (seesite summary, this volume), particularly where the hole is washed out.This is a common problem between logging velocity and ultrasonic ve-locity, measurements on core samples; for example, Jones and Wang(1981) partially attribute discrepancies to the following possibilities:(1) short spacing well logging tools, (2) attenuation, (3) physicallydisturbed borehole walls, and (4) biased core recovery, in that moreresistant higher velocity rocks and softer material may have been erod-ed away during coring.

Because we do not have any absolute method by which to evaluatethe logging data, any log-derived relationships between electrical resis-tivity, velocity, and density-porosity are subject to bias if the loggingtools are not working properly.

Electrical Resistivity

The electrical resistivity of a material is defined as theresistance, in ohms, between opposite faces of a unitcube of that material. If the resistance of a conductingcube with length L and cross-sectional area A is r, thenthe resistivity, Ro, is

Rn = rA/L = ohm-m (1)

Electrical conduction through saturated sediment iscomplicated by a framework that generally consists ofnonconducting mineral grains. If the sediment consistsof nonconducting minerals, electrical conduction is pri-marily through the interstitial water, whose conductivityvaries with temperature, salinity, and pressure (Horne,1965; Horne and Courant, 1964; Horne and Frysinger,1963; Thomas et al., 1934). Conduction through thefluid can be modified significantly, however, if there arepresent metallic minerals with appreciable conductivityor clay-type minerals that exchange or withdraw ionsfrom the interstitial water (de Witte, 1950a, b; Patnodeand Wyllie, 1950; Keller, 1951; Berg, 1952; Winsauerand McCardell, 1953; Wyllie, 1955). Charged colloid-al particles and exchanged ions are not necessarily re-moved from the sediment when the interstitial water issampled, so they do not contribute to what is normallythought of as the water salinity (Keller, 1951; Howell,1953).

The formation factor, F, is the ratio of the electricalresistivity of the saturated sediment, Ro, to the resis-tivity of the interstitial water, Rw, at the same tempera-ture and pressure (Archie, 1942):

(2)

The formation factor has been related to porosity andfluid salinity of rocks or sediments by Archie (1942;1947), Winsauer et al. (1952), and others (Appendix A).

If the mineral composition of the sediment forms anonconductive matrix, and if the interstitial water con-ductivity is high, then this ratio is considered to be the"true" formation factor. With increasing salinity of theinterstitial water, this "true" formation factor approach-es a constant value for a given porosity and rock sample(Patnode and Wyllie, 1950; Keller and Frischknecht,1966).

If sediments contain minerals which are conductors,then this ratio is considered to be an "apparent" forma-

tion factor and is less than the "true" formation factorof sediments for a given set of porosity, textural, and ce-mentation characteristics. The "apparent" formationfactor approaches a constant value with different salin-ities, at given porosity, only if the conductivity of the in-terstitial water is much greater than that of the con-ducting minerals (Berg, 1952; Howell, 1953; Wyllie andSouthwick, 1954; Wyllie, 1955).

The variation of the apparent formation factor withinterstitial water resistivity may be related in part to thedistribution of conducting grains in a sample. Wyllieand Southwick (1954) developed a model showing thatthe connected conducting grains are conductors in par-allel with, and isolated conducting grains are conductorsin series with, the interstitial fluid. If the interstitialfluid is a good conductor, all the conducting grains willcontribute to the overall conduction. If the interstitialfluid is a moderate or poor conductor, the conductinggrains in series with interstitial water will contribute areduced proportion of the overall conduction of therock matrix; thus, the formation factor appears to in-crease as the resistivity of the fluid increases.

Clay-type minerals with varying exchange capacitiesmay act as resistors or conductors relative to differentinterstitial water resistivities. Because of the clay-typeminerals and other possible conducting minerals, theformation factor (for a given sample) may not be con-stant for different interstitial water resistivities (Keller,1951; Wyllie, 1955; Berg, 1952; Wyllie and Gregory,1953; Winsauer et al., 1952; Winsauer and McCardell,1953; Wyllie and Southwick, 1954; Keller and Frisch-knecht, 1966).

The resistivity of interstitial water may be estimatedby measuring the resistivity of the water squeezed fromthe geologic sample or by taking it to be equal to the re-sistivity of seawater. However, interstitial-water sam-pling may not remove ions that are filtered or trappedby clay-type minerals (Scholl, 1963), and the naturalsediment compaction from overburden pressure maytrap or filter various ions as the fluid migrates; thus, theinterstitial fluid may have a chemical composition dif-ferent from that of the original interstitial seawater (Sie-ver et al., 1961; Siever et al., 1965). The electrical resis-tivity of the interstitial water determined, for example,by using the data of Thomas et al. (1934) may thereforebe in error, because their data apply to a chemical com-position identical to that of seawater.

Electrical resistivity through fresh sediment may beisotropic (Bedcher, 1965), but consolidated sedimentsand rocks have anisotropic resistivities. Resistivity par-allel to bedding is typically less than the resistivity per-pendicular to bedding (Keller, 1966; Keller and Frisch-knecht, 1966).

Textures of the individual mineral grains affect elec-trical resistivity. The more angular textures create alonger path length through the sediment and thus ahigher resistivity and a higher formation factor for agiven porosity (Wyllie and Gregory, 1953). The resistiv-ity is also affected by grain-size distribution, particular-ly for clay-type minerals. A finer grain size gives agreater surface area with ionic exchange capacity and so

1139

R. E. BOYCE

increases the number of ionic-cloud conductors in agiven sample. This is also true, to a lesser degree, ofnonclay-type minerals, such a quartz and feldspar (Kel-ler and Frischknecht, 1966).

We will interpret the DSDP Hole 53OA sonic andelectrical logs by a technique developed by the petro-leum industry (Schlumberger, rtl., 1972) called the"apparent electrical resistivity of the interstitial water"(Rwa curve). (Normally a density log is used, but we didnot get a successful density-logging run at these sites.)This technique will here involve calculating the porosityfrom the Sonic Log's velocity, based on the followingempirical equation derived from laboratory velocity-porosity data from cores taken within the same depthinterval in the hole (625 to 945 m):

Φ =0.527

(3)

where Φ = fractional porosity and V = velocity (km/s)from Sonic Log. Then, by using a simplified form ofArchie's (1942) equation for the Site 530 data:

F R0/Rwa = Φ~m = —2

(4)

(5)

By substituting in Equation 5 the "apparent formationresistivity" (Ra) (not corrected for borehole diameter,borehole fluids, or the thicknesses of beds with contrast-ing resistivity) from the Induction Log (measures in di-rection which is parallel to bedding) and the Φ derivedfrom the Sonic Log, we can then solve for Rwa.

If the formation is homogeneous calcareous oozewith a uniform pore-water salinity and a uniform andnormal temperature gradient, the "i?w α versus depth"plot will theoretically be a straight line, but Rwa will de-crease slightly because of increasing temperature withincreasing depth. The method is useful because Rwa willbe anomalously high if there are any unexpected zones(which can sometimes be very distinct) of (1) hydrocar-bons, (2) relatively fresh water in the pores, or (3) neg-ative-temperature anomalies. The Rwa curve will giveanomalously low values if there are any unexpectedzones of (1) electrical conductors (metallic deposits), (2)relatively saltier pore waters, or (3) high-temperatureanomalies. Since the composition of the pore fluids isknown from samples of the sedimentary rocks collectedon the Challenger (Gieskes, this volume), and we knowthe temperature of the formation, we therefore knowwhat range of Rwa to expect and should thus be able toidentify the anomalies. If hydrocarbons are present, theapproximate pore-water saturation, Swt equals (Rwa ex-pected/Rwa anomaly)172 when using Equation 4.

Sound Velocity

Compressional-sound velocity in isotropic materialhas been defined (Wood, 1941; Bullen, 1947; Birch,1961; Hamilton, 1971) as

V=^LQb

4s/3\ 1 / 2

(6)

where Fis the compressional velocity; ρb is the wet-bulkdensity in g/cm3 and ρb = ρwΦ + (1 - Φ)Qg (here Φ isthe fractional porosity of the sediment or rock and thesubscripts b, g, and w represent the wet-bulk density,grain density, and water density, respectively); x is theincompressibility or bulk modulus; and 5 is the shear(rigidity) modulus.

Where samples are anisotropic, x and s may haveunique values for the corresponding vertical and hori-zontal directions. See Laughton (1957); Carlson andChristensen (1977); Gregory (1977); and Bachman (1979)for discussions of anisotropy.

Compressional velocity of sediments and rocks hasbeen related to the sediment components by Wood(1941), Wyllie et al. (1956), Nafe and Drake (1957), andothers, whose equations are listed in Appendix B. Thesewill be discussed later. Velocity is related to miner-alogical composition, fluid content, water saturation ofpores, temperature, pressure, grain size, texture, cemen-tation, direction with respect to bedding or foliation,and alteration, as summarized by Press (1966). Recent-ly, Hamilton (1978) has summarized velocity-densityrelationships of sediment and rock of the seafloor.Christensen and Salisbury (1975) have summarized ve-locity-density relationships of basalt under pressure.

Basalt velocities at one atmosphere pressure havebeen published for cores recovered on Leg 37 (Hynd-man, 1977); Leg 46 (Matthews, 1979), and Legs 51, 52,53 (Salisbury et al., 1980; Donnelly et al., 1980; Hama-no, 1980); Boyce (1981), and others.

We did not have density log data, which are normallyused with sonic log data to calculate acoustic imped-ance. Therefore, in order to calculate acoustic imped-ance, we empirically calibrated the velocity from theSonic Log, using equations derived from velocity-im-pedance measurements from cores. This calibration isbased on cross-plots of laboratory-measured velocityversus laboratory-measured impedance; measurementswere made on cores in the same depth interval in Hole53OA as were the logging data (625 to 945 m). The fol-lowing empirical equation was derived:

/ = -1.9 g»105

cm2 s(3.0 -*λ\ cm3/

(V) (7)

where V is velocity (km/s) and / is acoustic impedance,(g 105)/(cm2 s). Therefore by substituting velocity (km/s) from the Sonic Log into Equation 7, we could cal-culate acoustic impedance. However, Equation 7 shouldnot be used for any other universal purpose beyond thecalibration of these logging data. From this Sonic Log-derived impedance data, Sonic-Log derived reflectioncoefficients (R.C.) were calculated:

R.C. = (8)

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INDUCTION LOG DATA

where Io is a rolling average of impedance 0.5 meterabove the plotted reflection-coefficient data point, andIx is a rolling average of impedance for 0.5 m below theplotted reflection-coefficient data point.

Reflection coefficients (from 0 to 1121 m) are alsocalculated from the laboratory-measured velocity andimpedance data (see raw data in tabular form in the sitesummaries, this volume). These are done very simply byusing the upper and lower impedance values as they arelisted in their tables, and plotting the reflection coef-ficient value at the same depth as the lower impedancevalue (except for the seawater/seafloor interface). Be-cause of this very simple approach, investigators mustbe careful about precisely correlating the laboratory-de-rived reflection coefficients to their seismic profiles.

Calculations of in situ velocities from laboratory-measured velocities on cores are corrected for (1) hydro-static pressure and in situ temperature, and (2) hydro-static pressure, in situ temperature, plus porosity re-bound (Hamilton, 1976), expansion after overburdenpressure is released. The two possible values for in situvelocity are calculated, since the porosity rebound hasnot been completely proven. Techniques for calculatingin situ velocities are discussed in Boyce (1976b). Thesedata are presented in Tables 1 and 2. They assume a 5%(absolute units) porosity rebound for all rock >30%porosity; a 2.5% rebound for rocks with porosities be-tween 20 and 30%; and no rebound for rocks with po-rosities less than 20%. They do not include correctionsfor rigidity, which is created by grain-to-grain overbur-den pressure (Hamilton, 1965).

Vane Shear Strength

Shear strength of a soil or sediment mass is the sum-mation of the forces of friction, cohesion, and bondingwhich combine to resist failure by rupture along a slipsurface or by excessive plastic deformation under ap-plied stresses (Moore, 1964). Shear strength is a complexproperty which is also related to the rate of shearing, themanner and rate of stress application, mineralogy (claytype), cementation, grain-size distribution and packing,sample disturbance, pore pressure, permeability anddrainage of the pore water during shearing (Richards,1961; Moore, 1964; Wu, 1966; Scott and Schoustra,1968; Lambe and Whitman, 1969; Kravitz, 1970; andothers).

According to Richards (1961) and Kravitz (1970), thefollowing shear failure theory is the Coulomb (1776)failure equation as modified by Hvorslev (1936; 1937).Shear strength (g/cm2) of a sediment at failure, r f, is asfollows:

— c + (σ — µ) tan (9)

where c = cohesion, g/cm2; σ = normal stress on theplane of failure, (g/cm2); µ = excess pressure in porewater, g/cm2; Φ = angle of internal friction, and (σ - µ)= effective stress, g/cm2. Equation 9 has two compo-nents: cohesion, c, and friction, (σ - µ) tan 0. As sum-marized by Hamilton (1971), shear strength in sands,without significant amounts of fine silt and clay are

defined by the friction component (i.e., these are cohe-sionless sediments). Most silt-clay sediments have bothcohesion and friction (under normal stress). A few claysmay have no angle of internal friction, in which case theshear strength is defined by cohesion alone.

fclay= C (10)

According to Kravitz (1970), in studies involvingcompletely saturated clays of low permeability, such asthose found in ocean environments, shear strength isusually obtained under conditions of no change in watercontent. This procedure is called undrained or quicktesting. During undrained (quick) testing, the normalstress is zero, and the saturated sediment then behaveswith respect to the applied stresses at failure as a purelycohesive material with an angle of shearing resistanceequal to zero. When these conditions are met the equa-tion for shear strength is expressed as rf = c.

However, according to Moore (1964), Equation 8 isused mainly as a simplified relationship, and for the con-venience of calculating engineering properties of soils, itis generally understood that actual isolation of the co-hesional and frictional components of sediments is theo-retically unrealistic.

The relationships of Equations 9 and 10 to undrainedshear strength in saturated clayey sediments are dis-cussed by Schmertmann and Osterberg (1960), Richards(1961), Wu (1966), Hamilton (1971), Kravitz (1970),and others. Lambe (1960) discusses the shear strength ofcoarse sediments with respect to the additive relation-ships of cohesion, friction, interference, and dilatancy.

The following are some examples of the physicalchanges which may occur in a sediment sample when itshears: (1) the sample may expand or contract depend-ing on the grain-size distribution and packing structure;(2) the shearing stress may be in part directed on thepore water trapped in the sediment if the sample is veryfine grained and impermeable (undrained sample); (3)or shearing force may be entirely directed on the grain-to-grain structure if the sample's grain size is large andthe sample is highly permeable, allowing the water todrain (drained sample); (4) if a sample is moderatelypermeable, then the shear strength will be in part relatedto (a) the rate at which the shearing stress is applied, and(b) the rate which the pore water drains out of the sam-ple.

For vane shear measurements in this chapter, a fine-grained sample was selected so that permeability is lowenough that the sample is assumed to be "undrained"(unless the core samples are gassy) during the shear test.To enhance this relationship the vane shear speed mustbe very rapid (Lambe and Whitman, 1969; Scott andSchoustra, 1968) and thus the DSDP vane shear deviceis set at 89° of torque per minute (compared with thetypical 6° per minute suggested in ASTM, 1975). Theseshear strength measurements are conducted under lab-oratory pressures and temperatures.

An attempt was made to obtain an undisturbed sam-ple. A criterion for disturbance is visibly undistortedbedding, although a truly undisturbed sample does not

1141

R. E. BOYCE

Table 1. Laboratory sound velocity and calculated in situ velocity, Hole 53OA.

Core-Section(interval in cm)

3,CC -4-4, 91-934-5, 81-827-1, 131-1357-3, 49-517-6, 46-488-5, 23-258-6, 135-1378-7, 51-5310-2, 26-2710-3, 0-310-6, 10-1211-1, 29-3111-2, 135-13712-4, 97-10012-5, 0-312-5, 135-13713-2, 135-13713-3, 140-14214-1, 110-11214-2, 46-4814-2, 98-10015-2, 6-815-4, 144-14615-6, 93-9516-1, 77-7817-1, 6-718-2, 25-2718-3, 146-15018-5, 102-10419-1, 140-15019-4, 143-14519-6, 134-13620-1, 143-14520-3, 143-14720-5, 133-13621-1, 145-14721-3, 132-13421-5, 149-15022-2, 130-13222^t, 90-9322-6, 11-1223-1, 10-1524-2, 0-324-2, 60-6324-3, 145-14725-3, 75-7725-7, 58-6026-3, 105-10726-4, 12-1426-5, 106-10827-4, 138-14027-5, 138-14027-6, 138-14028-6, 105-10729-2, 75-7729-4, 75-7729-6, 73-7530-2, 38-4030-5, 38-4031-3, 18-2031-5, 18-2031-6, 18-2032-1, 75-7732-2, 75-7732-3, 75-7733-2, 5-733-3, 5-733-4, 5-734-3, 70-7234-5, 105-10834-7, 60-6235-2, 7-1035-4, 63-6535-5, 32-3536-1, 61-6337-1, 105-10837-2, 102-10437-2, 126-12837.CC (0-3)38-1, 0-338-1,44-4638-2, 28-3039-1, 8-1039-1, 70-7239-2, 65-6740-1, 94-9740-2, 103-10740-4, 32-3541-1,40-4241-1, 105-10741-3, 39-4142-1, 42-4542-1, 145-14742-2, 3-442.CC (3-7)43-1, 64-6743-1,80-8343-2, 137-14044-1,22-2544-1, 77-7944-1, 143-14745-1, 20-2246-1, 18-2047-1, 0-347-1, 123-12447-1, 147-15047-2, 18-2048-1, 12-1448-1, 48-5048-1, 123-125

Depth inhole

144.10158.91160.31183.31185.49189.96197.72200.35201.01212.26213.50218.10220.29222.85234.97235.50236.85241.85243.40249.60250.46250.98259.56263.92266.43268.27277.06288.25290.96293.52297.40301.97304.84306.93309.93312.87316.45319.32322.49327.30329.90332.11334.10345.00345.60347.95356.75362.58366.55367.12369.56377.88379.38380.88390.07393.25396.25399.24402.38406.88413.18416.18417.81420.25421.75423.25430.55432.05433.55442.20445.55448.10449.57453.13454.32458.11468.06469.52469.76471.13476.50476.94478.28486.08486.70488.15496.44498.04500.32505.40506.05508.39515.%515.95516.03517.92524.64524.80526.87533.72534.27534.93543.20552.68562.00563.23563.47563.68571.63571.98572.73

1Beds

(km/s)

4.8101.5201.4761.5611.5231.5601.5531.577

—1.5341.5071.5681.6201.6261.4921.5731.5661.5961.5621.5891.5361.5791.6411.5651.5891.6341.6261.6381.6391.6231.6341.6221.6251.6171.5821.5821.6171.5981.6121.6021.6211.6702.807?1.5291.6071.658gassy1.6081.6121.6111.5861.5931.6161.6281.5831.6511.711?1.6691.6851.7381.6331.7051.7051.6291.6901.694?1.7441.6811.7611.664?1.7201.7591.6841.7751.7941.7021.9653.9001.7443.0283.6431.6771.9011.7342.6953.6771.8591.9282.0584.0811.5962.0213.9903.7891.8961.673?1.8781.7504.3971.8422.290?1.8111.7671.7954.5181.9363.6121.8663.4871.8291.872

Compressional-sc

XBeds

(km/s)

4.672—

1.5451.531

——

1.537—

1.505—

1.502—

1.5721.6131.578

—1.593

————

1.5541.581

—1.5741.6091.5251.6291.6251.5991.5921.6011.5991.6031.5931.5901.5871.6131.5911.587

—1.720

—1.5731.5891.6231.609gassy1.620gassy1.6431.6341.6481.6501.6191.6012.065?1.6161.625

—1.5851.6441.621

_—

2.100?1.6601.6551.6572.053?1.6471.6881.626e

1.6951.6341.686

——

1:578—

3.4681.6821.6991.6291.9892.8741.6491.8111.9523.9431.5991.494?

—3.522

—1.849?1.7811.6614.1751.7852.512?1.6701.6761.720

—1.891

—1.7053.3981.7171.736

und velocityAnisotropy

l - j .(km/s)

_—

-0.0690.030——

0.016———

0.005—

0.0480.013

-0.086—

-0.027————

0.0250.060—

0.0150.0250.1010.0090.0140.0240.0420.0210.0290.014

-0.011-0.008

0.030-0.015

0.0210.015—

-0.050—

-0.0440.0180.035——

-0.008—

-0.61-0.041-0.032-0.022-0.036

0.050-0.354

0.0530.060—

0.0480.0610.084——

-0.4060.0840.0260.1040.389?0.0730.0710.0580.0800.1600.016——

0.166—

0.175-0.005

0.2020.1050.7060.8030.2100.1170.1060.138

-0.0030.527?—

0.267—

-0.1760.0970.0890.2220.057

-0.2220.1410.0910.075—

0.045—

0.1610.0890.1120.136

( |-X)/X' (%)

_—

-4 .42.0

——1.0

———0.3

—3.10.8

-5 .4—

-1.7_———1.63.8

—1.01.66.60.60.91.52.61.31.80.9

-0 .7-0 .5

1.9-0 .9+ 1.3+ 0.9—

-2.9—

-2.81.12.2

——

-0.5—

-3 .7-2 .5-1 .9-1 .4-2 .2

3.1-17.1

3.33.7

_3.03.75.2

—_

-19.35.11.66.3

18.9?4.44.23.64.79.80.9

——10.5—5.0

-0 .311.96.4

35.527.912.76.55.43.5

-0 .235.3?—7.6

—-9.5

5.45.45.33.2

-8 .88.45.44.4

—2.4

—9.42.66.57.8

CO

920202020202020202020202020202020202020202020202020202020202020202020202021212121212!2121212021202020202020202020202020202020202020202020202020202020202020202020202020202020202020212120212121222222222222212120202021202020

Hydrostaticpressurea

(kg/cm2)

494.6496.2496.3498.7498.9499.4500.2500.5500.5501.7501.8502.3502.5502.8504.0504.1504.2504.8504.9505.6505.6505.7506.6507.0507.3507.5508.4509.6509.8510.1510.5511.0511.3511.5511.8512.1512.5512.8513.1513.6513.9514.1514.3515.4515.5515.7516.6517.3517.7517.7518.0518.8519.0519.1520.1520.4520.7521.0521.4521.8522.5522.8523.0523.2523.4523.5524.3524.4524.6525.5525.8526.1526.3526.6526.7527.1528.2528.3528.3528.5529.0529.1529.2530.0530.1530.2531.1531.3531.5532.0532.1532.3533.1533.1533.1533.3534.0534.0534.3535.0535.0535.1535.9536.9537.9538.0538.0538.1538.9538.9539.0

In situtemperature

CO

8.79.39.3

10.210.310.510.810.910.911.411.411.611.711.812.312.312.412.612.612.912.912.913.313.513.613.614.014.414.514.614.815.015.115.215.315.415.615.715.816.016.116.216.316.716.716.817.217.417.617.617.718.018.118.118.518.618.818.919.019.219.419.519.619.719.819.820.120.220.220.620.720.820.921.021.121.221.621.721.721.722.022.022.022.322.422.422.822.822.923.123.123.223.523.523.523.623.923.924.024.224.324.324.625.025.425.425.425.425.825.825.8

In situvelocity

water0

(km/s)

1.5681.5691.5691.5741.5741.5751.5761.5761.5761.5781.5791.5791.5801.5801.5821.5821.5821.5831.5831.5841.5891.5841.5861.5861.5871.5871.5881.5901.5901.5911.5911.5921.5921.5931.5931.5931.5941.5951.5951.5961.5961.5961.5971.5981.5981.5981.6001.6001.6011.6011.6011.6021.6031.6031.6041.6041.6051.6051.6061.6061.6071.6071.6081.6081.6081.6081.6091.6101.6101.6111.6111.6121.6121.6121.6121.6131.6141.6141.6141.6141.6151.6151.6151.6161.6161.6161.6181.6181.6181.6181.6181.6191.6201.6201.6201.6201.6211.6211.6211.6221.6221.6221.6231.6241.6251.6251.6251.6251.6261.6261.626

Velocityfor hyd

x>rrectedrostatic

pressure andtemperature

II (km/s)

4.8251.5671.5231.6131.5751.6131.6071.630

1.5901.5641.6241.6771.6831.5521.6321.6251.6561.6231.6501.5981.6401.7031.6281.6531.6981.6911.7041.7051.6911.7011.6911.6961.6871.6521.6521.6881.6701.6841.6751.6941.7422.8621.6051.6821.732

—1.6841.6901.6891.6661.6721.6951.7071.6641.7311.7911.7501.7661.8181.7161.7871.7881.7131.7731.7771.8271.7661.8451.7501.8051.8451.7711.8601.8791.7902.0493.9481.8323.0923.6961.7671.9871.8242.7673.7301.9482.0162.1444.1271.6912.1084.0393.8421.9871.7681.9701.8444.4381.9362.3741.9051.8631.8914.5582.0303.6711.9623.5501.9271.969

X (km/s)

4.689_

1.5921.583

1.591

1.559

1.559

1.6291.6701.637

_1.652

_—_

1.6161.644

1.6381.6731.5911.6961.6921.6671.6601.6701.6681.6731.6631.6601.6581.6851.6631.660

—1.791

_1.6481.6641.6971.686

1.697

1.7201.7121.7271.7291.6991.6822.1391.6971.707

1.6691.7271.705

——

2.1761.7451.7411.7432.1321.7341.7751.7141.7821.7221.774

—1.669

—3.5241.7721.7891.7212.0742.9421.7431.9012.0404.0001.6941.592

3.580—

1.9401.8751.7574.2201.8802.5921.7671.7741.818

—1.986

—1.8043.4621.8171.835

Velocity correctedfor hydrost itic pres-sure, temperature,

and porosity rebounde

1 (km/s)

4.8251.5871.5431.6331.5951.6331.6271.650

—1.6101.5841.6441.7071.7031.5721.6521.6121.6861.6431.6701.6181.6701.7331.6581.6731.7281.7211.7531.7541.7401.7311.7211.7261.7261.6911.7111.7271.7091.7231.7051.7241.7722.8621.6351.7121.762

—1.7141.7201.7191.6961.7121.7351.7371.6941.7711.8301.7801.8061.8481.7361.8171.8181.7431.8031.7%1.8571.7961.8841.7801.8451.8831.8111.9001.9191.8302.1473.9481.8623.1903.7841.7872.0361.8542.8063.7991.9762.0752.2424.1271.7112.1774.0393.9502.0451.7972.0281,8744.4381.9842.4721.9441.9031.9314.5582.0893.7402.0013.6571.9752.027

X (km/s)

4.689

1.6121.603

——

1.611

1.579—

1.579—

1.6591.6901.657

—1.655

———

1.6461.674' —1.6681.7031.6111.7451.7441.7161.6901.7001.7081.7721.7021.6991.6971.7211.7021.690

—1.821

—1.6741.6941.7271.706J.

1.707—

1.7501.7521.7671.7591.7291.7222.1781.7271.747

—1.6891.7571.735

——

2.1961.7751.7711.7822.1621.7731.8131.7541.8211.7621.814

——

1.699—

3.6121.7921.8381.7512.1133.0111.7731.9602.1384.0001.7141.660

—3.688

—1.9701.9331.7844.2201.9282.6901.8061.8141.857

—2.045

—1.8433.5621.8661.894

Lithology (G.S.A. color number)

Vesicular-vuggy basalt pebble. Velocity orientation(?)Nannofossil ooze (5Y 5/2)Mottled clay (5Y 3/2)Nannofossil ooze (5Y 5/2)Laminated nannofossil ooze (5Y 5/2)Clay (5Y 3/2)Clay (5Y 3/2)Nannofossil ooze (5Y 5/2)Nannofossil ooze (5Y 5/2)Nannofossil marl (5Y 4/2)Nannofossil ooze (5Y 5/2)Clay (5Y 3/2)Clay (5Y 3/2)Sandy nannofossil ooze (5Y 4/2)Nannofossil ooze (5Y 5/2)Clay (5Y 3/2)Nannofossil marl (5Y 5/2)Clay (5Y 3/2)Nannofossil ooze (5Y 5/2)Clay (5Y 5/2)Clay (5Y 3/2)Nannofossil marl (5Y 4/2)Clay (5Y 3/2)Nannofossü marl (5Y 5/1)Nannofossil ooze (5Y 6/1)Clay (5Y 3/2)Clay (5Y 3/2)Nannofossil marl (5Y 4/3)Clay (5Y 5/3)Clay (5Y 5/3)Clay (5Y 3/2)Clay (5Y 3/2)Clay (5Y 3/2)Claystone (5Y 3/2)Claystone (5Y 3/2)Claystone (5Y 3/2)Claystone (5Y 3/2)Claystone (5Y 2/2)Claystone (5Y 3/2)Clay (10Y 4/2)Clay (5Y 5/2)Clay (5Y 5/2)Breccia (chert with CO3 cement)Nannofossil-foraminifer ooze (disturbed) (12YR 5/2)Claystone (5Y 5/6)Clay (10Y 4/4)Clay (10Y 4/2) (gassy)Clay (10Y 4/2) (gassy)Claystone (10Y 4/2) (gassy)Claystone (10Y 4/2)Claystone (10Y 4/2)Claystone (10Y 4/2)Claystone (10Y 4/2)Claystone (10Y 4/2)Claystone (10Y 4/2) (gassy)Claystone (10Y 4/2) (gassy)Claystone (10Y 4/2) (gassy)Claystone (10Y 4/2) (gassy)Claystone (10Y 4/2)Claystone (10Y 3/2)Claystone (10Y 4/2)Claystone (10Y 4/2)Claystone (10Y 4/2)Claystone (10Y 4/2)Claystone (10Y 4/2)Claystone (10Y 4/2)Claystone (10Y 4/2)Claystone (10Y 4/2)Claystone (10Y 4/2)Claystone (10Y 4/2) (disturbed)Claystone (10Y 3/2)Claystone (10Y 4/2)Claystone (5YR 3/2)Claystone (10YR and 5YR 7/2)Claystone (10Y 4/2)Claystone (10Y 4/2)Chalk (10YR 8/2)Basalt pebble (5Y 3/2)Mudstone (10Y 4/2)Calcarenite (10YR 3/2), (air?)Coarse CO3 cemented sandstone (10YR 8/2)Claystone (10YR 5/2)Nannofossil chalk (10YR 8/2)Claystone (10YR 8/2)CO3 cemented claystone (10YR 8/2)CO3 cemented sandstone (10YR 8/2)Mudstone (10Y 4/2)Foraminifer-nannofossil chalk (10YR 8/2)Foraminifer-nannofossil chalk (10YR 8/2)CO3 cemented sandstone (10YR 8/2)Mudstone (10YR 8/2)Laminated mudstone (10Y 4/2-6/2)Chert (5Y 5/2)CO3 cemented sandstone (5Y 6/2)Laminated calcareous mudstone (10 5/2)Mudstone (5Y 3/2)Lenticular mudstone (5GY 6/1)Mudstone (10YR 8/2)CO3 cemented sandstone (5Y 6/2)Mudstone (10Y 8/2)Coarse CO3 cemented sandstone (5Y 6/2)Mudstone (5Y 3/2)Mudstone (5Y 3/2)Mudstone (5Y 3/2)Chert (5Y 3/2)Laminated mudstone (5Y 5/2)CO3 cemented sandstone (10YR 8/2)Mudstone (5YR 3/2)CO3 cemented sandstone (10Y 8/2)Laminated mudstone (5Y 5/2)Mudstone (5Y 3/2)

1142

INDUCTION LOG DATA

Table 1. (Continued).


49-1, 26-2849-1, 41-4249-2, 0-351-1, 50-5251-1, 134-13651-4, 134-13652-1, 65-6752-1, 110-11253-1, 16-1853-1, 133-13653-2, 37-4054-1, 36-3854-1, 95-9755-1, 93-9555-2, 90-9255-3, 36-3855-4, 76-7856-1, 31-3356-1, 74-7656-2, 96-9857-1, 39-4057-1, 65-6757-2, 66-6858-1, 110-11259-1, 98-10059-2, 43-4560-1, 3-560-1, 18-2060-1, 50-5261-1, 22-2561-2, 144-14761-3, 43-4562-1, 50-5262-3, 97-9962-4, 10-1263-1, 12-1463-2, 31-3363-3, 73-7564-1, 18-2064-1, 52-5564-2, 65-6767-1, 60-6267-2, 56-5867-3, 107-10968-1, 23-2568-1, 60-6368-2, 109-11269-1,43-4569-2, 101-10369-3, 27-3070-1, 123-12770-2, 0-370-3, 141-14371-1, 3-471-2, 59-6171-2, 112-11471-3, 16-1872-1, 65-6772-2, 16-1872-5, 131-13373-1, 134-13673-2, 87-9073-5, 118-12074-1, 79-8174-2, 20-2274-4, 102-10475-1, 10-1275-2, 34-3675-3, 77-7976-1,26-2876-2, 110-11276^1, 55-5777-1, 8-1077-2, 52-5477-4, 2-377-5, 70-7278-1, 61-6378-2, 75-7778-3, 78-8078-*, 147-14979-1, 138-14079-3, 56-5879-4, 75-7779-5, 98-10080-1, 128-13080-1, 141-14280-3, 1-381-1, 134-13681-2, 19-2181-3, 70-7282-1, 3-482-1, 34-3682-2, 75-7782-3, 120-12383-1,48-5083-2, 132-13383-3, 24-2683^, 66-6884-1, 30-3284-1, 115-11784-2, 142-14484-3, 147-14985-1, 3-485-1, 38-4085-2, 14-1785-3, 1-386-1, 138-14086-2, 146-14886-4, 146-14887-1,95-9887-1, 128-130

Depth inhole(m)

581.24581.41582.50600.50601.34605.84610.15610.60619.16620.33620.87628.86629.45638.93640.40641.36643.26647.82648.26649.96657.39657.65659.16667.60676.98677.93685.53685.68686.01695.22697.94698.43705.00708.47709.10714.12715.81717.73723.68724.02725.65752.60754.06756.07761.73762.10764.09771.43773.51774.27781.73782.00784.91790.03792.09792.62793.16800.15801.16806.81810.34811.37816.18819.29820.20824.02828.10829.84831.77837.76840.10842.55847.08849.02851.52853.70857.11858.75860.24862.47867.39869.56871.25872.98876.78876.91878.51886.34886.69888.70894.53894.84896.75898.71904.48906.83907.24909.16913.30914.15915.92917.42922.03922.38923.64925.01932.38932.94936.96940.95941.28

Beds(km/s)

1.9203.3423.7723.5001.8842.0012.0252.6533.2922.7032.0302.8562.5434.1082.0623.6062.1754.3332.2892.3282.3354.0112.5812.3515.478

—4.9432.2612.5613.3242.0442.0602.4222.6573.6783.8233.3032.2594.9482.0953.3612.9632.3362.3703.0112.2082.6713.4882.3162.5322.2862.6472.4673.1602.0932.2532.5272.5323.1722.5912.4522.5472.7482.4892.4352.2562.2072.2142.1572.0572.2892.1832.4772.3152.0732.0732.1192.2422.2042.3271.9784.6162.0402.1602.5332.6102.4192.4642.3642.7764.5442.3952.5592.3932.4022.0562.4223.9512.3882.2684.7282.9752.6534.4502.5322.1142.3732.5072.4251.8012.211

Compressional-sound velocity

X

Beds(km/s)

1.7653.0603.5063.3371.7831.8421.827

—2.363

—1.8552.7562.2903.7821.9673.2561.9504.4612.0512.0782.0043.1822.3972.0215.3002.6204.4952.1772.4732.3111.8781.8921.8532.4912.8083.3592.2451.9044.3721.943

—2.9622.0441.9512.7181.9752.6523.4202.0942.3221.9952.4842.2773.1291.8541.9942.4012.1132.4432.427

—2.4182.7362.4542.3882.1631.8862.0931.8852.0712.3891.9532.0962.0761.9671.9552.0451.9591.9842.0212.0634.4961.9341.9022.1012.3242.2102.2702.1332.5604.4772.2412.3132.0492.1031.9082.121

—2.1912.0124.3892.1042.4654.6282.1761.9152.0902.1552.2571.8332.036

Anisotropy| _ x

(km/s)

0.1550.2820.2660.1630.1010.1590.198—

0.929—

0.1750.1000.2530.3260.0950.3500.225

-0.1280.2380.2500.3310.8290.1840.3300.178—

0.4480.0840.0881.0130.1660.1680.5690.1660.8700.4641.0580.3550.5760.152—

0.0010.2920.4190.2930.2330.0190.0680.2220.2100.2910.1630.1900.0310.2390.2590.1260.4190.7290.164—

0.1290.0120.0350.0470.0930.3210.1210.272

-0.014-0.100

0.2300.3810.2390.1060.1180.0740.2830.2200.306

-0.0850.0120.1060.2580.4320.2860.2090.1940.2310.2160.0670.1540.2460.3440.2990.1480.301—

0.1970.2560.3390.8710.188

-0.1780.3560.1990.2830.3520.168

-0.0320.175

(|-x)/x(%)

8.89.27.94.95.78.6

10.8—39.3—9.43.6

11.08.64.8

10.711.5

-2 .911.612.016.526.17.7

16.33.4

—10.03.93.6

43.8

8.930.76.7

31.013.847.118.613.27.8

—0.0

14.321.510.811.80.72.0

10.69.0

14.66.68.31.0

12.913.05.2

19.829.86.8

—5.30.41.42.04.3

17.05.8

14.4-0 .7-4 .211.818.211.55.46.03.6

14.411.115.1

-4 .32.75.5

13.520.612.49.58.5

10.88.41.56.9

10.616.814.27.8

14.2—9.0

12.77.7

41.47.6

-3 .816.410.413.516.37.4

-1.78.6

Temp.(°C)

2121212021202020202020202020202020202020202020202020202020202020202020202020202020202020202020202020202020202020202020202020VJ

20202020202020202020202020202020

202020

202020202020202020202020202020202020202020202020202020

Hydrostaticpressure"(kg/cm2)

539.9539.9540.0541.9542.0542.4542.9542.9543.8543.9544.0544.0544.9545.9546.0546.1546.3546.8546.8547.0547.8547.8547.9548.8549.8549.8550.7550.7550.7551.7552.0552.0552.7553.0553.1553.6553.8554.0554.6554.7554.8557.6557.8558.0558.6558.6558.8559.6559.8559.9560.6560.7561.0561.5561.7561.8561.8562.5562.6563.2563.6563.7564.2564.5564.6565.0565.4565.6565.8566.4566.7566.9567.4567.6567.9568.1568.4568.6568.8569.0569.5569.7569.9570.1570.5570.5570.6571.5571.5571.7572.3572.3572.5572.7573.3573.6573.6573.8574.2574.3574.5574.7575.2575.2575.3575.5576.2576.3576.7577.1577.1

In situh

temperatureCO

26.126.226.226.927.027.127.327.327.727.727.728.128.128.528.528.628.628.828.828.929.229.229.329.630.030.030.330.330.330.730.8

31.131.231.331.531.531.631.831.931.933.033.133.133.433.433.533.833.833.934.234.234.334.534.634.634.634.934.935.235.335.435.235.735.735.936.036.136.236.436.536.636.836.936.937.037.237.337.337.437.637.737.837.838.038.038.038.438.438.438.738.738.838.839.139.239.239.339.439.539.539.639.839.839.839.940.240.240.440.540.6

In situvelocity

water0

(km/s)

1.6271.6271.6271.6291.6291.6301.6301.6301.6311.6311.6311.6321.6321.6331.6331.6341.6341.6341.6341.6341.6351.6351.6351.6361.6371.6371.6381.6381.6381.6391.6391.6391.6401.6401.6401.6411.6411.6411.6421.6421.6421.6441.6451.6451.6451.6451.6461.6461.6461.6471.6471.6471.6481.6481.6481.6481.6481.6491.6491.6501.6501.6501.6501.6511.6511.6511.6511.6521.6521.6531.6531.6531.6541.6541.6541.6541.6551.6551.6551.6551.6561.6561.6561.6561.6561.6561.6571.6571.6571.6581.6581.6581.6581.6581.6591.6591.6591.6601.6601.6601.6601.6601.6611.6611.6611.6611.6621.6621.6621.6631.663

Velocity correctedfor hydrostaticpressure andtemperature

1 (km/s)

2.0173.4083.8293.5641.9832.0992.1222.7363.3622.7862.1282.9362.6304.1612.1603.6712.2724.3812.3842.4222.4294.0672,6702.4465.501

_4.9782.3602.6533.3982.1492.1642.5182.7483.7443.8863.3792.3604.9852.2013.4363.0492.4392.4723.0972.3142.7663.5632.4222.6312.3922.7432.5693.2442.2042.3602.6272.6333.2562.6912.5562.6482.8442.5932.5402.3662.3182.3262.2702.1742.4002.2962.5832.4262.1902.1902.2362.3562.3192.4382.1004.6662.1602.2772.6402.7142.5292.5732.4762.8774.5972.5072.6662.5052.5152.1782.5344.0212.5022.3854.7763.0722.7594.5062.6432.236

2.6192.5391.9342.332

X (km/s)

1.8653.1323.5693.4051.8841.9431.928

2.453_

1.9572.8382.3833.8422.0683.3292.0524.5062.1512.1772.1063.2572.4902.1235.3272.7094.5412.2782.5672.4091.9872.0001.9632.5862.8953.4342.3472.0144.4232.053

_3.0482.1542.0632.8112.0872.7483.4962.2042.4272.1082.5852.3843.2141.9722.1082.5052.2252.5462.531

_2.5232.8322.5592.4942.2752.0052.2082.0052.1872.4972.0732.2132.1932.0872.0752,1642.0802.1052.1412.1824.5492.0572.0262.2192.4362.3262.3852.2512.6672.5312.3572.4272.1702.2232.0342.241

_2.3102.1364.4472.2262.5774.6792.2972.0432.2142.2772.3761.9652.162

Velocity correctedfor hydrostatic pres-sure, temperature,

and porosity rebounde

| (km/s)

2.0753.4873.9373.6332.0322.1952.1702.8143.4592.8542.1863.0242.7274.1612.2283.7882.3314.3812.4522.5192.4884.0672.7672.5145.501

_4.9782.4272.7503.4952.2062.2232.6152.8643.8413.9933.4562.4174.9852.2693.5343.1282.5062.5303.1552.3822.8643.6502.4882.7292.4602.8412.6663.2442.2632.4292.6862.6923.3542.7592.6142.7072.9032.6412.5982.4142.3762.3742.3192.2122.4682.3452.6512.4832.2392.2392.2852.4142.3772.5062.1974.6662.1992.3252.7172.8122.6262.6702.5542.9844.5972.6042.7732.5752.6122.2462.6024.0892.5992.4534.7763.1402.8374.5062.7402.2952.5852.7152.6372.0012.429

X (km/s)

1.9243.2113.6763.4731.9332.0401.976

2.550_

2.0152.9262.4803.8422.1353.4462.1104.5062.2192.2752.1653.2572.5882.1925.3272.7684.5412.3462.6642.5062.0442.0592.0602.7022.9923.5402.4232.0714.4232.121

_3.1272.2222.122

2.155

3.5842.2722.5242.1762.6822.4813.2142.0302.1762.5632.2832.6442.600

2.5812.8912.6062.5522.3232.0642.2572.0542.2262.5652.1212.2802.2512.1362.1242.2132.1392.1632.2092.2804.5492.0962.0742.2972.5332.4232.4822.3292.7744.5312.4542.5342.2392.3212.1022.309

_2.4072.2044.4472.2942.6544.6792.3942.1012.3102.3732.4732.0322.259


Mudstone (5Y 3/2)Laminated CO3 cemented sandstone (10YR 8/2)Coarse CO3 cemented sandstone (10YR 8/2)CO3 cemented sandstone (10YR 8/2)Mudstone (5Y 3/2)Mudstone (5Y 5/2)Mudstone (5Y 3/2)CO3 cemented sandstone (10YR 8/2)Laminated calcareous mudstone (5Y 3/2 to 7/2)CO3 cemented sandstone (5Y 8/1-5GY 3/2)Mudstone (5GY 4/1)CO3 cemented sandstone (5GY 3/2)Lenticular, calcareous mudstone (5G 4/1 to 6/1)Coarse CO3 sandstone (5GY 3/2)CO3 mudstone (5G 6/1)Laminated CO3 cemented sandstone (5Y 8/1)Calcareous mudstone (5GY 3/2-2/2)Laminated CO3 cemented sandstone (N8)Mudstone (5GY 4/1)Calcareous mudstone (5GY 6/1; 5G 4/1)Mudstone (5GY 4/1)CO3 cemented sandstone (N5)CO3 cemented sandstone (5Y 7/2)Calcareous mudstone (5Y 7/2)CO3 cemented sandstone (N5)Mudstone (5GY 4/1)Coarse CO3 cemented sandstone (N5)Calcareous mudstone (5Y 7/2)Mudstone (5GY 4/1)Calcareous Mudstone (5Y 7/7)Mudstone (5GY 4/1; 5Y 4/1)Mudstone (5Y 4/1)Calcareous mudstone (5Y 4/1)Sandstone grading to mudstone (5GY 4/1)Sandstone grading to mudstone (5GY 4/1)Laminated sandstone (N5)Calcareous mudstone (5Y 4/1)Mudstone (5G 4/1)Laminated CO3 cemented sandstone (N5)Mudstone (5G 4/1; 5Y 4/1)Laminated sandstone (N5)Laminated sandstone (5Y 4/1)Mudstone (5Y 4/1)Mudstone (5G 4/1)Mudstone (5G 4/1)Mudstone (5Y 4/1)Laminated size-graded sandstone (5Y 4/1)Laminated sandstone (5Y 4/1)Mudstone (5Y 4/1)Laminated calcareous mudstone (5Y 4/1)Laminated mudstone (5G 4/1)Laminated sandstone (5GY 3/1)Calcareous mudstone (5G 5/1)Coarse sandstone (5GY 3/1)Mudstone (5G 5/1)Calcareous mudstone (5GY 6/1)Sandstone (5G 4/1)Sandstone (5G 2/1)Mudstone (5GY 4/1)Laminated sandstone (5GY 4/1)Laminated sandstone (5G 4/1)Sandstone (5G 4/1)Spotted sandstone (5G 4/1)Spotted sandstone (5G 4/1)Spotted sandstone (5G 4/1)Sandstone (5G 6/1)Mudstone (SYR 3/1)Sandstone (5G 6/1)Calcareous, size-graded mudstone (5G 4/1)Sandstone (5G 6/1)Mudstone (5GY 2/1)Mudstone (SYR 3/1)Laminated mudstone (5G 6/1; 5YR 3/1)Spotted calcareous mudstone (5G 6/1; 5Y 5/2)Cross-bedded sandstone (5G 3/1)Sandstone (5G 6/1)Massive sandstone (5GY 2/1)Laminated-lenticular mudstone (5YR 2/1)Cross-bedded mudstone (5Y 2/1; 5Y 4/1)Mudstone (5YR 4/1)Mudstone (5YR 4/1)CO3 cemented sandstone (5GY 6/1)Sandstone (5Y 7/1)Mudstone (5Y 2/1)Mudstone (5YR 4/1; 5G 2/1)Laminated sandstone (5YR 6/1)Lenticular mudstone (SYR 4/1)Mudstone (5R 4/3)Mudstone (5R 4/3)Laminated CO3 cemented sandstone (5Y 4/1)Laminated CO3 cemented sandstone (5Y 4/1)Laminated sandstone (5Y 4/1)Lenticular mudstone (5YR 4/1)Mudstone (5YR 3/4)Lenticular mudstone (5YR 4/4)Laminated sandstone (5Y 4/1)Mudstone (5Y 4/4)Laminated CO3 cemented sandstone (5Y 4/1)Lenticular mudstone (5YR 3/4)Mudstone (5YR 4/4)Laminated CO3 cemented sandstone (5Y 4/1)Laminated sandstone (5Y 4/1)Mudstone (5YR 3/4)CO3 cemented sandstone (5Y 4/1)Lenticular mudstone (5YR 4/4)Laminated sandstone (5Y 4/1)Mudstone (5YR 3/4)Lenticular mudstone (SYR 3.5/4)Lenticular mudstone (5GY 3/2)Mudstone (5G 5/1)Lenticular mudstone (5YR 4/1)

1143

R. E. BOYCE



87-2, 118-12088-1, 18-2088-1, 70-7288-1, 128-13088.CC (2-4)89-1, 78-8089-2, 105-10789-3, 130-13289-4, 50-5290-1, 45-4790-3, 30-3291-1, 140-14291-2, 94-9691-3, 98-100914, 12-1493-1, 133-13593-2, 72-7493-3, 60-6293-5, 3-594-1, 11-1394-1, 30-3294-2, 140-14295-1, 102-10495-2, 137-13995-3, 118-12096-1, 73-7796-2, 75-7796-2, 98-10097-1, 26-2897-3, 5-798-1, 18-2098-2, 20-2298-3, 10-1299-1, 138-14099-2, 40-4299-2, 68-7099-4, 135-137100-1, 140-142100-2, 94-96100-3, 34-361004, 36-38101-1, 22-24101-2, 33-35101-3, 84-86101-5, 136-138102-1, 15-17102-2, 47-49102-4, 2-4102-5, 2-5103-1, 46-48103-2, 102-103103-3, 40-42103-4, 2-4104-1, 120-122104-2, 100-102104-3, 38-40104-5, 144-146105-1, 48-50105-3, 18-201054, 115-117105-5, 115-117106-1, 8-10106-1, 8-10107-1, 12-14107-1, 12-14107-2, 24-26107-2, 24-26107-3, 41-43107-3, 41-43108-1, 19-21108-1, 19-21108-2, 58-60108-2, 58-60108-3, 81-83108-3, 81-83

Depth inhole

942.68949.18949.70950.28953.48958.78960.55962.30963.00967.45970.30977.46978.44979.98980.62991.33992.22993.60996.03999.11999.30

1001.901009.021010.881012.121017.731019.251019.481026.261029.051035.181036.701038.101045.381045.901046.181049.851054.401055.441056.341057.861062.221063.831065.841069.361071.151072.971075.521077.021080.461082.521083.401084.501086.201087.501088.381092.151094.481097.181099.651101.151103.081103.081105.121105.121106.741106.741108.411108.411112.141112.141114.08

114.081115.831115.83

Beds(km/s)

2.0452.0293.6752.4692.2192.1072.0582.0942.0472.3941.9511.7342.1372.7724.288

2.3952.2322.1112.7502.081?2.0632.1862.1812.3601.8812.2762.0454.4212.0791.9762.1002.1651.8632.0893.8412.1702.2582.2012.3342.2712.2482.2952.4142.253

2.2462.4062.369

2.4202.6082.4443.0722.370

2.4172.3633.2523.0532.3193.813d

3.774d

4.8034.6934.7274.7114.9245.0134.8574.9624.6784.5834.6974.764

Corr

X

Beds(km/s)

1.858—

2.8122.4112.0841.9491.8411.9481.8572.2191.8131.7881.9902.3103.6921.9052.1912.C5:1

1.927

2.2831.8911.9331.9992.2012.1152.1981.8994.3821.8691.8931.9061.974

—

1.9102.9081.9242.0301.677?2.1692.0732.0302.1372.1991.7522.1542.0892.1751.8712.0962.227

2.8612.1202.1942.089

2.9982.8322.092

_

3.858d

4.829—

4.678_

5.030_

4.846

4.659—

4.495

pressional-soAniso

- ±(km/s)

0.195—

0.8630.0580.1350.1580.2170.1460.1900.1750.138

-0.0540.1470.4620.5960.1510.2040.1690.1840.666

- 0 . 2 0 20.1720.2530.1820.159

-0.2340.0780.1460.0390.2100.0830.1940.191_

0.1790.9330.2460.2280.524?0.1650.1980.2180.1580.2150.5010.2320.1570.2310.498_

0.1930.3090.2180.2110.2500.269

0.3360.2540.2210.227

- 0 . 0 8 4

- 0 . 1 3 6

0.033

-0 .017_

0.116_

- 0 . 7 6—

0.269

und velocitytropy

( | . X ) / X( % )

10.5—

30.72.4

6.5

8.111.87.5

10.27.97.6

- 3 . 07.4

20.016.17.99.38.2

9.532.0

- 8 . 89.1

13.19.17.2

-12.43.57.7

0.911.24.4

10.29.7

_

9.4

32.112.811.231.2?

7.69.6

10.77.49.8

28.610.87.5

10.626.6_

8.7

13.49.87.4

11.812.315.716.6

8.5

7.810.9

- 2 . 2

- 2 . 8

0.7_

- 0 . 3_

2.4_

- 1 . 6

6.0

TempCO

20

20

202020

20

202020

2020

20

2020

20

20

2 0

20

20

2020

• i :

20202020

20

202020

2020202020

202020

2020

2020

2020

I0

29

20

20Cold (15°

20Cold

20Cold

20Cold

20Cold

20Cold

20Cold

20

Hydrostatic

pressure(kg/cm2)

577.3578.0578.0578.1578.4579.0579.1579.3579.4579.9580.1580.9581.0581.2581.2582.3582.4

:>s:.s582.8583.1583.2583.4584.2584.3584.5585.1585.2585.2585.9586.2586.9587.0587.2587.9588.0

588.4588.9

589.0

589.^589.8590.0590.4590.6590.8591.0591.2591.6591.8591.9592.0592.1592.3592.4592.8593.0593.3593.5593.7

C) 593.9593.9594.1594.1594.3594.3594.4594.4

594.8595.0595.0595.2595.2

In situtemperature

(°C)

40.640.940.940.9

t

11.01.3

1.311.41.4

11.61.72.02.02.1

2.12.62.6

2.62.7

2.92.9

3.03.3

3.33.4

3.63.73.7

44.044.144.344.444.444.744.744.744.945.145.145.245.245.445.545.545.745.7

45.946.046.146.246.246.346.346.446.446.646.746.846.946.947.047.047.147.147.247.247.247.247.447.447.547.547.547.5

In situvelocity

waterc

(km/s)

1.6631.6641.6641.6641.6641.6651.6651.6651.6651.6651.6661.6661.6661.6671.6671.6681.6681.6681.6681.6691.6691.6691.6701.6701.6701.6701.6701.6701.6711.6711.6721.6721.6721.6731.6731.6731.6731.6741.6741.6741.6741.6751.6751.6751.6751.6751.6761.6761.6761.6761.6771.6771.6771.6771.6771.6771.6781.6781.6781 .6781.6781.6791.6791.6791.6791.6791.6791.6791.6791.6801.6801.6801.6801.6801.680

Velocity correctedfor hydr

pressuretemper

1 (km/s)

2.1712.155

2.5842.3412.2332.1852.2202.1752.5122.0821.8722.2632.8804.3522.1862.5152.3572.2402.8602.2112.1942.3142.3092.483

2.4012.1774.4822.2112.1122.2322.2952.004

3.9212.3012.3872.3322.4612.4002.3^82.4242.5392.3832.5122.3772.5322.497

_

2.5472.7292.5703.178

2.545

3.3533.1612.4503.897

—4.855

—

4.782—

4.973—

4.908—

4.735—

4.753—

>statica n d

turex (km/s)

1.989—

2.9172.5272.2102.0801.9752.0791.9902.3421.9481.9242.1202.4323.7732.0402.3172.1932.0612.2142.4072.0272.0692.1332.3292.2452.3262.0364.4442.0082.0.122.0442.110

—

2.0493.0172.0632.1661.824?2.3012.2082.1672.2712.3311.8982.2872.2252.3092.0142.2322.3602.4102.3592.9742.2562.3282.2272.1673.1072.9472.230

———

—————————

—

—

Velocit)for hydr

corrected>static pres-

sure, temperature,and porosI (km/s)

2.229

3.7552.6902.4382.3202.244

!

2.2332.6192.1411.9302.3502.9484.3522.282?

2.4152.3082.9192.3282.2522.3822.4062.5902.086

2.2454.4822.2792.1792.3002.3632.0702.2903.9212.3792.4552.400

2.4972.455:. -,5 1

2.4712.619

2.5392.593

—2.6532.835

3.2652.5952.6952.642

?

3.2482.5563.897

—

4.855—

4.782—

4.973—

4.908—

4.735—

4.753—

lty rebound^X (km/s)

2.048—

2.9172.6332.3072.1672.0332.1472.0492.4492.0071.9822.2082.5003.7732.136?2.4242.2512.1302.2722.5142.0852.1372.2302.4352.3132.4322.1044.4442.0762.0992.1122.178

—

2.1173.0172.1402.2341.902?2.4082.3952.2442.3392.4281.9852.3942.3212.4152.1112.3292.4662.5362.4563.0612.3532.4342.3242.264

?3.0342.336

——————————————


Mudstone (SYR 3/4)Mudstone (5YR 3/2)Dolomitic mudstone (5YR 3/2)Sandstone (5Y 5/1)Lenticular mudstone (5G 5/1)Lenticular mudstone (5GY 6 / 1 ; 5G 5/1)Mudstone (SYR 3/2)Calcareous mudstone (10YR 4/2)Mudstone (5YR 3/4)Mudstone (5Y 3/4)Mudstone (5GY 6/1)Mudstone (SYR 4/1)Lenticular mudstone (5G 6/1)Calcareous mudstone (5YR 3/4)Laminated CO3 cemented sandstone (5Y 4/1)Mudstone (5YR 3/2)Lenticular calcareous mudstone (5YR 4/4)Calcareous mudstone (SYR 4/4)Lenticular mudstone (5G 4 / 1 ; N8)Laminated mudstone (5G 4/1)Lenticular calcareous mudstone (5G 6/1)Mudstone (5YR 3/2)Mudstone (5YR 3/2)Laminated mudstone (5G 4 / 1 ; N-3)Laminated calcareous mudstone (5Y 2/1 to 4/1)Lenticular calcareous mudstone (5GY 8/1 to 4/1)Lenticular calcareous mudstone (5GY 6/1 to 4/1)Mudstone (5YR4/1)Lenticular calcareous mudstone (5GY 4 / 1 ; N3)Mudstone (5GY 2/1)Lenticular mudstone (5G 2/6; N3)Laminated mudstone (5G 2/6)Laminated mudstone (5G 2/3)Mudstone (5Y 2/1)Lenticular mudstone (5G 4 / 1 ; N3)Nannofossil limestone (5Y 4/1)Mudstone (5Y 2/1)Lenticular mudstone (5G 4 / 1 ; N3)Laminated mudstone (5G 4/1)Laminated mudstone (5Y 4/3)Laminated calcareous mudstone (5GY 5/1)Mudstone (5Y 2/1)Laminated calcareous mudstone (5G 6/1)Calcareous mudstone (5Y 5/1)Mudstone (5YR 3/1)Mudstone (5Y 2/1)Mudstone (5GY 4/1); some N3 spots)Laminated calcareous mudstone (5GY 5/1)Mudstone (5Y 2/1)Mudstone (5Y 3/1)Lenticular calcareous (5G 6/1)Mudstone (5Y 3/1)Calcareous mudstone (5G 6 / 1 ; N3 lenses)Limestone (5G 7/1)Mudstone (5G 4 / 1 ; N3 lenses)Laminated siltstone (5Y 9/1)Mudstone (5Y 2/1)Lenticular mudstone (5GY 4 / 1 ; N3)Lenticular calcareous mudstone (5G 6/1)Lenticular calcareous mudstone (5G 6/1)Mudstone (SYR 3.5/2)Basalt (velocity of whole core)Basalt (vein) (velocity 0Basalt (velocity of wholBasalt (vein) (velocity 0Basalt (velocity of wholBasalt (velocity of mini-Basalt (velocity of wholBasalt (velocity of mini-Basalt (velocity of wholBasalt (velocity of mini-Basalt (velocity of whol<Basalt (velocity of mini-

mini-core)core)mini-core)core)

core)core)

core)core)

:ore)core)

:ore)Basalt (velocity of whole core)Basalt (vein) (velocity of mini-core)

a Hydrostatic pressure = depth below sea level x 1.035 g / c m ' .b Assumes 40°C/1000 m temperature gradient for simplicity and seafloor temperature of 2.9°C.c Uses Navy SP58 with Table 5. Linearly extrapolated from 35°C to 48°C and assumes 35 ppt.d Uses the velocities measured through the whole basalt core for any velocity-related geophysical calculations. The veloc

whole-basalt core velocities.e These corrections do not include changes in rigidity caused by overburden pressure.

exist. Vane shear measurements were formed adjacentto the sample for velocity, density, and porosity. Bothsets of data appear to be of identical lithology.

On Leg 75, vane shear measurements were done withthe DSDP Wykham Farrance Laboratory Vane Appara-tus. All of the equipment, techniques, and calibrationsare in Boyce (1977) and Boyce (this volume) and won'tbe discussed further here, except for changes from Boyce(1977) and other pertinent information. The 1.263 (high)× 1.278 (diameter) cm vane was used, and it was buriedabout 0.7 cm on top and bottom of the sample. Becauseit was necessary to measure the shear strength on a splitcore (in order to find a proper lithologic sample), thevane was inserted parallel to bedding. The remolded test

ieasured on the basalt i ! used only to dete anisotropy, since these an

was done immediately after rotating the vane ten times(while in the sample).

Other DSDP investigators who have published vaneshear strength are Lee (1973) and Rocker (1974); how-ever, part of these samples are probably seriously dis-turbed. Keller and Bennett (1973) also measured an ex-tensive number of shear strengths; however, the validityof their data is controversial since their cores were, ingeneral, extremely disturbed.

Beginning with DSDP Leg 64, a hydraulic pistoncorer (HPC) was developed which can sample relative-ly undisturbed sediments. Therefore, the vane shearstrengths presented in this chapter will be of speciallyselected, relatively undisturbed portions of these cores.

1144

INDUCTION LOG DATA

RESULTS

The results apply to the laboratory-measured soundvelocity, impedance, gravimetric porosity, gravimetricwet-bulk density, GRAPE two-minute wet-bulk density,shear strength, and their corresponding lithologies,which are in tabulated form in the site summaries (thisvolume). The in situ velocities, calculated from labora-tory data, are in Tables 1 and 2. True formation electri-cal resistivity from the induction log and associated dataare in Table 3. In general, the results apply to the fol-lowing lithologic summary. Detailed discussions are inthe site summaries (this volume).

Lithologic Summary, Site 530

From 0 to 110 m are Holocene to Pleistocene diatomnannofossil ooze and debris flows.

From 110 to 277 m are Pliocene to Miocene nanno-fossil clay, marl, ooze, and debris flows.

From 227 to 467 m are Miocene to Oligocene mud-stone.

From 467 to 600 m are Eocene to Paleocene mud-stone, marlstone, chalk, and clastic limestone.

From 600 to 704 m are Maestrichtian-Campanianmudstone, marlstone, clastic limestone, and calcareoussiliclastic sandstone.

From 704 to 790 m are Campanian mudstone, marl-stone, and calcareous siliclastic sandstone.

From 790 to 831 m are Campanian mudstone, marl-stone and calcareous siliclastics sandstone.

From 831 to 940 m are Campanian to Santonian-Co-niacian mudstone, claystone, siltstone, and sandstone.

From 940 to 1103 m are Santonian-Coniacian to lateAlbian-early Cenomanian claystone with interbeddedblack shale.

From 1103 to 1121 m are basalts.

Lithologic Summary, Site 532

From 0 to 217 m are Pleistocene to Pliocene diatomooze, nannofossil ooze, marl, and clay.

From 217 to 292 m are late Miocene nannofossilooze, marl, and clay.

The following scatter diagrams and figures are pre-sented in order to provide empirical relationships, forcomparison with previous or future studies, and to helpdevelop predictive relationships.

The first scatter diagram (Fig. 2) shows gravimetri-cally determined wet-bulk density versus gravimetricallydetermined porosity for Sites 530 and 532. On this dia-gram, the grain density of each sample may be estimatedby a line from "1.025 g/cm3 (for 35% salinity) densityat 100% porosity" through "the given datum point" tothe "0% porosity axis." The grain density is the bulkdensity value at 0% porosity. This grain density deter-mination is subject to great uncertainty, especially athigh porosity, but at least it allows identification ofsample data of questionable accuracy. Unusual graindensity values could result from laboratory mistakes orfrom gas in the samples.

Figure 3 shows gravimetrically determined wet-bulkdensity versus wet-bulk density as determined by the

GRAPE 2-minute count. Considering all the assump-tions of grain densities and attenuation coefficients, asdiscussed in Boyce (1976a), the correlation of the data isgood.

Scatter diagrams of horizontal and vertical velocityare shown versus gravimetric porosity in Figure 4 andversus gravimetric wet-bulk density in Figure 5. Thesedata are from Sites 530 and 532 and are coded for lithol-ogy. The average of the horizontal and vertical velocityversus gravimetric porosity (Fig. 6) and gravimetric wet-bulk density (Fig. 7) are data from Hole 53OA. Site 532and Hole 53OB did not have any vertical velocity mea-surements; therefore there is no such correspondingscatter diagram (sediment was too soft to measure verti-cal velocity). These figures are coded for lithology.

These figures illustrate the Wood (1941), Wyllie et al.(1956), and Nafe and Drake (1957) theoretical equations(listed in Appendix B), which utilize here, for simplic-ity, a calcium carbonate matrix (6.45 km/s; 2.72 g/cm3) saturated with seawater (1.53 km/s; 1.025 g/cm3).Wood's (1941) equation assumes a suspension of sphereswithout rigidity and theoretically best applies to soft un-consolidated sediment. This equation would tend to givethe lower velocity limit. The Wyllie et al. (1956) equa-tion assumes complete rigidity of the carbonate matrixand should theoretically give the upper velocity limit.The Nafe and Drake equation is shown for n values of4, 6, and 9. No single value of n fits all the data. Forsome values of n, the velocities obtained from the Nafeand Drake (1957) equation may be too high (greaterthan the velocities from the Wyllie et al. equation) ortoo low (lower than the velocities from the Wood equa-tion).

Acoustic impedance is plotted versus vertical velocityGaboratory) for Hole 53OA in Figure 8. The plot ap-proximates a linear relationship and normally segregatesdifferent mineralogies, such as basalt, elastics, lime-stone, and chert, into lines representing different bulkelasticities (Boyce, 1976b; Hamilton, 1976).

Acoustic anisotropy (Fig. 9) is important for estimat-ing vertical velocities (for seismic reflection profiles)from (1) the horizontal velocities determined by refrac-tion techniques, and (2) oblique velocities determined bysonobuoy techniques. Acoustic anisotropy in sedimen-tary rock may be created by some combination of thefollowing variables, as summarized by Press (1966), Carl-son and Christensen (1977), and Bachman (1979): (1) al-ternating layers with high- or low-velocity materials; (2)tabular minerals aligned with bedding, which create few-er gaps (containing pore water) in a direction parallelto bedding; (3) acoustically anisotropic minerals whosehigh-velocity axis may be aligned with the bedding plane;and (4) foliation parallel to bedding.

Absolute acoustic anisotropy versus depth at Hole53OA is shown in Figure 10 and percentage acousticanisotropy versus depth is shown in Figure 11.

The negative anisotropies from 350 to 400 m appearto be related to a gassy zone (gas is in the recoveredcores and may not be in a gaseous state in situ); there-fore, these negative anisotropies are probably not repre-sentative of in situ anisotropies.

1145

R. E. BOYCE

Table 2. Laboratory sound velocity and calculated in situ velocity, Hole 53OB.


3-2, 113-1157-3, 83-859-2, 133-13510-1, 140-14111-2, 140-14212-3, 10-1214-2, 10-1216-2, 130-13217-2, 125-12718-1, 135-13620-3, 25-2721-2, 25-2725-2, 130-13327-2, 10-1333-1, 75-7735-2, 125-12736-3, 20-2237-1, 55-5741-3, 75-7744-2, 85-8746-2, 10-1247-2, 62-6448-1, 135-138

Depth inhole(m)

10.9327.2335.0338.0043.9048.5055.8065.8070.1573.1583.8586.75

102.60108.80118.95137.15142.00142.75158.35165.35172.40176.32178.95

Compressional-sound velocity

II Anisotropy

Beds Beds | - ± (|-_L)/_L(km/s) (km/s) (km/s) (%)

1.506 — — —1.4891.585 — — —1.482 — — —1.505 — — —1.495 — — —1.513 — — —1.503 — — —1.517 — — —1.497 — — —1.505 — — —1.499 — — —1.5001.5071.586 — — —1.560 — — —1.578 — — —1.535 — — —1.524 — — —1.534 — — —1.500 — — —1.538 — — —1.520

Temp.(°C)

2121212020202020202020202020202020202020202020

Hydrostatica

pressure

(kg/cm^)

480.9482.5483.3483.7484.3484.7485.5486.5487.0487.3488.4488.7490.3491.0492.0493.9494.4494.5496.1496.8497.6498.0498.2

In situtemperature"

( ° Q

3.34.04.34.44.74.85.15.55.75.86.36.47.07.37.78.48.68.69.29.59.810.010.1

a Hydrostatic pressure = depth below sea level × 1.035 g/cm ." Assumes 40°C/1000 m temperature gradient for simplicity and seafloor temperature of 2.9°C.c Uses Navy SP58 with Table 5. Linearly extrapolated from 35 °C to 48°C and assumes 35 ppt." These do not include corrections for changes in rigidity caused by overburden pressure.

From 100 to 467 m, anisotropy irregularly increasesto 10%, with 2 to 5% being typical. From 467 to 1103m, anisotropies are as great as 47% (1.0 km/s). Mud-stone and uncemented sandstone have anisotropies whichirregularly increase with increasing depth from 5 to 10%(0.2 km/s). Calcareous cemented mudstone tends to havethe greatest anisotropies, typically 35% (0.6 km/s).

For Site 530, vertical velocity versus depth (except forHole 53OB, 0-175 meters, where only horizontal veloci-ties were measured because the samples were too soft tomeasure vertical velocity) is displayed in Figure 12. InFigure 12, these velocities are at laboratory temperatureand pressure, and are coded for lithology.

At ~ 60 to ~ 70 m, and at ~ 110 to 230 m, these areseveral debris-flow deposits, which in some cases have aslightly higher velocity than the host sediments.

From 500 to 700 m, the minimum mudstone velocitieshave increasing curve versus increasing depth. This isa function of soft mudstone densities, which have anapproximately linear increase between 500 and 700 m;thus the curved velocity trend is, in general, related toWood's (1941) equation of velocity and density-poros-ity as in Figures 6 and 7 and Figures 4 and 5.

Many of the lithologic boundaries are characterizedby changes in sound velocity—for example, at 110, 277,600, -700, 790, and 1103 m. Many age boundaries oc-cur at horizons of obvious changes in velocity, for ex-ample at 110 m for the Pleistocene/Pliocene boundary;at 420 m for the early Miocene/Oligocene boundary; atabout 465 m at the Oligocene/Eocene boundary; at 600

m at the Paleocene/Maestrichtian boundary; and at 685m, which is near the Maestrichtian/Campanian bound-ary. Of course, these variations coincide with subtlevariations in lithology.

In Figure 13 is shown vertical laboratory velocity (atlaboratory temperature and pressure) versus depth. Al-so included are (1) laboratory velocities which are cor-rected for in situ temperature and hydrostatic pressure,and (2) laboratory velocities which are corrected for hy-drostatic pressure, in situ temperature, and porosity re-bound (expansion when overburden pressure is released).These values do not include corrections for rigidity causedby grain-to-grain overburden pressure (Hamilton, 1965).Porosity rebound corrections are theoretical (Hamilton,1976) and have not been demonstrated to be true.

Averages for the velocity for Hole 53OA have beencalculated, and these results (with assumptions andother details) are published in the site summary (thisvolume). The averages in the upper 467 m of the holeagree fairly well with Sibuefs (see site summary, thisvolume) correlations to the seismic profile. For ex-ample, the uncorrected laboratory average velocity is1.56 km/s, in situ corrected (not corrected for rigiditycaused by overburden pressure) laboratory average ve-locity is 1.61 km/s, and Sibuefs average velocity is 1.59km/s. In the lower portions of Hole 53OA, 467 to 1103m, the laboratory averages do not agree with Sibuefsvelocity; for example, the average of uncorrected lab-oratory average velocities is 2.15 km/s, the average ofthe in situ corrected laboratory velocity is 2.37 km/s,

1146

INDUCTION LOG DATA


In situc

velocityof seawater

Velocity correctedfor hydrostaticpressure andtemperature

Velocity corrected forhydrostatic pressure,

temperature, andporosity rebound"

(km/s) I (km/s) j . (km/s) | (km/s) J. (km/s) Lithology (G.S.A. color number)

1.5441.5461.5491.5501.5511.5511.5521.5541.5551.5551.5581.5581.5601.5621.5631.5651.5671.5681.5691.5701.5721.5731.573

1.5281.5131.6121.5101.5341.5241.5431.5351.5501.5301.5411.5351.5381.5471.6261.6031.6221.5811.5711.5821.5501.5891.571

1.5281.5131.6121.5101.5341.5241.5431.5351.5501.5301.5611.5351.5381.5471.6261.6331.6421.6011.5911.6021.5501.6091.591

Clay (5Y 2/1)Clay (5GY 4/1)Clay (5GY 4/1)Nannofossil ooze (5Y 6/1)Clayey diatom ooze (5Y 3/1)Clayey diatom ooze (5Y 3/1)Diatom nannofossil ooze (5G 6/1)Clayey diatom ooze (5Y 4/1)Clayey diatom ooze (5Y 3/1)Clayey diatom ooze (5Y 3/1)Clayey diatom ooze (5Y 3/1)Clayey diatom ooze (5Y 3/1)Clayey diatom ooze (marl) (5G 4/1)Mottled clayey diatom ooze (5Y 4/1)Mud flow clast: diatomaceous clay (5YR 3/1)Mudflow clast: nannofossil ooze (5Y 6/1)Mudflow clast: mottled clayey nannofossil ooze (5Y 6/1)Nannofossil ooze (5Y 6/1)Nannofossil ooze (5Y 6/1)Laminated nannofossil ooze (5Y 6/1)Mudflow clast: clay (5Y 2/1) (disturbed) (5Y 2/1)Mudflow matrix: nannofossil ooze (5G 8/1) (disturbed) (5G 6/1)Layered nannofossil ooze (5G 6/1)

and Sibuefs average velocity is 2.14 km/s. Sibuefslower velocity depends on the upper basalt horizon cor-relating to the 1.2-s reflector; however, in the Chal-lenger profile over Site 530 the basalt reflector is poor,and is either very weak or much higher in the profile andwith significantly less than the 1.2-s reflection time usedby Sibuet. Sibuefs 1.2-s reflector and seismic correla-tions are with another seismic profile, which does notprescisely cross (off by 2.5 miles) Site 530. As a result ofthese conditions, Sibuefs correlation and velocities aresubjective and perhaps controversial.

It is also possible that the average laboratory veloc-ities are incorrect (as many assumptions are involved),or perhaps that the in situ corrections are not valid, forporosity rebound has not been proved. These velocitydiscrepancies will not be resolved here. To perhaps re-solve this problem we need good seismic profiles whichtruly pass over Site 530, along with research to sub-stantiate porosity rebound and additional studies ofacoustic attenuation in these seismic profiles.

Horizontal uncorrected velocities of the laboratorysamples are plotted versus depth for Site 530 (Fig. 14A)and Site 532 (Fig. 14B). These are coded for lithology.Figure 15 shows (1) the uncorrected laboratory horizon-tal velocities versus depth at Site 530; in addition, it alsoshows (2) laboratory velocities corrected to in situ tem-perature and hydrostatic pressure, and (3) laboratoryvelocities which are corrected for in situ temperature,hydrostatic pressure, and porosity rebound. These arenot corrected for rigidity caused by overburden pres-sure.

Gravimetric wet-bulk density is plotted versus depthfor Site 530 (Fig. 16A) and 532 (Fig. 16B), and gravi-

metric porosity is plotted versus depth at Site 530 (Fig-ure 17A) and Site 532 (Figure 17B). These are coded forlithology. These data show good agreement with thesummary in Hamilton (1976) for density versus depthcurves of terrigenous uncemented mudstone and unce-mented siliceous and calcareous ooze. There are twozones of relatively higher porosity and relatively lowerdensity than predicted by Hamilton's (1976) density-porosity versus depth curves (for terrigenous sediment):at approximately 325 to 500 m and at approximately 810to 1025 m; these could be zones where pore fluids areoverpressurized, the result of low-permeability mud-stoned preventing pore fluids from escaping as overbur-den pressure of the grains attempts to consolidate thesediment. However, these zones are probably related tovariations in grain-size distribution and variations in li-thology (Hamilton and Menard, 1956; Horn et al., 1969;Hamilton, 1980).

Cross plots of laboratory velocity (V) versus acousticimpedance (7) for the interval of 625 to 945 m in Hole53OA are shown in Figure 18. From these data, Equa-tion 7 is derived:

I = - 1.9 (g 105)/(cm2 s) + (3.0 g/cm3) (F)

Equation seven (7) is used to calculate impedancefrom the velocities measured by the Sonic Log from 625to 945 m in Hole 53OA. The Sonic Log derived acoustic-impedance data and the reflection coefficient plots ver-sus depth are shown in Figures 19 and 20. In Figures 19and 20, the Sonic Log velocities are low compared to thevelocities of the core samples, as discussed in the sitesummary, this volume. These velocities are more than

1147

R. E. BOYCE

Table 3. Electrical resistivity, formation factors, and sound velocity data from the well logs and other associated data, Hole 53OA.

Depthfrom rig

floor(m)

527452825294.55307.55341535653605366.553725382.55447.55454.5546755235524

Depthbelow

seafloora

(m)

629637649.5662.5696711715721.5727737.5802.5809.5822878879

Depthbelow

sea level*3

(m)

526452725284.55297.55331534653505356.553625372.55437.55444.5545755135514

Hydrostaticpressure0

(kg/cm2)

544.8545.7546.9548.3551.8553.3553.7554.4555.0556.1562.8563.5564.8570.6570.7

Salinityof porewaterd

(%)

34.134.134.134.34.34.34.34.34.34.134.134.134.134.134.1

Temperaturee

(°C)

28.128.428.929.430.731.331.531.732.032.435.035.335.838.038.1

In situPore water

Resistivity,Rw

(ohm-m)

0.17620.17070.17350.17200.16810.16640.16590.16530.16450.16340.15660.15580.15460.14930.1491

Conductivity,Cw

(m-mhos/m)

567758595761581359496009602960506080612063866417646866986708

Boreholediameter

(in.)

11.311.211.211.111.311.511.311.411.211.2511.011.2511.1511.310.8

(cm)

28.728.428.428.228.729.228.729.028.428.627.928.6128.328.727.4

True formation (hole andbed thickness corr.)

Resistivity,Rt

(ohm-m)

2.00(?)2.403.051.521.541.611.371.712.501.292.902.611.731.70(7)1.40(?)

Conductivity,Q

(m-mhos/m)

500417328656651620737584400773345383578588714

j* Depth below rig floor (on logs) - 4645 m = depth below seafloor." Depth below sea level = depth below seafloor plus water depth (4635 m).c Hydrostatic pressure = depth below sea level × 1.035 g/cm .d Salinity of 34.1 ppt is extrapolated from pore-water samples.e Temperature assumes a 40°C/1000 m temperature gradient and a seafloor temperature of 2.9°C.

the laboratory velocities where the hole is washed out.See Figure 1 in Boyce (this volume) which shows whichvelocities in Figures 19 and 20 are valid for a given holediameter. These log-derived reflection coefficients agree,in general, with the major features of Sibuefs correla-tion of Hole 53OA to the seismic profile in the site sum-mary (this volume).

Figures 21 and 22 show reflection coefficients versusdepth (from 0 to 1121 m), which are derived using onlythe laboratory velocity-impedance data. The followingdiscussions ignore requirements of the proper bed thick-nesses for reflectors in a seismic profile.

Of course these show a greater number of potentialreflectors than do the Sonic Log-derived reflection coef-ficients. This is because the Sonic Log data are a rollingaverage over a 1.0-m interval (0.5 meter above and 0.5meter below the calculated value), and because of thetooFs movement up and down in the hole. The toolmoves vertically depending on all movements of theD/V Glomar Challenger and the drill string.

Those reflectors in the upper 100 m of Hole 530A,in Holocene-Pleistocene diatom ooze and nannofossilooze, are caused mainly by density variations, since sed-iment velocities are approximately the same as those ofthe interstitial seawater (excluding the debris-flow de-posits). These density variations can be a function of (1)grain density, e.g., opal silica versus calcite, and (2)porosity variations. In Figures 4 and 5, note that wheredensities are less than 1.52 g/cm3 and porosities aregreater than 71%, the velocity is relatively constant andapproximates that of the interstitial seawater. This zonein Figures 4 and 5 approximately represents the upper100 m of the hole (disregarding debris-flow deposits).The data roughly follow the Wood (1941) equation,which has been shown to be approximately valid bymany investigators (Shumway, 1960; Nafe and Drake,

1963; and others). Reflection coefficients versus depthin Figure 22 indicate that the mudstone from 277 to 467m does not have very many reflectors; if they exist, theywould be very weak. However, below 467 m the carbon-ate-cemented sandstones (limestone) and cemented mud-stones create strong reflection coefficients.

The upper basalt contact at 1103 m does not appearto have significantly stronger reflection coefficients thando the carbonate coefficients above; however, its geom-etry (thick unit) would certainly be conducive to its be-ing a significant reflector. Reflection cofficients of ba-salt below 1103 m are, however, very small; thus theseismic profiles here do not show reflectors below theupper contact of the basalt complex, unless there are in-terbedded lower velocity pillow basalts or sediments.

In Table 3 is the true formation resistivity, in a direc-tion parallel to bedding, calculated from the InductionLog data, plus sound velocity (vertical) from the SonicLog. These logs are from 625 to 945 m in Hole 53OA.Table 3 also contains other associated parameters anddata.

In Figure 23 is plotted velocity, from the Sonic Log,versus true (borehole corrected) formation electrical re-sistivity (parallel to bedding) from the Induction Log.The Velocity Log data are probably biased too low; thusthis cross-plot does not show a valid relationship.

Figure 24 shows vertical laboratory velocity versusgravimetric porosity from 625 to 945 m in Hole 53OA.From these data (Fig. 24) the following empirical rela-tionship (Equation 3) is derived:

Φ =0.527

Equation 3 is used to calculate porosity from the SonicLog for comparison with resistivity from the Induction

1148

INDUCTION LOG DATA

Table 3. (Continued

GRuncorrected

(sonic)(API units)

3888

18151517121816107

1414

Velocityµs/ft.

159.9139.598.6

176.6187.5162.6184.0154.9117.8177.9126.7142.7151.0136.3165.1

In situ pore-water i

km/s

1.9062.1853.0921.7261.6251.8751.6571.9682.5871.7132.4062.1362.0192.2361.846

esistivity

Φ(derived

from Vp)h

(%)

50.539.020.261.068.352.165.947.528.361.932.540.745.337.353.7

Estimatedlithology

from GR logß

3.219.319.319.351.641.941.948.432.351.645.225.816.138.738.7

is extrapolated from U.S. NavyTechniques of Horne and Frysinger (1963ty of Sea Water, U.

): [Anonymous, 1956

FRt/Rw)

11.3514.0617.588.849.169.688.26

10.3415.207.89

18.5216.7511.1911.399.39

2 fi

Φ — /1\ /

29.726.723.933.633.032.134.831.125.635.623.224.429.929.632.6

Lithology of cores

Mudstone with limestone interbedsMudstone with limestone interbedsMudstone with limestone interbedsMudstone with limestone interbedsMudstone and marlstoneMudstone and marlstoneMudstone, marlstone and sandstoneMudstone, marlstone and sandstoneMudstone, marlstone, sandstone and limestoneNo recovery (probably as above)Siliclastic sandstone and mudstoneSiliclastic sandstoneSiliclastic sandstoneClaystoneClaystone

Hydrographic Office SP-11, 1956, and corrected for pressure using, Tables for Rapid Computation of Density and Electrical Conductivi-

S. Navy Hydrographic Office, Special Publ. 11].nop nf ^—^^ Δ"PT unite* thprpfrirp Actimαtf* r\f r\r*rnr*ritα<TP Mct\r GR-2 v i m

0.528 33-2, where V = velocity in km/s.

Log in order to solve for an apparent interstitial waterresistivity (Rwa) curve versus depth. The Sonic Log hadto be used for this purpose because the Density Log at-tempts were unsuccessful as a result of poor hole condi-tions.

Figure 25 shows the formation factor (from Table 3)versus porosity derived by using Equation 3 with veloc-ity from the Sonic-Log data. Note that many of the mvalues appear to be too high (greater than 2.6) relativeto equations in Appendix A. These m values may beartificially too high since they are based on biased data.The bias probably results from the fact that the velocityobtained from the Sonic Log is too low; thus the derivedporosity (Equation 3) is too high for a given true forma-tion resistivity value.

The Rwa curve (Fig. 26) is calculated by rearrangingthe Archie (1942) equation: Rwa = (Resistivity Induc-tion Log) (Φ2), where Φ is the fractional-porosity derivedfrom Sonic Log (Equation 3). Rwa is plotted versus depthand is used here mainly as a tool to identify zones of: (1)metallic mineral deposits, (2) temperature anomalies,(3) interstitial-water salinity anomalies, and (4) hydro-carbons. It is not designed to calculate Rwa accurately(borehole corrections are not applied), but only to indi-cate the presence of anomalous lithologic zones.

In Figure 26, there are no large anomalies (unfortu-nately, the logging data are above the black shale beds),and the variations seen are noise in the data: (1) slightmisalignment of the depths of the velocity and Induc-tion Log data; (2) thin beds with contrasting resistiv-ities, since the Induction Log resistivities were not ad-justed for borehole conditions; and (3) the 1.2-m resolu-tion of the Induction Log relative to the 61-cm vertical

resolution of the Velocity Log. Theoretically the Rwa

plot should decrease slightly with increasing depth be-cause of increasing temperature.

Vane shear strength versus depth is shown in Figures27 and 28 (coded for lithology) for Sites 530 and 532(Holes 532 and 532B). Many of these samples, particu-larly those below 130 m at Site 532, are gassy; thus thevane shear strength may be less than that of comparablesediments which are water saturated, and partially theresult of disturbance of sediment as gas expands (Doveret al., 1981). Vane shear strength of gassy samples maynot represent in situ conditions, for the sediments maynot contain gas at in situ depths. From 0 to 100 m, vaneshear strength uniformly increases from about 80 g/cm2

to about 800 g/cm2. From about 100 to about 300 m,vane shear strength varies irregularly with increasingdepth, ranging from about 500 to 2300 g/cm2. At Site532, vane shear strength actually decreases slightly withincreasing depth (disturbance of sediment by expandinggas), which agrees with similar data at Site 362 (Bolliand Ryan et al., 1978). Vane shear strength at Site 362tended to be significantly less than at Site 532, probablyas a result of the disturbance of Site 362 cores by rotarycoring methods; it is also possible that these sedimentsare significantly different from those at Site 532.

In Figures 29, 30, and 31 are presented vane shearstrength versus gravimetric porosity, gravimetric wet-bulk density, and horizontal sound velocity. These arecoded for lithology. In these plots some grouping doesoccur; however, this probably results, in part, from alimited number of data for each lithologic type—e.g.,siliceous ooze in Figures 29 and 31—which relate vaneshear strength to porosity and velocity. In the vane

1149

R. E. BOYCE

10 20 30 40 50 60Gravimetric porosity (%)

70

Figure 2. Gravimetrically determined wet-bulk density versus gravimetrically determined porosity, Sites530 and 532.

strength-density plot (Fig. 30), the siliceous sedimentsare distinctly set apart from the other data; this is in partcaused by its lower grain density of opaline silica.

The high-porosity siliceous (diatoms) sediment ap-pears to have distinctly higher values for vane shearstrength for a given porosity than do other sedimenttypes. This is partially related to the structural strengthof the framework of the diatom fossils (Hamilton, 1976).

SUMMARY AND CONCLUSIONS1. At Site 530, from 0 to 100 m below the seafloor in

Holocene to Pleistocene diatom and nannofossil ooze(excluding debris-flow deposits), the sound velocity ofundisturbed samples is approximately equivalent to thatof the interstitial water; thus, reflectors are caused bygrain density changes (e.g., opal silica to calcite) andporosity changes, and not significantly by velocity vari-ations. These low velocities are in theoretical agreementwith Wood's (1941) equation.

2. Reflection coefficients derived from laboratorydata agree in general (at least in the upper part of Hole53OA) with the major features of the seismic profile (see

site summary, this volume). It suggests more potentialreflectors than indicated by the reflection coefficientsderived from the Gearhart-Owen sonic log from 625 to940 m (since the sonic log data average thin beds).

3. From 0 to 467 m, at laboratory temperature andpressures, velocities are 1.5 to 1.8 km/s; below 200 mthese increase irregularly with increasing depth. From 0to 100 m in Holocene to Pleistocene nannofossil anddiatom ooze, velocities are approximately equivalent tothat of the interstitial seawater. From 100 to 467 m, inPliocene-Oligocene nannofossil ooze, clay, marl, mud-stone, and debris flows, acoustic anisotropy irregularlyincreases to 10%, with 2 to 5% being typical. From 467to 1103 m, in Eocene to late Albian-early Cenomanianinterbedded mudstone, marlstone, chalk, clastic lime-stone, sandstone, and black shale, velocities range from1.6 to 5.48 km/s, and acoustic anisotropies are as greatas 47% (1.0 km/s) faster horizontally. Mudstone anduncemented sandstone have anisotropies which irregu-larly increase with increasing depth from 5 to 10% (0.2km/s). Calcareous mudstone has the greatest anisotro-pies, typically 35% (0.6 km/s).

1150

INDUCTION LOG DATA

1.0 1.5 2.0Two-minute GRAPE wet-bulk density (g/cm )

Figure 3. Gravimetrically determined wet-bulk density versus two-minute GRAPE-determined wet-bulkdensity, Sites 530 and 532.

4. In situ velocities are calculated for the laboratory-measured data and are corrected for in situ temperature,hydrostatic pressure, and porosity rebound (expansionwhen the overburden pressure is released); however,they are not corrected for rigidity changes related tooverburden pressure. These corrections affect the semi-consolidated sedimentary rocks most (up to 0.25 km/sfaster). Sonic Log velocities appeared to be less thanlaboratory data.

5. Measurements of porosity-density versus depthfor mud, mudstone, and pelagic oozes agree with thosefor similar sediments in Hamilton's (1976) summary. Inthe area of about 400 m and about 850 m are zones ofrelatively higher porosity for mudstone, which may sug-gest overpressurized pore water; however, they are morelikely to be caused by variations in grain size distribu-tion and lithology.

6. Electrical resistivity, in a direction parallel to bed-ding, from 625 to 950 m, ranged from about 1.0 to 4.0ohm-m in Maestrichtian to Santonian-Coniacian inter-bedded mudstone, marlstone, chalk, clastic limestone,and sandstone. An interstitial water resistivity curve didnot indicate any unexpected lithology or unusual fluidsor gases in the pores of the rocks. These logs were abovethe black shale beds.

7. From 0 to 100 m at Sites 530 and 532, the vaneshear strength on undisturbed samples of Holocene-Pleistocene diatom and nannofossil oozes uniformly in-creases from about 80 g/cm2 to about 800 g/cm2. From100 to 300 m, vane shear strength of Pleistocene-Mio-cene nannofossil ooze, clay, and marl is irregular versusdepth with a range of 500 to 2300 g/cm2; at Site 532 thevane shear strength appears to decrease irregularly andslightly with increasing depth (gassy zone); this is prob-ably an artifact of disturbed sediments caused by ex-panding gas at atmospheric pressure. Because these sed-iments may not be gassy at in situ depths; the values ongassy samples below 130 m at Site 532 are probably notrepresentative of in situ values.

ACKNOWLEDGMENTS

The author wishes to thank Dr. E. L. Hamilton and Mr. A. H.Jageler for reviewing the manuscript. Mr. Tom Birtley developed andran all requested computer plots.

REFERENCES

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, 1947. Electrical resistivity an aid in core analysis interpreta-tion. >4m. Assoc. Petrol. Geol. Bull., 31:350.

1151

R. E. BOYCE

ASTM, 1975. Standard method for field vane shear test in cohesivesou: ASTM Designation: D 2473-72.1975 Annual Book of ASTMStandards, Pt. 19. Natural Building Stones: Soil and Rock, Peats,Mosses, and Humus: Philadelphia (ASTM), pp. 221-324.

Bachman, R. T., 1979. Acoustic anisotropy in marine sediments andsedimentary rocks. J. Geophys. Res., 84(1113):7467-7663.

Bedcher, A. Z., 1965. Electrical anisotropy of clays: Its geological sig-nificance. Int. Geol. Rev., 7:7-10.

Berg, J. W., Jr., 1952. Conductivity study of aqueous kaolin NaClmixtures. Prod. Mon., 16:36-44.

Birch, F., 1961. The velocity of compressional waves in rocks to 10kilobars, Pt. 2. Geophys. Res., 66:2199.

Bolli, H. M., Ryan, W. B. F., and Shipboard Scientific Party, 1978.Walvis Ridge Sites 362 and 363. Init. Repts. DSDP, 40: Washing-ton (U.S. Govt. Printing Office), 183-356.

Boyce, R. E., 1968. Electrical resistivity of modern marine sedimentsfrom the Bering Sea. /. Geophys. Res., 73:4759-4766.

, 1976a. Definitions and laboratory techniques of compres-sional sound velocity parameters and wet-water content, wet-bulkdensity, and porosity parameters by gravimetric and gamma-rayattenuation techniques. In Schlanger, S. O., Jackson, E. D., et al.,Init. Repts. DSDP, 33: Washington (U.S. Govt. Printing Office),931-958.

_, 1976b. Sound velocity-density parameters of sediment androck from DSDP drill Sites 315-318 on the Line Islands Chain,Manihiki Plateau and Tuamotu Ridge in the Pacific Ocean. InSchlanger, S. O., Jackson, E. D., et al., Init. Repts. DSDP, 33:Washington (U.S. Govt. Printing Office), 695-728.

., 1977. Deep Sea Drilling Project procedures for shearstrength measurement of clayey sediment using a modified Wyke-ham Farrance laboratory vane apparatus. In Barker, P. F., Dal-ziel, I. W. D., et al., Init. Repts. DSDP, 36: Washington (U.S.Govt. Printing Office), 1059-1072.

_, 1980. Determination of the relationships of electrical resis-tivity, sound velocity, and density/porosity of sediment and rockby laboratory techniques and well logs from Deep Sea DrillingProject Sites 415 and 416 off the coast of Morocco. In Lancelot,Y., Winterer, E. L., et al., Init. Repts. DSDP, 50: Washington(U.S. Govt. Printing Office), 305-318.

_, 1981. Electrical resistivity, sound velocity, thermal conduc-tivity, density-porosity, and temperature, obtained by laboratorytechniques and well logs: Site 462 in the Nauru Basin of the Pacif-ic Ocean. In Larson, R. E., Schlanger, S. O., et al., Init. Repts.DSDP, 61: Washington (U.S. Govt. Printing Office).

Bullen, K. E., 1947. Introduction to the Theory of Seismology: Lon-don (Cambridge University Press).

Carlson, R. L., and Christensen, N. I., 1977. Velocity anisotropy andphysical properties of deep-sea sediments from the western SouthAtlantic. In Supko, P. R., Perch-Nielsen, K., et al., Init. Repts.DSDP, 39: Washington (U.S. Govt. Printing Office), 555-559.

Christensen, N. I., Hyndman, R. D., Hall, J. M., and Salisbury, M.H., 1979. Seismic velocities, densities, and porosities of basaltfrom DSDP Leg 46. In Dmitriev, L., Heirtzler, J., et al., In-it. Repts. DSDP, 46: Washington (U.S. Govt. Printing Office),383-388.

Christensen, N. I., and Salisbury, M. H., 1975. Structure and consti-tution of the lower oceanic crust. Rev. Geophys. Space Phys., 13:57-86.

Coulomb, C. A., 1776. Essai sur une application des regies de maximiset minimis à quelques problemes de statique, relatifs à Parchitec-ture. Mem. Mathematique Phys., L'Academie Roy. Sci. (Paris),pp. 343-382.

de Witte, L., 1950a. Resistivity and saturation distribution in infiltrat-ed zones of porous formations around drill holes. Oil & Gas J.,49:246-268.

, 1950b. Relations between resistivities and fluid contents ofporous media. Oil & Gas J., 49:120-132.

Donnelly, T., Francheteau, J. Bryan, W., Robinson, P., Flower, M.,Salisbury, M., et al., 1980. Init. Repts. DSDP, 51, 52, 53: Wash-ington (U.S. Govt. Printing Office).

Dover, A. R., Audbert, J. M. E., and Bea, A. G., 1981. Quality insoil borings makes a difference. Oil & Gas J., 79(26): 133-139.

Gregory, A. R., 1977. Aspects of rock physics from laboratory andlog data that are important to seismic interpretation. In Pay ton, C.H. (Ed.), Seismic Stratigraphy—Applications to Hydrocarbon Ex-ploration, AAPG Mem., 36:15-46.

Hamano, Y., 1980. Physical properties of basalts from Holes 417Dand 418A. In Donnelly, T., Francheteau, J., Bryan, W., Robin-son, P., Flower, M., Salisbury, M., et al., Init. Repts. DSDP,51, 52, 53, Pt. 2: Washington (U.S. Govt. Printing Office),1957-1966.

Hamilton, E. L., 1965. Sound speed and related physical propertiesof sediments from experimental Mohole (Guadalupe Site): Geo-physics, 30:257-261.

, 1971. Elastic properties of marine sediments. / . Geophys.Res., 76:579-604.

_, 1976. Variations of density and porosity with depth indeep-sea sediments. J. Sediment. Petrol., 46(2):280-300.

_, 1978. Sound velocity-density relations in sea floor sedi-ments and rocks. J. Acoust. Soc. Am., 63(2):366-377.

1980. Geoacoustic modeling of the seafloor. J. Acoust. Soc.Am., 68:1313-1340.

Hamilton, E. L., and Menard, H. W., 1956. Density and porosity ofsea floor surface sediments off San Diego, California. AAPGBull., 40(4):754-761.

Horn, D. R., Delach, M. N., and Horn, B. M., 1969. Physical prop-erties of sedimentary provinces, North Pacific and North AtlanticOceans. In Inderbitzen, A. L. (Ed.), Deep Sea Sediments: NewYork (Plenum), pp. 417-441.

Horne, R. A., 1965. The physical chemistry and structure of seawater. Water Resour. Res., Second Quarter, 1:263-276.

Horne, R. A., and Courant, R. A., 1964. Application of Walden'srule to the electrical conduction of sea water. J. Geophys. Res.,69:1971-1977.

Horne, R. A., and Frysinger, G. R., 1963. The effect of pressureon the electrical conductivity of sea water. J. Geophys. Res., 68:1967-1973.

Howell, B. F., Jr., 1953. Electrical conduction in fluid saturatedrocks. World Oil, 136(Pt. I):113-116.

Hvorslev, M. J., 1936. Conditions of failure for remolded cohesivesoils. First Intern. Conf. Soil Mech. Found. Eng., 3:51-53.

, 1937. Uber die festigkeitseignenschaften gestorter bindigerboden: Ingeniorridenskabelige Skriftor A, Danmark, Naturvid,Samfund. Copenhagen.

Hyndman, R. D., 1977. Seismic velocity measurements of basementrocks from DSDP Leg 37. In Aumento, F., Melson, W. G., et al.,Init. Repts. DSDP, 37: Washington (U.S. Govt. Printing Office),373-387.

Jones, L. E. A., and Wang, H. F., 1981. Ultrasonic velocities in Creta-ceous shales from the Williston Basin. Geophysics, 46(3):288-297.

Keller, G. V., 1951. The role of clays in the electrical conductivity ofthe Bradford Sand. Prod. Mon., 15:23-28.

, 1966. Electrical properties of rock and minerals. In Clark,S. P. (Ed.), Handbook of Physical Constants. Geol. Soc. Am.Mem., 97:553-580.

Keller, G. H., and Bennett, R. H., 1973. Sediment mass physicalproperties—Panama Basin and Northeastern Equatorial Pacific.In van Andel, Tj. H., Heath, G. R., et al., Init. Repts. DSDP, 16:Washington (U.S. Govt. Printing Office), 494-512.

Keller, G. V., and Frischknecht, F. C , 1966. Electrical Methods inGeophysical Prospecting: New York (Pergamon Press).

Kermabon, A., Gehin, C , and Blavier, P., 1969. A deep-sea elec-trical resistivity probe for measuring porosity and density of un-consolidated sediment. Geophysics, 34:554-591.

Kravitz, F. H., 1970. Repeatability of three instruments used to deter-mine the undrained shear strength of extremely weak, saturated,cohesive sediments. / . Sediment. Petrol, 40:1026-1037.

Lambe, T. W., 1960. A mechanistic picture of shear strength in clay.Am. Soc. Civil Eng., Res. Conf, on Shear Strength of CohesiveSoils (Boulder, Colorado, June 1960), pp. 555-580.

Lambe, T. W., and Whitman, R. V., 1969. Soil Mechanics: New York(John Wiley and Sons, Inc.).

Laughton, A. S., 1957. Sound propagation in compacted ocean sedi-ments. Geophysics, 22:233-260.

Lee, H. J., 1973. Measurements and estimates of engineering andother physical properties, Leg 19. In Creager, J. S., Scholl, D. W.,et al., Init. Repts. DSDP, 19: Washington (U.S. Govt. PrintingOffice), 701-720.

Matthews, D., 1979. Shipboard measurements of seismic velocity,density, and porosity in DSDP Leg 46 basalts. In Dmitriev, L.,Heirtzler, J., et al., Init. Repts. DSDP, 46: Washington (U.S.Govt. Printing Office), 379-382.

1152

INDUCTION LOG DATA

Maxwell, J. C , 1904. Electricity and Magnetism (Vol. 1): Oxford(Clarendon Press).

Moore, D. G., 1964. Shear strength and related properties of sedi-ments from experimental mohole (Guadalupe Site): /. Geophys.Res., 69:4271-4291.

Nafe, J. E., 1963. Physical properties of marine sediments. In Hill,M. N. (Ed.), The Sea (Vol. 3): New York (Interscience), pp.749-815.

Nafe, J. E., and Drake, C. L., 1957. Variation with depth in shallowand deep water marine sediments of porosity density and the veloc-ities of compressional and shear waves. Geophysics, 22:523-552.

Patnode, H. W., and Wyllie, M. R. J., 1950. The presence of conduc-tive solids in reservoir rocks as a factor in Electric Log interpreta-tion. /. Pet. TechnoL, 2:42-52.

Press, F., 1966. Seismic velocities. In Clark, S. P. (Ed.), Handbook ofPhysical Constants. Mem. Geol. Soc. Am., 97:195.

Richards, A. F., 1961. Investigations of deep sea sediment cores, Pt.I: shear strength, bearing capacity, and consolidation. Washington(U.S. Navy Hydrographic Office), Tech. Rept. 63.

Rocker, K., 1974. Vane shear strength measurements on Leg 27 sedi-ment. In Veevers, J. J., Heirtzler, J. R., et al., Init. Repts. DSDP,27: Washington (U.S. Govt. Printing Office), 425-432.

Salisbury, M. H., Donnelly, T. W., and Francheteau, J., 1980. Geo-physical logging in Deep Sea Drilling Project Hole 417D. In Don-nelly, T., Francheteau, J., Bryan, W., Robinson, P., Flower, M.,Salisbury, M., et al., Init. Repts. DSDP, 51, 52, 53, Pt. 1: Wash-ington (U.S. Govt. Printing Office), 705-714.

Schlumberger Ltd., 1972. Log Interpretation Charts: New York(Schlumberger, Ltd.).

Schmertmann, J. H., and Osterberg, J. O., 1960. An experimentalstudy of the development of cohesion and friction with axial strainin saturated cohesive soils. Am. Soc. Civil Eng., Res. Conf, onShear Strength of Cohesive Soils (Boulder, Co., June 1980), pp.643-694.

Scholl, D. W., 1963. Techniques for removing interstitial water fromcoarse-grained sediments for chemical analyses. Sedimentology, 2:156-163.

Scott, R. F., and Schoustra, J. J., 1968. Soil Mechanics and Engineer-ing: New York (McGraw-Hill).

Shumway, G., 1960. Sound speed and absorption studies of marinesediments by a resonance method. Geophysics, 25:451-467.

Siever, R., Garrels, R. M., Kanwisher, J., and Berner, R. A., 1961.Interstitial waters of Recent marine muds off Cape Bod. Science,134:1071-1072.

Siever, R., Kevin, C. B., and Berner, R. A., 1965. Composition ofinterstitial waters of modern sediments. J. Geol., 73:39-73.

Thomas, B. D., Thompson, T. G., and Utterback, C. L., 1934. Theelectrical conductivity of sea water. Conseil, Intemat. Explor.Mer., 9:28-35.

Winsauer, W. O., and McCardell, W. M., 1953. Ionic double-layerconductivity in reservoir rock. Trans. Am. Inst. Min. Metall. Pet.Eng., 198:129-134.

Winsauer, W. O., Shearin, H. M., Jr., Masson, P. H., et al., 1952.Resistivity of brine-saturated sands in relation to pore geometry.Am. Assoc. Pet. Geol. Bull., 36:253-277.

Wood, A. B., 1941. A Textbook of Sound: New York (MacMillan).Wu, T. H., 1966. Soil mechanics. Boston (Allyn and Bacon).Yong, R. N., and Warkentin, B. P., 1966. Introduction to Soil Behav-

ior. New York (Macmillan).Wyllie, M. R. J., 1955. Role of clay in well-log interpretation on clays

and clay technology. Bull. Calif. Div. Mines Geol., 169:282-305.Wyllie, M. R. J., and Gregory, A. R., 1953. Formation factors of un-

consolidated porous media: Influence of particle shape and effectof cementation. J. Pet. TechnoL, 198:103-110.

Wyllie, M. R. J., Gregory, H. R., and Gardner, L. W., 1956. Elasticwaves in heterogeneous and porous media. Geophysics, 21:41-70.

Wyllie, M. R. J., and Southwick, P. F., 1954. An experimental in-vestigation of the S.P. and resistivity phenomena in dirty sands. J.Pet. TechnoL, 6:44-57.

Date of Initial Receipt: August 31, 1981

APPENDIX AElectrical Formation Factor-Porosity Relations ofWet-Saturated Sedimentary Rock and Sediment1

Maxwell (1904) theoretically derived the following relationship fora suspension of spheres:

F =20

where F = R0/Rw = formation factor; Ro = the electrical resistivityof the saturated formation; Rw = the resistivity of the interstitialwater; and 0 = the porosity expressed as a fraction or decimal.

Archie's (1942) equation was derived for consolidated sandstonewithout clay material:

F=Φ~m Φ~2

where m is a variable depending on consolidation, textures, and ce-mentation.

Winsauer et al. (1952) derived a slightly different empirical formu-la for various sandstone formations:

F = a0- m =O.62 0 - 2 1 5

where a and m are variables depending on cementation, textures, andmineralogy of the formation.

Boyce (1968) derived the following empirical equation for modernmarine diatomaceous silty clay to silty sand (this equation is of thesame form as that of Winsauer et al., 1952):

F= 1.300-145

Kermabon et al. (1969) derived the following empirical equation(one of three), also for modern marine clays and turbidite sands:

• = (1A5

\ Φ

1.46)

APPENDIX BTheoretical Equations Relating Compressional Velocity of the

Wet-Saturated Rock to the Velocities and Densities of theFluid and Solid Grain-End-Member Constituents

The Wood (1941) equation applies to velocities through suspen-sions without rigidity:

1

[Φß - Φ)ßg) (ΦQW + (1 - Φ)Qg

where V = compressional velocity; ρ = density, ß = compressibility,and subscripts g, w, and b represent the solid grains, intersititial wa-ter, and wet-bulk rock or sediment, respectively; and Φ = fractionalporosity, where ρb = ΦQW + (1 ~Φ)Qg•

The Wyllie et al. (1956) equation applies in rocks with rigidity:

The Nafe and Drake (1957) equation applies to rock with varyingdegrees of ridigity, which is controlled in the equation by the value of

β* Qb

Keller (1966) and Keller and Frischknecht (1966) summarize and discuss similar equa-tions derived for continental formations.

1153

R. E. BOYCE

5.0

4.0

3.0

2.0

1.0

0 Siliceous ooze and chertO Calcareous ooze, chalk, and limestone

<£> Clay, claystone, mud, mudstone, and COo cementedD Sand, sandstone, and COo cementedΔ Marl and marlstoneiV Basalt

Open symbols = horizontal velocitySolid symbols = vertical velocity

I

SJ o

90 80 70 60 50 40Gravimetric porosity (%)

30 20 10

Figure 4. Laboratory horizontal and vertical velocity versus gravimetrically determined porosity, Sites 530and 532.

1154

INDUCTION LOG DATA

0 Siliceous ooze and chert

O Calcareous ooze, chalk, and limestone

<C> Clay, claystone, mud, mudstone, and COg cemented

D Sand, sandstone, and COo cemented

Δ Marl and marlstone

"fr Basalt

Open symbols = horizontal velocity

Solid symbols = vertical velocity

11.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8

Gravimetric wet-bulk density (g/cm )

Figure 5. Laboratory horizontal and vertical velocity versus gravimetrically determined wet-bulk density,Sites 530 and 532.

1155

R. E. BOYCE

ε *

i


< > Clay, claystone, mud, mudstone, and COg cemented

D Sand, sandstone, and COg cemented


•fr Basalt

Wyllie et al. (1956)

Wood (1941)Nafe and Drake (1957)

n = 9

90 80 70 60 50 40

Gravimetric porosity (%)

30 20 10

Figure 6. Average of laboratory horizontal and vertical velocity versus gravimetrically determined porosi-ty, Hole 53OA. Included are equations of Wood (1941), Wyllie et al. (1956), and Nafe and Drake(1957), assuming a limestone matrix (2.72 g/cm3, 6.45 km/s) with seawater (1.025 g/cm3, 1.53 km/s)in the pores.

1156

INDUCTION LOG DATA

O Calcarious ooze, chalk, and limestone^ > Clay, claystone, mud, mudstone, and COg cementedD Sand, sandstone, and CO3 cementedΔ Marl and marlstone"fr Basalt

Wyllie et al. (1956)Wood (1941)Nafe and Drake (1957)

n = 9

1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2.0 2.1 2.2

Gravimetric wet-bulk density (g/cm )

2.3 2.4 2.5 2.6 2.7 2.8

Figure 7. Average of laboratory horizontal and vertical velocity versus gravimetrically determined wet-bulk density, Hole 53OA. Included are equations of Wood (1941), Wyllie et al. (1956), and Nafe andDrake (1957), assuming a limestone matrix (2.72 g/cm3, 6.45 km/s) with seawater (1.025 g/cm3,1.53 km/s) in the pores.

1157

R. E. BOYCE

5.5

5.0

4.5

4.0

δI 3.5

Jβ

3.0

2.5

2.0

1.5 -

O Calcareous ooze, chalk, and limestoneO Clay, claystone, mud, mudstone, and COg cementedD Sand, sandstone, and COo cementedΔ Marl and marlstoneit Basalt

§> o

D

α

Dolomitic

0 5 10

Acoustic impedance (g 10 /cm s)

Figure 8. Laboratory determined vertical velocity versus impedance, Hole 53OA.

15

1158

INDUCTION LOG DATA

5.5

5.0 -

4.5 -

_ 4.0 -

3.5 -

3.0 -

2.5 -

2.0 -

1.5 4

1

oODΔ

-

i i 1 1

Calcareous ooze, chalk, and limestone

Clay, claystone, mud, mudstone, and CO3

Sand, sandstone, and CO3 cemented

Marl and marlstone

Basalt

PT O

A O

^ O

s °

Dα

1

cemented

/

πD

D a

&°

1

α Xu

D

D

1

1 x 1

s D

3 0

-

-

I 1

1.5 2.0 2.5 3.0 3.5 4.0

Horizontal velocity (km/s)

4.5 5.0 5.5

Figure 9. Laboratory vertical velocity versus laboratory horizontal velocity, Hole 53OA.

1159

R. E. BOYCE

Acoustic anistrophy (km/s)

0 0.5

O Calcareous ooze, chalk, and limestone^ ^ Clay, claystone, mud, mudstone, and CO j cementedO Sand, sandstone, and COg cementedΔ Marl and marlstone

Basalt

I Coresgassey

1.0

Figure 10. Absolute acoustic anisotropy versus depth, Hole 53OA.

1160

INDUCTION LOG DATA

100 -

200 -

300 -

400

E 500 -

α.•π

I2

600 -

700 -

800

900 -

1000 -

1100 -

- 1 0

Acoustic anisotropy (%)

10 20 30 40 50

I I I 1

O Calcareous ooze, chalk, and limestoneO ^ Clay, claystone, mud, mudstone, and COo cementedD Sand, sandstone, and COo cementedΔ Marl and marlstone

Basalt

I Cores

gassey

S

D O

D

o

o

<ç>I I I j I I I

Figure 11. Percentage acoustic anisotropy versus depth, Hole 530A.

1161

m

100 Hole 530B horizontal velocity

I I I I I I I I T I I I


O Clay, claystone, mud, mudstone, and COg cementedD Sand, sandstone, and COg cementedΔ Marl and marlstone

Basalt

i i i i i i i i r

D

α

a „ D

D

D

1000 -

1100 -

D D

π

o o ^*>o <x> o *I I I I I I 1_ I L I I I I I I I I I I I I I I I I I I I I I I I l I i i

1.5 1.6 1.7 1.8 1.9 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 5.0 5.1 5.2 5.3 5.4

Laboratory vertical velocity (km/s)

Figure 12. Laboratory vertical velocity versus depth, Hole 530A. (These are at laboratory pressure and temperature. The Hole 53OB velocities from 0 to 200 m are horizontal.)

O Laboratory temperature and atmospheric pressure

• Corrected for hydrostatic pressure and in situ temperature

Δ Corrected for hydrostatic pressure, in situ temperature,

and porosity rebound

Hole 530B data • horizontal velocity

o ‰T^°<2

o o

i I J i i i i i i i i i i i i i i i i i i i i i i i i i i i i

1100

1.5 1.6 1.7 1.8 1.9 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 5.0 5.1 5.2 5.3 5.4 gLaboratory vertical velocity (km/s) c

QFigure 13. Laboratory vertical velocity versus depth, Hole 53OA. The Hole 530B velocities from 0 to 200 m are horizontal. (Shown are velocities at laboratory conditions, corrected for hydrostatic 3

pressure and temperature, and corrected for hydrostatic pressure, in situ temperature, and porosity rebound.) §

I

90

1000

1100

D


O ^ Clay, claystone, mud, mudstone, and CO3 cementedD Sand, sandstone, and CO3 cementedΔ Marl and marlstoneiV Basalt

ü 0

a u DD

Dα

D D

DD

D

f. 100

200

B

Gas

GasΔ

Too much gas tomeasure velocity

300

1.5 1.6 1.7 1.8 1.9 2.0

i i i i

1.5 2.0 2.5 3.0 3.5

Horizontal velocity (km/s)

4.0 4.5 5.0 5.5

Figure 14. A. Laboratory horizontal velocity versus depth at Site 530 at laboratory pressure and temperature. B. Horizontal laboratory velocity versus depth at Site 532 at laboratory pressure andtemperature.

100 -

200 -

300 -

400 -

500 -

V. 600o-9

700

800 -

900 -

1000 -

1100 -

oá•r

_cw& *

θ(5- °θ*c<

-

-

-

o

-I I I

i 1

H«aO@jS

o

1

o

1 1 1 1

ò&J A^ # o

O 0 jj

O <Δo 4

O <2^

•ΔO 9ji95 jtë;oo

1

i

• Δ

é Δ

•jsFJ

^ o

o β ^ πi i i i 1

1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 I

O Laboratory temperature and atmospheric pressureΦ Corrected for hydrostatic pressure and in situ temperatureΔ Corrected for hydrostatic pressure, in situ temperature.

and porosity rebound

O A

O θ Δ P§ 4Λ

O A

o (

^ ooi8

Δ^ c

a JSg

k Δ

OΦ ΔO °4k

o S °^Δo ΔD^Φ^Δ # O Φ °

Δ ° Δ O A ° A

Δ o Φ Δ

• Δ Q | A OΦ O^Φ Δ

^ A ° ^ o Φ Δk % 4 Δ

ΦF „. -• o>. A

VWΔAΔ

1 |

ΦO ΦΔ

O A

* Δ ó> / Δ o A

i i i i i i i i i i i i i i i

i i i i i i i i i i i i i

-

_

-

OAOA

OA #

OA <*OA

-

0^04

O A

O A

αoQ^^A^A1 1 1 1 1 1 1 1 1 1 1 1 1

1.5 2.0 2.5 3.0 3.5Horizontal velocity (km/s)

4.0 4.5 5.0 5.5 a

Figure 15. Laboratory horizontal velocity versus depth at Site 530. (These are at laboratory pressure and temperature, corrected for hydrostatic pressure and temperature, and correctedhydrostatic pressure, in situ temperature, and porosity rebound.)

for

ON(St

δzεo

i

R. E. BOYCE

100

200

300

400

J

S. 500sT3

ES 600

2CO

700

800

900

1000

1100

1.2

Gassy

cores

0

100

200

300

/inn

\ c

" \- \

-

B

\\

I

I

\ Nx

I

^ G

ass

\

r

-

-

I

1.2 1.5 2.0 2.5

Gravimetric wet-bulk density (g/cm3)

0 Siliceous ooze and chert


O Clay, claystone, mud, mudstone, and CO3 cemented

D Sand, sandstone, and CO3 cemented


-& Basalt

Hamilton, 1976 (laboratory)

— — — — — = Terrigenous

— — — = Pelagic clay

— — — ^ = Diatom ooze

2.8

1.5 2.0 25

Gravimetric wet-bulk density (g/cm3)

Figure 16. A. Laboratory gravimetric wet-bulk density versus depth, Site 530. B. Site 532.

1166

INDUCTION LOG DATA

100 -

200 -

300 -

40010 20 30 40 50 60 70


90 100


^ Clay, claystone, mud, mudstone, and CO3 cementedD Sand, sandstone, and CO3 cementedΔ Marl and marlstone"fr Basalt

Hamilton, 1976 (laboratory)

— — — — = Terrigenous

1100 -

0 10 20 30 40 50 60 70 80 90 100


Figure 17. A. Laboratory gravimetric porosity versus depth, Site 530. B. Site 532.

1167

R. E. BOYCE

5.5 -

0 5 10j - o

A c o u s t i c i m p e d a n c e (g IO / c m • $ )

Figure 18. Laboratory vertical velocity versus laboratory impedance from 625 to 945 m, Hole 53OA.

1168

INDUCTION LOG DATA

610

650

700

750

800

850

900

Hole diameter Gamma ray(in.) (API units)

5 10 15 20 0 30i i i I I

Sound velocity(km/s)

3 4 5 6j I

Acoustic impedance(g 105/cm2.s)

10 15 20 -0.8

Reflection coefficient

-0.4 0 +0.4 +0.8

Artifact ofthe hole beingwashed out

9501_ L J I J I

Figure 19. Sonic Log, Sonic Log derived impedance, and Sonic Log-derived reflection coefficients versus depth, Hole 53OA. (Vertical depth scaleexpanded.)

1169

R. E. BOYCE

100

200

300

700

800

900

10001—

Hole diameter Gamma ray(in.) (API units)

5 10 15 20 0 30I I I I I I I I


3 4 5 6I I I I

Acoustic impedance(g-105/cm2 s)

0 5 10 15 20 -0.81 I I I I I I

Reflection coefficient

-0.4I

+0.4 +0.8I

E

+JlapU

IO

Co

A3

400

500

600

_ Drillpipe

_ andcollars

—

—

—

I I I I I I I I I I I I I I I I I I I I I I I I

Figure 20. Sonic Log, Sonic Log derived impedance, and Sonic-Log derived reflection coefficients versus depth, Hole 53OA. (Vertical depth scalecondensed.)

1170

INDUCTION LOG DATA

Laboratory reflection coefficient-0.8 o +0.8

50

100

150

200

250

Seafloor

530B

530A

Laboratory reflection coefficient-0.8 0 +0.8

300

350 -

400 -

£ 450 -

500 -

550 -

300 <- •N 60°

Figure 21. Laboratory derived reflection coefficients versus depth, Site 530. (Vertical depth scale expanded.)

1171

R. E. BOYCE

Laboratory reflection coefficient-0.8 0

600

650

700

750

800

850

900 I -

+0.8Laboratory reflection coefficient

-0.8 0 +0.8900

1100 -

Basalt/sedimentcontact

Figure 21. (Continued).

1172

INDUCTION LOG DATA

-0.8

Laboratory reflection coefficientΔ Hole 530B O Hole 530A

0 +0.8

100

200

300

400

~ 500

T3

I 600

700

800

900

1000

1100

Basaltpebble

Basaltpebble

O

Mudflow clast

?Horizontal velocity

Calcarenite(horizontal

velocity)

& 8- ' Basalt/sedimentcontact

1.5 2.0 2.5 3.0Induction log true-formation resistivity (ohm-m)

Figure 23. Induction Log true-formation resistivity versus Sonic Logvelocity, Hole 53OA, 620 to 880 m (data from Table 3).

o o o o o o o o o o en co α i o o r • ^ < O L O < ? PJ CM r•


V Clay, claystone, mud, mudstone, and COg cementedO Sand, sandstone, and CO3 cemented

Figure 24. Laboratory vertical velocity versus laboratory gravimetricporosity from 625 to 945 m, Hole 53OA.

Figure 22. Laboratory-derived reflection coefficients versus depth,Site 530. (Vertical depth scale condensed.)

1173

R. E. BOYCE

100

10 20 30 50Formation factor

100 200 300 500 1000

Figure 25. Induction Log derived formation factor versus porosity. Porosity is derived from the velocitylog using Equation 3 derived in Figure 24. The dashed line is the Humble equation (Winsauer et al.,1952) and the solid lines are Archie's (1942) equation for different values of m. Note that the m valuesappear to be too high [greater than 2.6)], which could be a result of the velocity from the Sonic Log'sbeing biased too low, particularly in the high porosity formations. If the velocity is too low, then thederived porosity is too large for the high resistivity of the formation, which would cause artificiallyhigh m values. However, these do not seriously disagree with the scatter of data in similar plots(Boyce, 1981).

1174

5Or-

L

100

200

300

700

800

900

1000 L-

Hole diameter(in.)

10 15 20 0I I I I

Gamma ray(API units)


INDUCTION LOG DATA

Induction electrical Apparent interstitialGamma ray conductivity water resistivity(API units) (milli-mohos/m) (ohm-m)

30I

30 1500 0 0 0.2 0.4 0.6 0.8 1.0 1.2_| l l l I I I I

UJ

)

αα>

•o

ttom

-bo

Sub

4 0 0

5 0 0

6 0 0

Data— collected

throughdrillpipe

— andcollars

-

J I J I

Figure 26. Sonic Log Caliper, Sonic Log Gamma Ray, Sonic Velocity, Induction Log Gamma Ray, Induction Log Electrical Conductivity, and ap-parent interstitial water resistivity versus depth, Hole 53OA.

— 100

I 200

300 -

O '

*° iCracked

Cracked

O

Cracked

Cracked

_

$ *V

o °o

o

I

ΔMudflow

o

O^ S Δ

I

I

<S>

I

1

Mudflow

\

o

o<> -1

500 20001000 1500

Vane shear strength (g/cm3)

0 Siliceous ooze O Clay, claystone, mud, mudstoneO Calcareous ooze, chalk Δ Marl

Figure 27. Vane shear strength versus depth, Site 530.

2500

ü

€ 100Q.α>

•a

:om

•? 200Δ

3>

ass

y

β

1

O

<y ^ ^Δ

ΔΔ

Disturbed? A

A1

1

0

Δ

A

A

A

A

Aj

A\

I I

Solid symbols = gassy samples

j .

Δ Δ

A

h

1 |

0 500 1000 1500 2000

Vane shear strength (g/cm^)

0 Siliceous ooze O Calcareous ooze, chalk Mari

Figure 28. Vane shear strength versus depth, Site 532.

2500

1175

R. E. BOYCE

2500

2000 -

3 1500 -

1000 -

500 -

090

1 1 1 1

0 Siliceous oozeO Calcareous ooze, chalk

« ^ Clay, claystone, mud, mudstoneΔ Marl


Δ

o Δ

o o A

0

.o ° °0 Φ Δoo oo Δ

o o ^

O o <> °1 I I 1

1

o

4

o

i

°AA

AA

Aè>k * Δ

Φ AO

1

A

A Δ

o

A

A

1

oo

o

oo

85 80 75 70

Gravimetric porosity (

65 6 0 55

Figure 29. Shear strength versus gravimetric porosity, Sites 530 and 532.

2000 -

~ 1500 -

f>S

1000 -

500 -

1.2

I I I

0 Siliceous oozeO Calcareous ooze, chalk

i

O Clay, claystone, mud, mudstoneΔ Marl


Δ

0

0 o

Δ

00 a• o

" 0 ^ Δ Q A9 00 © Δ

o o ° noo oO o <9

j i

Δ

O

I

\J

OA

A

I

A

O AA

oo

o0

i

i

o<>A

A

^ o

A o o

A

I

1.3 1.4 1.5 1.6 1.7

Gravimetric wet-bulk density (g/cm^)

1.8 1.9

Figure 30. Shear strength versus gravimetric wet-bulk density, Sites530 and 532.

1176

INDUCTION LOG DATA

2500

2000 -

"ò> 1500 -

1000 -

500

-

-

o

_

Δ

Δ•

oO

i

Φ Siliceous oozeO Calcareous ooze

^ ^ Clay, claystone.Δ Marl

I

, chalkmud, mudstone


O

ΔΔ

0

o<b

0 o °o o o

o o

I

oΔ

o

0 o

<->o

°i

i

o

O

O

Oi

oo

-o

-o

_

—o

i

1.48 1.5 1.55 1.6Horizontal velocity (km/s)

1.65

Figure 31. Shear strength versus laboratory velocity, Sites 530 and 532.

1177

COEFFICIENTS, AND VANE SHEAR STRENGTH · Electrical resistivity (horizontal) from 625 to 950 m...

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Transcript of COEFFICIENTS, AND VANE SHEAR STRENGTH · Electrical resistivity (horizontal) from 625 to 950 m...