26. POROSITY, DENSITY, GRAIN DENSITY, AND RELATED PHYSICAL PROPERTIESOF SEDIMENTS FROM THE RED SEA DRILL CORES1

Frank T. Manheim, Linda Dwight, and Rebecca A. Belastock,United States Geological Survey, Woods Hole, Massachusetts

INTRODUCTION

Representative sediments from each site were chosen forexamination of their dry specific gravity and grain density.The determinations were made by micropycnometer; waterwas used as the displacing medium, and salt correctionswere based on the refractive index measurements oninterstitial water. For saltier brines the "salinities" derivedfrom index of refraction are somewhat too low but, for themost part, are adequate for these corrections. Watercontents are those determined on the archived samplesselected for these studies. They had been kept in coldstorage (4°C) in screw-capped glass bottles with poly seallids or in heat-sealed polyethylene bags for a period ofabout three months.

The purpose of the measurements was to gain sufficientinformation on grain density to permit application of thegeneral information or pattern to the bulk water contentdeterminations on the small syringe samples. Bulk density,porosity, and other properties could then be calculatedwithout using volume measurements from the syringes.Whereas the data from weight loss on drying (bulk watercontent) at 110-120° were considered good, the volumemeasurements are subject to considerable error, especiallyin more consolidated sediments, and are not usable at allfor shales, more consolidated or cemented rocks, andanhydrite.

Detailed comparisons with the GRAPE determinationswere also an objective. The Red Sea cores offer aparticularly good opportunity to test the validity of thesemeasurements, which have been increasingly questioned.

APPLICABLE FORMULAE

Specific Gravity of Dried Sediment

w = (2)

Sp G =a+x - b (1)

where:

Λ: is sample weight (after drying),a is the weight of the water-filled pycnometer, andb is the weight of the sediment-water-filled pycnometer

x in this case is the weight of the sediment plus the driedinterstitial salt. The b term also contains an* plus the driedsalt. Therefore, equation (1) gives the specific gravity ofdried sediment residue.

Correction for salt: Correction for salt can be made in threesteps.

Contribution No. 3194 of the Woods Hole OceanographicInstitution.

where:

W is water content as a percent of bulk weight andw is the weight of water in the initial wet sediment,

corresponding to the weight of x

s =Sw

100-5(3)

where:

5 is the weight of salt in the initial wet sediment,corresponding to x and

S is the salt concentration, expressed in percent, of theinterstitial brine in the sample.

Correction for salt in equation (1) is now given by equation

(4).

X - S(4)

where:

A =a + x ~ b = the volume of dried sediment,(SpG)b = grain density of the sediment at 4°C, or specific

gravity corrected for salt, and(SpG)s = specific gravity of the salt residue, determined to

be about 2.26 for Copenhagen water, in our experi-ments.

Some verbalizations of the equations given may be helpfulsince the volume-density relationships are often confusing.Equation (1) corresponds to weight divided by volume. Theweight of the pycnometer bottle and its contained sedimentweight cancel out of the denominator of the equationleaving only water weight of the full pycnometer bottle lessthe water remaining after the contained sediment displacesits volume. The difference is the weight of the displacedwater. Since most measurements are made at room temper-ature, the fluid weight is divided by its density at themeasurement temperature to give sediment volume. Waterdensity is about .997 at 25°C. Change in volume of solidswith temperature is ignored as insignificant.

To make the salt correction, the ratio of water content(W) to weight of sediment plus salt (100-W) is multiplied bythe dry weight of sediment emplaced in the pycnometer.This gives original water weight (w) corresponding to theemplaced sediment (x) (equation 2). In like manner, thesalt corresponding to x is given by the ratio of saltconcentration of the interstitial water (S) to the weight of

887

F. MANHEIM, L. DWIGHT, R. BELASTOCK

the water alone (100— S) multiplied by the weight ofwater (w) corresponding to x. The interstitial salinity isobtained from actual measurements on board, or, if thesediment comes from intermediate depths, by interpolationinto an interstitial salinity-depth curve.

Equation (4) is obtained by subtracting from the totaldried sediment (x) the corresponding weight of salt fromequation (3). Since, in the denominator, b also contains anx term, x - s cancels out. However, the weight of displacedwater must be decreased by the volume of the salt. This isgiven by s/(SpG)s. For normal (Copenhagen) seawater wehave determined SpGs to be about 2.26, whereas, for rocksalt the specific gravity is given as 2.16 in handbooks.

GRAIN DENSITY DETERMINATION

Specific gravity (grain density) determinations weremade for selected samples from Leg 23 (Table 1). Theresults of the grain density determinations can be inter-preted in the light of specific gravity for the mineral phasesobserved in the Leg 23 samples (Table 2).

The model grain density for most sediments in Sites 225,227, and 228 was on the order of 2.75 if both evaporiticsediments and several unusually light samples wereexcluded. Examination of the mineralogy (Stoffers andHathaway, this volume) of the light samples indicated thatcristobalite and, to a lesser extent, palygorskite wereprobably responsible for the unusually low grain densities.These minerals appear to result from the weathering ofvolcanic ash. The iron-rich and metalliferous mud from Site226 had a specific gravity of 3.02, which is attributable tothe combined presence of iron-montmorillonite, some ironoxide, and metal sulfide phases. Anhydrite was largelyabsent from the samples chosen for pycnometerdetermination.

Many samples from Sites 225 through 228 showedsalt-corrected specific gravities higher than 2.75, ranging to2.88, for the dried sediment. These values exclude evapor-itic sediments, which had specific gravities commensuratewith the local mixture of anhydrite, halite, and otherconstituents. The mineral phases that may contribute to therather high specific gravities include dolomite; iron-richchlorites and, possibly, montmorillonites; pyrite; and heavyminerals resulting from weathering of basaltic rocks, such asamphiboles and pyroxenes, ilmenite and magnetite, and insome cases, goethite. Manganese was generally not prom-inent except in an unusual ankeritic rock in Sample 225-22,CC (Table 1) and in the mineralized black shales in theevaporitic section of Site 228 (Core 39). Dolomite occurs insmall quantities throughout the cores and becomes prom-inent in or just above the evaporitic sequences.

CALCULATION OF POROSITY, DENSITY, ANDOTHER SEDIMENT PROPERTIES

Data on water loss, interstitial salinity, and grain densitypermit calculation of a variety of pertinent parameters.These are given in the formulae below.

S' =SW

(100-5)(5)

where:

S'is salt from the interstitial water, expressed as a percent ofbulk sediment,

W is water loss on heating at 110°-120°C, as a percent ofbulk sediment, and

S is total salt content of brine, expressed as a weightpercent.

D =100 100

(wt. sed. + salt) + W (100-HQ + WSpGa SpGa

(6)

where:

D is the bulk density or weight of bulk sediment/volumeand

SpGa is the specific gravity of dried sediment (includingsalt).

=_ D(W+S'/SpGs)

(100-HQ + W 100 l -SpGa

where:

P is the porosity, or volume of pores (brine-filled)/totalvolume and

SpGs is the specific gravity of the dried salt residue

(8)

where:

B is brine content of bulk sediment (percent).

W= W/(W0-S'-W) (9)

where:

W is water content expressed as a percent of dry weight ofsediment (brine free).

b =S'

(100-RO(10)

where:

b is brine content of the sediment, expressed as a percent ofthe dried sediment (including salt).

The specific gravity of sea salt = 2.26 according topycnometer measurements on dried Copenhagen standardwater. The specific gravity for halite is given as 2.17 or2.16. Accordingly, 2.2 can be substituted for SpGs formost interstitial waters.

Strictly speaking, values of D and P are valid for 4°C,since at that temperature the weight of 1 g of watercorresponds to 1 cm3 volume. At other temperatures, theweight of the water would have to be converted to volumeby dividing by water density, and the specific gravity termswould have to be altered to density at the given tempera-ture. In practice, these changes would not be significantcompared to natural variability of sediments. Moreover, theparameters given here ignore the compressibility of water at

888

PHYSICAL PROPERTIES, RED SEA CORES

depth and measure only the physical properties of thesediment on deck under atmospheric pressure. We canexpect some expansion and reorientation of cores as theyare moved from the abyssal depths to the surface. Thechange in specific volume of seawater having salinity of 40°/oo decreases from .9735 cm3/g at 25°C and 1 atm. to.9706 cm3/g at 40°C and 200 atmospheres (W. Wilson andD. Bradley, cited in Horne, 1966, p. 481). Thus, where W(water loss) is converted to volume in equations (5) through(10), in situ densities of water corresponding to conditionsat depths on the order of 2200 m would reduce volumes forW as calculated for room temperature and normalatmospheric conditions by about .5%. For very concen-trated brines the error would be less.

COMPARATIVE STUDIES

Syringe-volume Based Porosity Values

Past observers have repeatedly noted serious errors inporosity data obtained from volume information gainedthrough use of cutoff, disposable syringes as samplingdevices. Even with care, the syringe samples tend to entrainair pockets or selectively sample softer deformed slushrather than firmer undeformed sediment. This tendency toobtain porosities that are systematically too large becomesprogressively greater with increasing consolidation. Moreconsolidated materials cannot be sampled at all. Table 3illustrates typical scatter of values under relatively optimumconditions. A Physical Properties Panel meeting forJOIDES, May 27, 1971, concluded that the small syringesystem resulted in questionable data and recommended thatit be revised or replaced (Keller, written communication,1971). For the above reasons, no syringe-volume-basedporosities are recorded here.

The Physical Properties Panel also regarded use ofgenerally less than 1-g samples obtained by the small (1cm3) syringes as undesirably small. However, if the seriouserrors associated with reliance on syringe volumes areremoved, experiments performed by the Woods Holeinterstitial water group suggest that the syringe samples orother comparably small samples can yield values thatcompare reasonably well with larger samples in terms ofwater content. This will be demonstrated in the followingsection. The ability to use small samples for water contentdetermination is important because of the convenience andpracticability of weighing aboard a moving ship using asmall-capacity electrobalance.

Water Determination and Derivative Porosity and Values

Weighing tests using the shipboard balances (CahnElectrobalance) show that weighing accuracies of about 1percent relative error or less can be achieved routinelyexcept in high sea states (Keller, written communication,1971; Boyce, unpublished memorandum, 1972). Byutilizing determination of water content by weight lossafter heating at 110°-120°C, studies by the Woods Holeinterstitial water group of Leg 4 samples have shownreasonably satisfactory agreement between water contentvalues obtained from syringe or other small shipboardsamples (usually on the order of 0.5 cm3) and 5-10-gsamples. The latter were carefully packed in small, special

glass jars with conical polyethylene cap liners (Polyseal®)and were sent to the shore laboratory for analysis. Thesamples were taken from the same core section and intervaland lithologic type as the small samples. Results are shownin Table 3. Whereas a few samples predictably show morethan 10 percent difference, most agree within a few percentwater content, and, equally important, no tendency forsystematic bias is evident.

Porosity and bulk density are more useful than watercontent for many purposes, including estimate ofpermeability, diffusion properties, and geophysical proper-ties of sediments. To calculate these using the formulasgiven earlier, the grain density of the solid portion of thesediment and the salinity (total dissolved solid content) ofthe pore fluid are needed. Given these parameters, valuesare obtained whose reliability is governed chiefly by degreeof freedom from disturbance or contamination of theoriginal sample. The small samples are especially valuablehere, for one can use discretion in avoiding obviouslydisturbed, pasty outer sections of cores and select evenrelatively small islands of apparently undeformed material.

Representative lithologies were sampled as noted in thepreceding sections for grain density measurements bymicropycnometer. These were then applied or interpolatedto the full column to provide grain density measurementfor porosity and density calculations (Tables 4 through 8).

Gamma Ray Attenuation Porosity Evaluator (GRAPE)Method for Determining Physical Properties

The theory and practice of shipboard use of the GRAPEdevice have been dealt with in detail in shipboard manualsand in Boyce (in press) and need not be repeated here. Themethod is unquestionably powerful when properlycalibrated and suited to the problem. The question to bedealt with here is its utility and validity as a routinemeasurement under existing shipboard conditions.

The GRAPE measurements are based on a pencil-diameter gamma ray beam directed transversely through acore in its plastic liner, the core moving slowly across thebeam path. As pointed out by Boyce (in press), sources oferror are inherent in existing shipboard practice because theunopened core includes undisturbed sediment, disturbedsediment, drilling slurries, and possibly also air or gas invariable and unpredictable amounts. Only maximumwet-bulk density values and corresponding minimumporosity values are regarded by Boyce as probably valid.Other potential errors include variations in size of corebarrel or liner and mineral properties.

A factor relating to the utility of the method is that theslow scan through the GRAPE detector must be performedbefore the core is cut for lithologic analysis or sampling;hence, where coring is continuous as in the Red Sea, theGRAPE measurement may delay processing of cores for asmuch as several hours.

Finally, the complex calibration and correction systemsrequire computer processing at the Scripps facility underthe supervision of skilled practitioners. To obtaintheoretically accurate porosity and density values graindensity and mineral character information must beseparately determined. In this respect, the GRAPEresembles the water content approach.

889

F. MANHEIM, L. DWIGHT, R. BELASTOCK

TABLE 1Specific Gravity (Grain Density) Determination

Sample

225-1-6, 0-10 cm225-4-6, 116420 cm225-6-3, 80 cm225-13-6, 0-10 cm225-16-3,140-150 cm225-21-3, 0-10 cm225-24225-24-1,135-140 cm225-26-1, 35 cm226-1-2, 0-10 cm226-1227-3-1,18-27 cm227-6-2, 0-10 cm227-14-1, 109-114 cm227-20-3, 0-10 cm227-25-2, 0-10 cm227-27-1, 0-8 cm227-30-1,135-140 cm227-30-1, 135-140 cm227-32-3, 244 cm227-36-2, 46-53 cm227-44, CC228-1, CC228-8-3, 21-53 cm228-12-6,130-131 cm228-18-2, 140-150 cm228-21-2, 140-150 cm228-28-2, 0-6 cm228-33-1228-39, CC229-1, CC229-3, CC229A-5-6, 0-10 cm229A-8-1, 35-37 cm

229A-8-3229A-10-6, 140-150 cm229A-12^, 140-150 cm229A-15-1, 140-150 cm230-1, CC

Test substanceTest substance

Test substanceTest substanceTest substanceIndian Ocean test mud,

washedIndian Ocean test mud,

washedIndian Ocean test mud,

washedIndian Ocean test mud,

washedIndian Ocean test mud,

washedDrying time tests,above sample

Deptha

(m)

9273986

108153179180198

21

247

101153187203228228248282350

06395

144167230269324

9100

74113

117140154177

9

Salinityb(%)

4.134.304.445.205.819.52

15.015.018.125.625.64.725.34

10.118.723.724.024.324.324.525.125.74.558.60

10.412.813.715.217.021.13.924.104.084.21

4.214.204.204.3

5.90

Specific Gravity^Specific Gravity0 (Corrected)

2.7(0.02)2.67(0.04)2.46(0.01)2.73(0.01)2.71(0.02)2.77(0.00)2.93(0.01)2.92(0.01)2.68(0.03)

—-

2.61(0.04)2.74(0.01)2.73(0.01)2.77(0.01)2.74(0.00)2.76(0.01)2.82 (0.02)2.94(0.00)(2.16)2.43(0.01)2.64(0.00)2.75(0.01)2.74(0.02)2.75(0.01)2.73(0.03)2.81(0.00)2.78(0.02)2.74(0.01)2.82(0.01)

2.68(0.00)2.69(0.02)2.69(0.00)2.78(0.03)

2.72(0.01)2.74(0.01)2.75(0.01)2.70(0.01)2.68(0.01)

8.922.652.654.602.315

2.73(0.02)2.69(0.04)2.47(0.01)2.74(0.01)2.72(0.02)2.81(0.00)2.94(0.01)2.92(0.01)2.70(0.03)3.01(0.005)3.02(0.005)2.61(0.04)2.75(0.01)2.76(0.01)2.80(0.01)2.80(0.00)2.79(0.01)2.88(0.02)2.94(0.00)

_2.45(0.01)2.67(0.00)

2.76(0.01)2.76(0.02)2.77(0.01)2.75(0.03)2.82(0.00)2.80(0.02)2.78(0.01)2.84(0.01)

2.69(0.00)2.70(0.02)2.70(0.00)2.79(0.03)

2.72(0.01)2.75(0.01)2.76(0.01)2.71(0.01)

2.69(0.01)

3.82 (poor run-3.65)2.64

2.69

2.69

2.67

2.66

2.6452.672.682.682.692.682.69

Description of Sample

Yellow carbonate mudBuff carbonate mudGray green carbonate mudGray carb. mud w/dk nodulesBuff carbonate clayGray green mudNodular anhydriteShaly anhydriteHard, brittle shaleIron-rich mud (hot brine deep)e

Iron-rich mud (hot brine deep)e

Gray green carbonate mudGray brown carbonate clayDark green carb. shaleGray brn granular carb. shaleDark gray green-brown shaleBrown black shaleBrown dolomitic shaleAnhydriteRock salt (halite)Brown shale, cristobaliticBrown black shale, cristobaliticYellowish carbonate mudGray yellow pasty mudGreen gray carbonate mudGreen gray carbonate mudRed tinged green mudstoneGreen gray-olive, granular shaleGray black shaleDark gray shale, pyriticLight green carbonate mudWelded (carbonate) tuffGreen gray carbonate mudGray, hard carbonate mud, highmagnesian in part ("siltstone")Cemented "siltstone"Green mud, carbonate richGreen carbonate mudGreen carbonate mudGreen mud

Copper powder (handbook 8.92)Quartz (2.66)Quartz (2.66)Molybdenum trioxide (4.52 at 20°C)Gypsum (2.32)Titanium oxide (anatase) 3.84Dried 4 hrs 110-120° C

Decanted with acetone, followed bydrying 4 hrs 1104 20°CDecanted with acetone, followed bydrying 4 hrs 110-120°CDecanted with alcohol, followed bydrying 4 hrs 110-120° CDecanted with alcohol, followed bydrying 4 hrs 110-120° CDrying only, 110-120° C, 1 hrDrying only, 110-120°C, 2 hrDrying only, 110-120°X, 2 hrDrying only, 110-120°X, 3 hrDrying only, 110-120° X, 3 hrDrying only, 110-120° X, 4 hrDrying only, 110-120° X, 4 hr

890

PHYSICAL PROPERTIES, RED SEA CORES

TABLE 1 - Continued

Deptha Salinityb Specific Gravityd

Sample (m) (%) Specific GravityC (Corrected) Description of Sample

Acetone decantedAcetone decantedAcetone decantedAcetone decantedAcetone decantedAcetone decanted

2.682.702.692.702.712.69

Dried 110-120Dried 110-120°Dried 110-120°Dried 110-120°Dried 110-120°

lhr2hr2hr3hr

Dried 110-120°, 3 hr

Note: Weights of sample used for the pycnometer determinations are between 0.1 and 0.5 grams. Values in paren-thesis are spread of duplicate determinations from the mean.

aDepth from sea floor.^Salinity of interstitial water (in percent, rather than the more normal per mil).cRefers to sediment dried at 110-120° C.^Refers to dried sediment corrected for interstitial salt (grain density at 4°C).eLeached free of salt with distilled water.

In the preparation of Tables 4 through 7 and Figures 1through 5, the precise locations assigned to the watercontent samples were related to the computer log ofGRAPE properties and a mean of values 2 cm on either sideof the appropriate locations was employed as "local" valuesfor correlation. The section means are listed together inTable 8 with the local values for comparison. Sincelocations for water content samples were selected forminimum disturbance, it follows that GRAPE values fromsuch areas ought to be more reliable than whole sectionmeans.

Results of Comparison

The Red Sea cores offer one of the most detailedopportunities for studying sediment physical properties yetobtained in the DSDP program. Reasons for this include thefact that continuous coring was mandated, sediments variedin porosity from nearly 80 percent to less than 1 percent,and an intensive effort was made to sample both frequentlyand judiciously. Comprehensive pore fluid data were alsoavailable for the purpose of salt corrections.

The results of the laboratory and GRAPE porositycomparisons shown in Tables 4 through 7 and Figures 1through 5 fully bear out the caveats given by Boyce (inpress). A statistical analysis of the correlations (Table 9)shows a very poor correlation between the two sets of data,taken as a whole. The null hypothesis that the a (intercept)values do not include 0 for the equation, y = a + bx isrejected only for confidence limits off scale on standardstatistical charts (i.e., X3.995) for all sites except 227. Thismeans that there is a significant systematic bias between thedata sets, the GRAPE values being larger.

The Studenfs t test likewise gives a similar result forslope. In spite of the scatter (and hence very large tolerancelimits) only Site 227 yields the possibility of a slopedenoting a 1:1 correlation between GRAPE and watercontent-based porosities at the 95 percent confidence level.

One should bear in mind that, while not necessarilyideal, the water content-based samples have the closestapproach available to valid samples and freedom fromsignificant systematic error. The consistent trends incomposition of interstitial water extracted from sampleschosen in a similar way also lends independent support to

the concept that the geologisfs (geochemisfs) eye candiscern samples free enough from disturbance to minimize(though not invariably eliminate) contamination withdrilling fluid.

In spite of the above, Sites 225, 227, 228, and 229 doshow certain sections (e.g., 45-57 m, 133-170 m in Figure5, Site 225) where correspondence between the two sets ofdata is good. Similar agreements have been observed byother workers in earlier legs and may be partly responsiblefor a reluctance to discontinue the GRAPE measurementsin spite of recurrent questions on their usefulness to theDSDP program.

DISCUSSION AND CONCLUSIONS

1. In the course of the DSDP the disturbance ofphysical properties of sediments has been noted too oftento require detailed documentation here. Both syringe-derived porosities (utilizing volume data) and GRAPE tendto record values heavily influenced by artificial factors inirregular and rather unpredictable ways. They have notyielded reliable or consistent measures of true porosity ordensity of penetrated strata in Leg 23B. We believe thatthey probably have not delivered valid results in most priorDSDP sites. We recognize that the quality of physicalproperty data may be better in those sites where workersespecially concerned or experienced with these propertieshave made special ancillary measurements (e.g., graindensity); have taken special pains with instrumentcalibration; or otherwise attempted to test the validity ofthe measurements. Particularly significant contributions tothe questions of sediment porosity and related parametersinclude work by Gealy and Gerard (1970), Gealy (1971),Bennett and Keller (1973), and Boyce (in press).

One argument for retaining GRAPE measurements in theface of recurrent questions and criticisms is that GRAPEdata "is good except where it is bad." The difficulty withthis argument is that the goodness or badness has beenestablished only with the aid of methods that are inherentlyless subject to some of the known practical difficultiesaffecting shipboard use of GRAPE. These methods arechiefly water content measurements accompanied by graindensity data, or in cases of consolidated or crystallinerocks, total weighing and displacement. If GRAPE values

891

F. MANHEIM, L. DWIGHT, R. BELASTOCK

TABLE 2Specific Gravity of Selected Minerals

Mineral

Carnallite (KMgCl3*6H2θ)

Tachyhydrite (CaMgCl6 12H2θ)Halite

Analcite

Opal (amorphous silica)

Palygorskite

Cristobalite

Gypsum

K feldspar

Montmorillonite (dehydrated)(3.6% fe 2.74)

Kao Unite

Illite

Chlorite (magnesian)(Fe-chlorite, daphnite)

Quartz

Calcite(Magnesite 3.0)

Anorthite

Polyhalite (K2MgCa2(Sθ4)4«2H2θDolomite

Pyroxenes

Amphibole

Anhydrite

Aragonite

Boracite*

Rhodochrosite

Siderite

Sphalerite

Rutile

Goethite (crystalline)

Ilmenite

Pyrite

Hematite

Arsenopyrite

Specific Gravity

1.60

1.672.16-2.17

2.22-2.29

2.2

2.29-2.36

2.32

2.32

2.54

2.53->2.75

2.63

2.64-2.69

2.62(3.09)

2.651

2.715

2.76

) 2.78

2.87

2.8-3.7

2.9-3.55

2.94

2.94

2.95

3.68

3.95

3.9^.1

4.2

4.28

4.65

5.0

5.2

5.5-6

Note: Above values are of minerals noted or possible in Leg23 cores. An asterisk indicates minerals not actuallyobserved or inferred.

can be relied on only when corroborated by other methods,why not stick to those methods?

A second argument recognizes sources of error, butpoints out that these can be reduced by carefully excludingsections based on a study of core photographs and byintroducing special calibrations or corrections. The problemhere appears to be lack of workers with sufficient interestor knowledge to undertake this type of remedial work. Onemight suggest that the time could be better spent in gettingwater content determinations, backed up by adequatenumbers of grain density measurements.

The most serious argument against GRAPE for routinesediment measurement is that if it introduces erroneous or

misleading data into the Initial Reports volume to anyconsistent degree, this negative fact far outweighs anybenefits it may yield, for in the absence of systematic testsfor validity all the porosity measurements from the DSDPare rendered suspect.

2. A new use for GRAPE that might obviate many ofthe current objections may be to make direct measurements(no linear) on calipered samples of hard rocks (Boyce, oralcommunication, 1973). As DSDP explores deeper meta-morphic, consolidated sedimentary or igneous rocks, suchmeasurements might well yield superior porosity anddensity data on difficult materials.

3. The water content and other derived parameters fromthe Red Sea show that consolidation and cementation doesnot proceed smoothly with depth. Hard-cemented layersand relatively unconsolidated materials occur at nearly alldepths. Similar irregular porosities with depth in pistoncores were also found in careful studies from the Chain 100cruise to the Red Sea. These relationships also hold belowbrick-hard anhydrites and rock salt layers: shales cut offfrom further water loss by almost totally impermeable rocksalt may retain abnormal amounts of pore fluid withrespect to their burial depth.

4. A rather pronounced gradation to lower porosities isfound in shaly carbonate strata immediately above theevaporite suite. This may be due to diffusion of dissolvedcomponents from the evaporites (Mg, Ca, SO4, K) andreprecipitation or diagenetic uptake in the overlyingsediments.

RECOMMENDATIONS2

1. Syringe volume and GRAPE determinations ofporosity should be discontinued for unconsolidated orsemiconsolidated sediments.

2. Increased attention should be given to water contentmeasurements by oven heating. Cutoff syringes may still beuseful to obtain samples for this purpose where sedimentsare sufficiently unconsolidated. Sediments should not besampled at rigid intervals, but rather by approximateintervals, the exact site to be determined by changinglithologies and availability of undisturbed samples. Acoding system designating each water content sample asbeing from undisturbed or relatively undisturbed strata,partly or questionably disturbed strata, and badly disturbedstrata should greatly increase the utility and usability of thedata for geological and geophysical purposes.

3. Routine grain density service should be available atScripps to categorize chief lithologies for the purpose ofconverting water content to porosity and density valueswhere assumed values may be questionable.

4. GRAPE equipment might be retained onboard, ifspace is not at a premium, to be employed on selectedconsolidated materials where the appropriate conditions forvalid measurement could be assured.

2Note: These recomendations are restricted to the fundamentalproperties-water content, porosity, and bulk (grain) density-andare not intended to imply the undesirability of other physical orgeophysical measurements.

892

PHYSICAL PROPERTIES, RED SEA CORES

TABLE 3Comparative Determination of (Leg 4) Water Content on Syringe and

Small Shipboard Samples and on Larger (5-10-g) Samples Sealedand Shipped to Shore Laboratory

Hole, Core, Section

23-1-123-3-223-3-323-4-123-4-3 (12)23-4-3(11)24-1-124-4-3

26-1-3

26-3-226-5-327-1-127-1-227-1-627-2-127-2-227-2-327-3-127-3-227-4-127-5-127-5-2

27 A-1-527A-2-327A-3-327A-4-327A4-329-1-329-4-329-9-229-12-629-14-329-17-130-2430-3-330-6-230-11-230-13-130-15-4 (419 m)

Mini Samples(Shipboard Determinations)

493441424140

12.431.1

26.6a

29.823.322.3

3438.741.639.433.440.522.230.027.126.427.4

42.338/26a

3534

41_

64_

6866

393829283131

Shore Determinations(5-10-g Samples)

48.939.7

__

39.5-

8.830.9

31.626.122.3

___

36.9_

30.828.4

_25.3

42.737.237.537.227.9

34.239.061.767.866.567.2

41.935.731.430.833.733.5

Note: From Sayles et al. unpublished data, 1970; Manheim unpublishedmemorandum, 1970. Values in percent bulk sediment.aDifferent lithologic types.

ACKNOWLEDGMENTSWe thank J. C. Hathaway for his assistance and

discussion of the statistical problems.

REFERENCES

Bennett, R. H. and Keller, G. H., 1973. Physical propertiesevaluation. In van Andel, T. H., Heath, G. R., et al.,Initial Reports of the Deep Sea Drilling Project Volume16: Washington (U. S. Government Printing Office), p.513.

Boyce, R. E., 1972. Unpublished memorandum, ScrippsInstitution of Oceanography, La Jolla, California.

, in press. Physical properties—Methods. In Heezen,B. C, MacGregor, I. G.,et al., Initial Reports of the Deep

Sea Drilling Project, Volume 20: Washington (U. S.Government printing office). Appendix (Leg 15 results)I, p. 205-217.

Gealy, E. L., 1971. Saturated bulk density, grain densityand porosity of sediment cores from the westernequatorial Pacific: Leg 7, Glomar Challenger. InWinterer, E. L. et al., Initial Reports of the Deep SeaDrilling Project, Volume 7: Washington (U. S.Government Printing Office), p. 1081.

Gealy, E. L. and Gerard, R. D., 1970. In situ petrophysicalmeasurements in the Caribbean. In Bader R. G. et al.,Initial Reports of the Deep Sea Drilling Project, Volume4: Washington (U. S. Government Printing Office), p.167.

Horne, R. A., 1966. Marine chemistry: New York (Wiley,Interscience), 568 p.

893

F. MANHEIM, L. DWIGHT, R. BELASTOCK

TABLE 4Comparison of Physical Properties for Site 225

Core, Section,Interval (cm)

1-1,1281-2,421-5,451-6, 103-13-23-33-43-4

4-14-24-34-44-5, 854-5, 1084-6

5-1

5-3, 805-4, 1455-5, 1405-65-6

6-1,736-5,1236-6,1138-3, 80

9-394,359-5, 709-6, 60

10-2, 90

11-4

12-1,110

13-4,23134,7013-4,12013-6,50

14-1,10014-1,11214-2, 12714-4, 1014-415-2, 82

16-2, 8016-3

17-2,4017-3,5017-4, 130

18-1,6018-2, 20

19-1,13719-4, 23

20-1,35

21-3, 10

22-5, 50

23-1,13924-124-1, 150

EstimatedDepth (m)

1289

1920222122

23232425262727

27

3032333536

374244

48

48505154

57

75

77

81828486

8788909394

97

106108

115117120

123127

133138

142

153

165

170

179180

H2O (%)(Lab.)

36.934.634.935.328.325.425.226.327.1

34.528.337.938.155.135.040.0

29.8(44.6?)37.839.740.340.927.8

34.835.639.836.4

25.529.540.725.8

27.8

24.0

41.5

38.741.841.825.0

10.328.333.133.731.8

23.0

12.820.4

13.325.112.9

17.325.1

35.335.8

44.3

35.1

25.4

15.1

3.64.1

Porosity (%)(Lab.)

77.773.573.276.6

55.050.2

_-____

71.646.5

-_

49.150.552.1

_54.1

53.652.455.360.6

(58.8)52.567.847.6

54.5

(62.1)

64.7___

65.748.853.070.159.6

-

59.7

56.8(40.9)

49.151.447.6

51.6-

53.063.1

-

-

56.3

33.9

15.5—

(GRAPE)

62.660.260.661.0

52.949.148.850.351.2

60.052.863.563.778.460.465.5

54.5(69.9?)63.565.566.166.752.3

60.761.665.962.6

49.654.866.950.0

52.6

47.5

67.7

65.067.968.048.924.653.258.959.657.546.0

29.342.230.349.129.7

37.649.462.163.0

71.7

63.1

52.336.4

10.712.0

Density(g/cm 3)(Lab.)

1.671.711.701.691.831.891.901.871.85

1.701.831.641.641.391.691.61

1.79(1.54?)1.641.611.611.601.84

1.711.691.621.68

1.911.821.611.901.85

1.94

1.591.641.591.591.912.321.831.741.721.761.95

2.232.012.221.902.242.111.911.701.701.56

1.72

1.94

2.25

2.752.71

GrainDensity(g/cm 3)

2.732.732.732.732.732.732.722.712.71

2.712.712.702.702.702.692.69

2.70

2.702.712.722.722.732.742.742.752.76

2.762.762.762.762.75

2.75

2.75

2.752.742.742.742.742.732.732.732.732.72

2.722.722.732.732.742.752.752.762.782.80

2.81

2.85

2.85

2.942.92

894

PHYSICAL PROPERTIES, RED SEA CORES

TABLE 4 - Continued

Core, Section,Interval (cm)

26-126-1,25

27-127-127-2, 75

29-

EstimatedDepth (m)

198199

206208209

225

H2O (%)(Lab.)

<l.Oa20.7b

1.26a0.56c

9.160.53

Porosity (%)(Lab.) (GRAPE)

<3.046.4

3.81.7

19.8 24.9

1.2

Density(g/cm3)(Lab.)

2.882.01

2.862.22.44

2.2

GrainDensity(g/cm3)

2.942.74

2.932.22.86

2.2

Note: H2O (Lab.) refers to shipboard water content values obtained by oven drying at 110°-120°C. Porosity (Lab.) and Density (Lab.) utilize H2O values and grain density valuesaccording to equations (6) and (7). Porosity (GRAPE) refers to values from gammaattenuation measurements on cores with liners. Values are taken from GRAPE logprintout by taking the mean of samples 2 cm on either side of the measured position ofthe water content samples. Grain densities as determined in Table 1 are extended orinterpolated to intervening lithologies according to shipboard and other laboratory-determined logs. Parentheses denote alternate lithology sampled at interval.

aDense anhydrite.bShale.cHalite rock.

895

F. MANHEIM, L. DWIGHT, R. BELASTOCK

TABLE 5Comparison of Physical Properties for Site 227

Core, Section,Interval (cm)

3-1, 163-1, 148

5-1, 1155-2, 50

6-1,686-1,786-2, 88

8-1, 120

10-2, 145

12-1,14012-2, 91

13-1,25

14-1,78

15-1,101

16-1,10416-2, 30

17-1,11017-2,143

18-1,13018-2, 12818-3,40

19-1,9519-3,4519-3, 15

20-2, 8020-3,100204, 8020-5, 85

22-2, 9022-3224,68

24-6,51

25-2, 39

26-2,115

27-1,40

28-1, 13528-2, 4628-3, 35

30-1,130

32-332-5, 83

36-2, 46-5336-2, 106

44, CC

EstimatedDepth (m)

23

3738

464648

65

76

8284

91

101

109

114115

123125

132134135

141143143

150153155156

160162172

185

187

197

203

213214215

228

248252

282283

350

H2O (%)(Lab.)

35.621.1

21.928.7

22.529.017.8

20.6

21.2

23.218.7

24.2

21.7

25.6

15.118.019.223.220.319.417.5

23.321.418.4

25.314.818.216.4

25.121.119.9

17.8

18.7

17.3

10.0

17.817.819.1

1.0a

0.20.22.43a

22.4b

14.0b

Porosity (%)(Lab.) (GRAPE)

60.242.1

43.753.1

45.154.038.3

42.7

43.6

46.940.2

48.8

45.4

51.3

34.940.1

42.749.1

45.043.640.5

50.247.342.3

53.536.142439.2

53.747.646.1

42.9

44.6

42.2

27.1

43.343.546.0

3.2

0.60.6

6.649.335.0

63.144.5

65.8

45.862.651.5

-

52.7

-

75.2

-

-

36.354.8

68.662.4

42.366.642.0

67.849.756.1

60.449.542.842.5

50.7

42.5

44.3

50.9-

-

52.664.9

-

-

-

-

Density(g/cm3)(Lab.)

1.661.961.951.81

1.961.822.10

2.02

2.01

1.962.081.94

2.00

1.912.192.10

2.071.97

2.042.072.12

1.972.022.10

1.922.212.112.16

1.932.032.06

2.12

2.092.14

2.37

2.132.132.11

2.83

2.22.2

2.781.91

2.16

GrainDensity(g/cm3)

2.612.63

2.662.68

2.712.732.75

2.75

2.75

2.762.76

2.76

2.76

2.77

2.772.77

2.782.78

2.782.782.79

2.792.792.79

2.792.802.802.80

2.802.802.80

2.80

2.80

2.80

2.79

2.812.832.85

2.88

2.22.22.932.43

2.67

Note: See Table 4 for detailed explanations.aDense anhydrite.

Shale, cristobalitic.

896

PHYSICAL PROPERTIES, RED SEA CORES

TABLE 6Comparison of Physical Properties for Site 228

Core, Section,Interval (cm)

1-2, 82

1-4,572-1,682-2, 502-3, 403-1,45

4-1,404-2, 404-3, 100

4-4,1034-5, 805-3, 95

5-4, 123

6-2, 806-3, 140

6-4,70

6-5, 110

6-6,50

7-1,40

7-2,587-4, 747-5, 1007-6,40

8-3, 75

10-6, 67

11-4,85

12-4,135

13-2, 108

14-1,2414-2, 46144, 8115-1,12215-2, 8015-4, 7716-2,1216-3, 2216-5, 7818-8,13619-3,51

20-1,3520-2, 6020-3, 52

21-1,5021-2,6021-3, 2021-4,51

EstimatedDepth (m)

2.32

5.0715.617.018.424.4

24.425.928.0

29.530.8

36.9

38.7

44.346.4

47.2

49.1

50.0

51.4

53.056.258.058.9

63.7

77.1

83.3

92.8

98.5

105.2106.9110.3115.2116.3119.2

124.6125.2129.7

142.36

153.5

155.3156.5158.5

164.5166.1167.2168.5

H2O (%)(Lab.)

28.2

32.024.825.326.1

25.9

37.426.131.8

37.229.8

30.3

24.0

27.136.2

30.4

24.4

22.6

24.7

35.929.826.423.3

20.9

33.4

20.6

19.8

18.6

16.618.119.9

25.721.920.514.420.118.2

14.8

19.3

18.721.016.9

14.823.716.316.8

Porosity (%)(Lab.)

54.8(53.0)57.748.149.550.6

50.4

63.950.761.7

(57.8)63.855.5

58.7(56.2)53.3

(48.0)

52.373.4

(63.1)65.6

(56.5)49.7

(48.7)47.6

(46.2)

56.3(49.2)63.056.051.748.9

(45.9)

44.0

45.5(47.9)

44.6(43.7)42.8

40.9

37.640.143.1

51.846.344.2

33.843.640.5

34.4

42.4

41.545.236.8

35.050.038.038.9

(GRAPE)

44.649.6

66.7

62.848.253.9

59.648.9

55.9

46.0

49.758.9

51.6

43.4

42.8

49.7

47.449.347.439.7

48.3

39.0

39.1

51.4

41.6

42.241.744.7

49.246.247.6

39.048.040.5

66.9

46.4

76.552.532.1

55.947.335.951.6

Density(g/cm3)(Lab.)

1.94(1.84)1.761.931.911.89

1.89

1.661.891.94

(1.77)1.671.81

1.91(1.80)2.22

(1.74)

1.872.03

(1.68)2.16

(1.80)2.04

(1.93)2.10

(1.97)

2.22(1.92)1.691.811.882.20

2.02

1.95(1.95)

2.16(2.03)

2.05

2.08

2.142.102.05

1.902.002.03

2.212.042.10

2.18

2.06

2.082.022.17

2.211.972.182.16

GrainDensity(g/cm3)

2.75

2.752.752.752.75

2.75

2.752.752.75

2.752.75

2.75

2.75

2.752.75

2.75

2.75

2.75

2.75

2.752.752.752.75

(1-98)

2.76

2.76

2.76

2.77

2.77

2.772.772.77

2.772.772.77

2.772.772.772.75

2.75

2.762.762.78

2.802.822.822.82

897

F. MANHEIM, L. DWIGHT, R. BELASTOCK

TABLE 6 - Continued

Core, Section,Interval (cm)

23-1,5023-223-3,16

24-2,10224-3, 28

25-1,6025-2,4254, 60

26-1,13026-1,130-13326-2,16264, 48

27-1,7027-2, 5527-3,110

28-1,2028-2,101284,104

29-1,3929-2, 3530-1, 12030-1, 120304,57304,14030-6, 28

31-3,110314,10

32-2, 8

33-2, 3533-3, 100

34-1,7034-3, 50

35-1,140-15035-1,140-15035-1, 140-150

EstimatedDepth (m)

182.5183.5185.1

143.5144.2

200.6201.5205.1

210.3210.3210.6213.9

218.7220.0222.1

227.2229.5232.5

236.8237.8

246.2246.2250.0250.9252.7

255.10258.6

264.5

269.8272.0277.7280.5

287.4

H2O (%)(Lab.)

11.921.314.7

21.114.213.716.020.6

17.116.213.525.4

13.513.818.1

16.214.315.6

13.414.5

14.613.514.111.412.6

12.515.5

22.0

22.43.9

10.515.1(0.2)1.40.2

Porosity (%)(Lab.) (GRAPE)

29.747.335.2

46.334.3

33.337.745.5

39.638.032.952.8

32.933.541.4

38.134.536.9

32.734.9

35.132.934.128.731.1

30.936.6

47.7

48.311.0

26.936.20.64.20.6

52.4

36.0

47.846.6

44.959.0

54.0

40.730.9

45.841.449.7

(47.6)39.638.9

45.0(70.4)

38.5

40.134.842.2

41.136.5

43.0

42.524.9

(63.9)37.748.7

Density(g/cm3)(Lab.)

2.322.022.22

2.042.24

2.262.182.05

2.152.172.261.93

2.262.252.12

2.172.232.19

2.262.222.222.252.232.322.28

2.282.18

2.00

1.992.702.352.20

2.22.862.2

GrainDensity(g/cm3)

2.822.822.82

2.822.82

2.822.822.81

2.812.812.812.81

2.812.812.81

2.812.802.80

2.802.80

2.802.802.802.802.79

2.792.78

2.78

2.782.90

2.792.79

2.212.932.2

Note: See Table 4 for detailed explanations.

TABLE 7Comparison of Physical Properties for Site 229

Core, Section,Interval (cm)

Hole 2292-1,952-2, 992-2,1052-3, 11024,1252-6, 503-1, 103-2, 853-3,10034,903-5, 253-6,70

4-1,404-3,1204-5,25

EstimatedDepth (m)

47.549.549.651.152.755

93.195.39798.499.2

101.2

102.4106.2108.3

H2O (%)(Lab.)

39.129.034.934.334.334.2

34.936.735.633.628.634.6

25.931.635.3

Porosity (%)(Lab.)

64.653.560.360.159.659.5

60.362.261.058.953.060.0

49.556.660.7

(GRAPE)

_

___-

64.0—

64.7

71.874.277.2

Density(g/cm3)(Lab.)

1.621.811.691.701.711.71

1.691.661.681.721.821.70

1.871.761.69

GrainDensity(g/cm 3)

2.702.702.702.702.702.702.702.702.702.702.702.70

2.702.702.70

898

PHYSICAL PROPERTIES, RED SEA CORES

TABLE 7 - Continued

Core, Section,Interval (cm)

Hole 229A

1-1,1101-2, 941-3,2014,1201-5,801-6,42

2-2,1102-3,11024, 802-5, 73

3-2, 523-2,1353-6, 140

4-2, 14544,504-6, 105

5-3,1015-6,111

6-2, 1406-3, 10064, 1006-5,1406-6, 100

7-3, 807-4,1107-5,1167-6,140

8-1,808-3, 20-30

9-1,609-2, 57

104,12010-6,135

12-1,14012-2,12012-3, 100124,10012-5, 135

13-3,6013-5, 17013-6,10

14-2, 105

15-1, 12015-3, 12515-5,11215-6, 85

16-2,130164,13016-6, 102

18-2,140184, 120

EstimatedDepth (m)

20.121.422.224.725.826.9

30.632.133.334.7

3939.845.9

58.96164.5

6973.6

76.97879.581.482.5

86.888.690.291.9

113.8117

122.7124.1

136.7139.8

150.4151.7153154.5158

163165167

170

111181183185

188191194

205211

H2O (%)(Lab.)

51.241.845.641.741.023.4

24.333.235.232.2

39.038.937.6

32.230.232.5

34.528.9

34.933.935.538.133.7

42.842.733.937.1

30.722.1

15.730.6

30.636.0

32.335.432.932.526.0

31.429.830.7

26.7

29.019.930.227.6

31.330.428.2

18.4(51.6)?

Porosity (%)(Lab.) (GRAPE)

75.367.270.767.166.546.1

59.658.460.657.3

64.564.463.1

57.354.957.6

59.853.3

60.359.361.163.959.3

68.668.659.863.3

56.444.4

34.555.9

55.961.9

57.961.358.658.250.2

56.955.056.1

51.2

54.141.655.652.4

56.955.953.2

39.2(76.2)?

76.372.669.666.260.947.3

61.962.864.760.6

76.579.676.8

60.0

60.2

(62.4)

61.7

62.8

64.8

75.2

63.2

:

77.0

70.4

60.273.7

81.2

62.3

60.4

-

67.7

Density(g/cπP)(Lab.)

1.441.581.521.581.591.93

1.711.731.691.74

1.621.631.65

1.741.781.74

1.701.81

1.691.721.691.651.73

1.571.581.731.67

1.801.97

2.151.79

1.791.69

1.761.701.751.761.89

1.781.811.79

1.88

1.832.051.811.86

1.781.801.85

2.09(1.45)?

GrainDensity(g/cπP)

2.702.702.702.702.702.70

2.702.702.702.70

2.702.702.70

2.702.702.70

2.702.70

2.702.712.722.732.74

2.752.762.772.78

2.792.72

2.742.75

2.752.75

2.752.752.762.762.76

2.762.762.76

2.77

2.772.772.772.77

2.772.772.77

2.772.77

Note: See Table 4 for detailed explanations.

899

F. MANHEIM, L. DWIGHT, R. BELASTOCK

TABLE 8Comparison of GRAPE Values for Porositya

Sample Interval(Depth in m)

Site 2251-1,1.281-2, 1.931-5, 6.461-6,7.61

3-1,19.03-2, (20)3-3, (22)3-4,(22.5)

4-1,(23)4-2, (24.5)4-3,(26)4-4, (27.5)4-5, (29.8)4-5, 30.14-5, 30.54-6, 30.5

5-3, 30.854, 33.05-5, 34.45-6,(35)5-6, (36)

6-1,36.76-5,43.26-6,44.6

8-3, 48.8

9-3, (57)9-4, 58.99-5, 60.79-6,62.1

10-2, 54.5

114,76.5

12-1,78.1

13-6,85.0

14-1,87.014-1,87.114-2, 88.814-4, 90.6

15-2, 97.3

16-2,106.316-3,108

17-2,114.917-3,116.5174,118.8

18-1,122.6

19-1,132.4194, 135.7

20-1, 140.4

21-3, 152.2

22-5, 164.5

23-1, 168.4

24-1,177.5

26-1, 194.3

27-1,(203.7)27-2, 305.3

29-1,(222)

L

77.773.573.276.6

55.050.2

71.671.646.5

49.150.552.1

54.1

53.652.455.3

60.6

(58.8)52.567.847.6

54.5

(62.1)

64.7

65.7

48.853.070.169.6

59.7

56.8(40.9)

49.151.447.6

51.6

53.063.1

-

-

56.3

33.9

15.5-

19.8

-

S

85.770.671.478.8

56.454.250.555.9

62.351.850.751.157.157.157.153.3

50.355.555.153.753.7

53.754.155.1

61.4

47.356.965.250.3

60.7

62.3

65.9

63.7

52.353.360.455.8

53.7

53.251.3

50.652.553.6

54.9

53.565.0

74.1

61.4

52.8

51.5

45.5

44.5

20.939.8

30.8

TABLE 8

Sample Interval(Depth in m)

Site 2273-1,27.23-1,28.5

5-2, 38.0

6-1,45.76-1,45.86-2,47.4

10-2, 75.0

13-1,90.3

16-1,114.016-2,114.2

17-1,123.117-2, 124.9

18-1,132.3

19-1, 141.01903,143.219-3,143.6

20-2,151.320-3, 153.0204, 154.320-5, 155.8

22-2, 160.422-3,(161.8)224, 163.2

24-6, 184.0

25-2, 186.9

28-2, 214.028-3, 215.4

Site 228

2-2, 17.02-3,18.4

3-1,24.5

4-1,24.44-2, 25.94-3, 28.044, 29.54-5, 30.8

5-3, 37.054, 38.7

6-2, 44.36-3,46.464,47.26-5,49.16-6, 50.0

7-1,51.47-2,53.174,56.27-5,58.07-6, 58.9

8-3,63.8

10-6,77.2

114,83.4

124,92.9

13-2, 98.6

- Continued

L

62.144.565.8

45.862.651.5

52.7

75.2

36.354.8

68.662.4

42.3

67.849.756.1

60.449.542.842.5

50.7

42.5

44.3

50.9

52.664.9

44.649.6

66.762.848.253.959.648.9

55.946.0

49.753.951.643.442.8

49.747.449.347.439.7

48.3

39.0

39.1

51.4

41.6

S

59.159.1

61.9

52.452.451.3

51.6

65.2

52.756.8

53.956.6

57.2

67.652.752.7

53.650.648.248.5

45.945.947.7

49.0

58.9

66.860.3

44.549.3

54.1

55.750.751.861.846.9

52.749.3

53.157.254.147.145.9

50.649.448.846.240.7

49.1

44.0

39.8

53.7

44.8

900

TABLE 8-Continued

PHYSICAL PROPERTIES, RED SEA CORES

TABLE 8-Continued

Sample Interval(Depth in m)

14-1,105.214-2,107.0144,110.3

15-1,115.215-2, 116.315-4,119.3

16-2, 124.716-2,126.216-5,129.8

18-1,142.4

19-3, 153.5

20-1, 155.420-2,157.120-3, 158.5

21-1,164.521-2, 166.121-3, 167.2214,169.0

23-1, 182.523-2, (184.2)23-3,185.2

24-2, 193.524-3, 194.3

25-2, 201.6254,205.1

26-1,210.326-2, 210.7264,214.027-1,(218.8)27-2,220.127-3,222.1

28-1,227.228-2, 229.5284, 232.629-1,236.429-2, 237.9

30-1, 246.2304, 250.1304, 250.930-6, 252.8

31-1,255.1314,258.6

32-2, 264.6

33-2, 269.933-3,272.0

34-1, 277.734-3, 280.5

35-1,287.4

L

42.241.744.7

49.246.247.6

39.048.040.5

66.9

46.4

(76.5)52.532.1

55.947.335.951.6

52.4

36.0

47.846.6

44.959.0

54.940.730.9

45.841.449.7

(47.6)39.638.9

45.0(70.4)

33.540.134.842.2

41.136.5

73.0

42.524.9

(63.9)37.7

48.7

S

44.644.145.3

46.447.548.8

47.943.254.3

43.1

43.2

44.645.535.4

43.549.746.750.7

46.843.257.4

51.743.5

48.456.8

50.343.436.6

45.042.543.7

39.539.634.5

37.244.8

38.036.636.635.4

43.635.544.1

39.137.7

38.838.0

55.5

Sample Interval(Depth in m)

Hole 229

3-2, 95.43-5, 99.2

4-1, 102.44-3, 106.24-5,108.3

L

64.064.7

71.874.277.2

S

68.073.774.178.079.8

Hole 229A1-1,20.11-2,21.41-3, 22.214, 24.71-5, 25.81-6, 26.9

2-2, 30.62-3, 32.12-4, 33.32-5, 34.7

3-2, 39.03-2, 39.934, 42.43-6,45.2

4-2, 58.944,61.04-6, 64.5

5-6,73.6

6-2, 76.964, 79.56-6, 82.5

74,88.67-6, 91.9

9-2, 124.1

10-6, 139.8

12-1, 150.412-2, 151.712-5,156.3

13-3, 161.6

14-2,169.5

16-2,187.8

76.372.669.566.260.947.3

61.962.864.760.6

76.579.670.576.8

60.057.760.2

(62.4)

61.762.864.8

75.263.2

77.0

70.4

60.273.981.2

62.3

60.4

67.7

69.666.068.054.855.949.9

63.262.262.463.5

70.970.970.371.4

63.863.559.0

60.5

66.764.365.0

71.669.8

69.8

73.8

66.363.369.1

62.5

69.4

-

aL = local; S = section average. Porositiesare in percent.

901

F. MANHEIM, L. DWIGHT, R. BELASTOCK

TABLE 9Statistical Comparison of Porosities Determined

from Water Content, Grain Denxity (x), andGamma Ray Attenuation (GRAPE) (y)

X

yXV -»

r

n

a

b

h

*br0.975

225

52.3

55.0

9.24

85.3

0.68

41

23.0

0.61

5.52

0.102

4.16

-3.79

2.02

227

45.3

53.9

8.31

69.0

0.57

28

8.9

0.99

12.5

0.273

0.7154

-1.029

2.06

228

42.3

47.4

9.16

83.9

0.30

72

36.0

0.27

4.34

0.100

8.30

-7.35

2.00

229

59.7

67.2

6.88

47.3

0.38

36

39.0

0.49

11.4

0.190

3.42

-2.67

2.03

Note: Correlation between x and y values is eval-uated by Student's t distribution for sample pairsand for slope and intercept for an equation of theform y = a + bx.

~x = mean of x (laboratory-determinedporosities).

y mean of y (GRAPE porosities)n = number of samples.a - intercept.b = slope.S = standard error of x against y.

2(5 ) = variance of Λ: against y.

r = correlation coefficient (percent ofvariance explained by relationshipbetween Λ: and>>, where 1.0 corre-sponds to 100%).

S = standard error of intercept =

F~lx~2

sxy \ «ΣX2 - (ΣX)2

= standard error of slope =

t = confidence coefficient for Student's

t distribution on intercept =

a-0

Vt^ = confidence coefficient for Student's

t distribution on slope =

b-1

V*0 975 = c o n f i d e n c e coefficient expected for

a 2-tailed test at the 95 percentconfidence interval, for indicatedvalues of n.

902

TOO-

PHYSICAL PROPERTIES, RED SEA CORES

P O R O S I T Y {%)

1 0 -

alCD _

20 30

Θ

Θ

Θ ©

Θ

©

©

40 50 60 70 80 90J i i i i

dB

<S>

Θ©

GΘ

•100

•90

•80

70

- 6 0

-50

- 4 0

•30

.1 10LAB

Figure 1. Plot of laboratory and GRAPE porosity values, Site 225. Expanded plot covers area shown in inset lines.

100

903

F. MANHEIM, L. DWIGHT, R. BELASTOCK

P O R O S I T Y (%)

100

Q_

-

-

—

—

-

-

-

--

-

30 40

oo ©

©©

© ©

©GO

©

50 60

©

©©

© © ©©

o

©

1 1 1 1 1 1

70 80 90 1001 1 I

i > i

-100

-90

-80

-70

-60

-50

-40

Oil

—i 1—i—i—r—i 1 r

©

GEJTgε>©

1—i i i i i

.1 1

LAB

Figure 2. Plot of laboratory and GRAPE porosity values, Site 227.

10 100

904

PHYSICAL PROPERTIES, RED SEA CORES

TOO-POROSITY {%)

1 0 -

1 -

.1

9 0 1 0 0

.11

10LAB

(•) approx. value only

Figure 3. Plot of laboratory and GRAPE porosity values, Site 228.

100

905

F. MANHEIM, L. DWIGHT, R. BELASTOCK

100•

POROSITY (%)

et:

1 -

. 1 -

9 10

Θ

Θ

Θ

Θ

ΘΘ

ΘΘ(•) Θ<

<SΘ

ΘQQQ

ΘΘΘ

<‰.

© °Θ

ΘΘ

Θ

-9

-8

-7

-6

-5

-A

.1i r r i i i i

LAB10

Figure 4. Plot of laboratory and GRAPE porosity values, Site 229.

100

906

PHYSICAL PROPERTIES, RED SEA CORES

POROSITY10I

100

©POROSITY (LAB)

HPOROSITY (GRAPE)

20

40

60

100

-120;

140

-160

-180

-200

-220

240

Figure 5. Plot of laboratory and GRAPE porosity values with depth, Site 225.

907