SANDIA REPORT SAND81-1873 Unlimited Release *UC-70 SIPrinted March 1982 SAr

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-Thermal Conductivity, Bulk Properties,and Thermal Stratigraphy of Silicic TuffsFrom the Upper Portion of Hole USW-G 1,Yucca Mountain, Nye County, Nevada

-- Allen R. Lappin, R. G. VanBuskirk, D.-O. Enniss, S. W. Butters,,,F. M. Prater, C. B. Muller, and J. L. Bergosh

Prepared bySandia National LaboratoriesAlbuquerque, New Mexico 871865 and Uvermore, Californi 94550for the United States Department of Energyunder Contract DE-AC04-76DP00789

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sLsued by Sandia National Laboratories, operated for the United StateeDepartment of Energy by Sania Corporation.NOTICE: This report was repared as an account ofwok spnsored by anage=cy of the United States ornmone.t Neither the United States Govern-ment nor any agency thereof, nor any of their n1p , esor any of their - 1i3

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ContentsIntroduction.................................................................................................................................7Test Procedures ............................................................. 7

Sample Preparation and Bulk-Property Measurements .................................................... 7Thermal-Conductivity Measurements ...................... ........................................ 9

Test Results ............................................................. 10Topopah Spring Member, Paintbrush Tuff ............................................................. 11Tuffaceous Beds of Calico Hills (Informal) ............................................................. 11Prow Pass Member of the Crater Flat Tuff ............................................................. 12Bullfrog Member of the Crater Flat Tuff ............................................................. 12Tram Member of the Crater Flat Tuff (Informal) ............................................................. 14

Thermal Stratigraphy .............. 16Conclusions and Discussions ............................................................. 24APPENDIX A-Test Procedures for Sample Preparation and Bulk-Property

Measurements ............................................................. 25APPENDIX B-Test Procedures, Calibration, and Data-Acceptance Criteria

for Thermal-Conductivity Measurements .................................................. 27APPENDIX C-Individual Thermal-Conductivity Test Results .................... .................... 31APPENDIX D-Bulk-Property Measurements ............................................................. 39References ............................................................. 46

Figures1 Index Map of Region Near Hole USW-G1 .............................................................. 92 Theoretical Grain Density-Conductivity Relationship and Calculated K.

Values for Silicic Tuffs From UE25A#1 and USW-G1 ................................................ 19

Tables1 Stratigraphic Intervals and Number of Samples Tested, Upper Portion

of USW-G1 ............................................................. 82 Approximate Thermal-Conductivity Test Conditions .................................................. 103 Summary of Thermal-Conductivity Test Results, Upper Portion of USW-G1 ........ 104 Summary of Thermal-Conductivity Test Results, Central Nonzeolitized

Portion of Bullfrog Member, Crater Flat Tuff ............................................................. 135 Summary of Thermal-Conductivity Test Results, Zeolitized Portion of

Bullfrog Member, Crater Flat Tuff ......................... ..................................... 146 Thermal-Conductivity Test Results, Bullfrog Member, Crater Flat Tuff,

Hole UE25A#1................................................................................................................... 147 Summary of Reliable Thermal-Conductivity Test Results, Nonzeolitized

Portion of Tram Member, Crater Flat Tuff ............................................................. 158 USGS - Terra Tek Thermal-Conductivity Comparison Test Results ............ ........... 159 Calculated Matrix Conductivity (K,) and Air Thermal-Conductivity (Kg)

in Analyzed Samples .............................................................. 1710 Estimated Maximum Effects of In-Situ Thermal Fracturing on Rock-Mass

Thermal-Conductivity of Welded Devitrified Tuffs ..................................................... 2111 Estimated Thermal-Conductivity and Bulk-Property Stratigraphy

(Saturated) of Upper Portion of Hole USW-G1 Below 409.1 m (1342 ft) ................. 2212 Estimated Thermal-Conductivity and Bulk-Property Stratigraphy (Matrix-

Saturated) of Upper Portion of Hole USW-G1 Above 409.1 m (1342 ft) .................. 23

5.6

4.

SAND81-1873 DistributionUnlimited Release Category UC-70Printed March 1982

Thermal Conductivity, Bulk Properties, andThermal Stratigraphy of Silicic Tuffs From theUpper Portion of Hole USW-G 1, Yucca Mountain,Nye County, Nevada

Allen R. LappinNNWSI Geotechnical Projects Division 4763Sandia National LaboratoriesAlbuquerque, NM 87185

R. G. VanBuskirk, D. 0. Enniss, S. W. Butters,F. M. Prater, C. B. Muller, and J. L. BergoshTerra Tek, Inc420 Wakara WaySalt Lake City, UT 84108

AbstractThermal-conductivity and bulk-property measurements were made

on welded and nonwelded silicic tuffs from the upper portion of HoleUSW-G1, located near the southwestern margin of the Nevada Test Site.Bulk-property measurements were made by standard techniques. Ther-7mal conductivities were measured at temperatures as high as 280'C,confining pressures to 10 MPa, and pore pressures to 1.5 MPa.

Extrapolation of measured saturated conductivities to zero porositysuggests that matrix conductivity of both zeolitized and devitrified tuffsis independent of stratigraphic position, depth, and probably location.This fact allows development of a thermal-conductivity stratigraphy forthe upper portion of Hole G1. Estimates of saturated conductivities ofzeolitized nonwelded tuffs and devitrified tuffs below the water tableappear most reliable. Estimated conductivities of saturated denselywelded devitrified tuffs above the water table are less reliable, due to bothinternal complexity and limited data presently available. Estimation ofconductivity of dewatered tuffs requires use of different air thermalconductivities in devitrified and zeolitized samples. Estimated effects ofin-situ fracturing generally appear negligible.

3-4

Thermal Conductivity, Bulk Properties, andThermal Stratigraphy of Silicic Tuffs From theUpper Pottion of HolevUSW-Gi, Yucca Mountain,

Nye County, Nevada

IntroductionThe future of nuclear power depends, in part, on

improved waste management. One option for terminalwaste disposal would require excavation of reposi-tories under land-base sites. Evaluation of potentialrepository horizons at such sites requires extensiveinformation if the in-situ response to heating imposedby the waste is to be predicted. A mathematical modelof the host rock and surrounding units is rquired forthis prediction; the model requires determination ofthe physical, mechanical, and thermal properties ofthe units. At least part of the data must come fromlaboratory tests that duplicate the overburdens, fluidpressures, and temperatures expected to result fromwaste emplacement.

The program of thermal conductivity and physi-cal property measurements described in this reportwas conducted at Terra Tek, Inc, Salt Lake City,Utah. The work was one of several ongoing activitiesaimed at determining the feasibility of siting a nucle-ar-waste repository in tuff either on the Nevada TestSite (NTS) or adjacent to it. This overall effort,

Athe Nevada Nuclear Waste Storage Investigations(NNWSI) project, is administered by the NevadaOperations Office of the US Department of Energy(DOE). The general stratigraphy in the upper portionof Hole G1 is shown in Table 1, as are numbers ofsamples analyzed for thermal conductivity and physi-cal properties. The static water level in G1 is at-564 m (1850 ft) depth.

This report has three main objectives:

* To report thermal conductivities of samples ofsilicic tuffs from the upper portion of HoleUSW-G1 (Figure 1).

* To report general physical properties of theanalyzed tuffs (porosity, grain density, etc) anddetermine how these properties and mineralogyaffect thermal conductivity.

* To develop a thermal-conductivity stratigraphyfor the upper portion of Hole G1 by combiningthe established correlations between bulk prop-erties, mineralogy, and thermal conductivitywith additional bulk-property measurements.

Test Procedures

Sample Preparation and Bulk-Property Measurements

Standard procedures were generally used for sam-ple preparation and bulk-property measurement, andare described in Appendix A. Care was taken to satu-rate samples fully by means of vacuum impregnationwith water before thermal conductivity measure-ments.

Duplicate bulk-properties analyses were per-formed on 39 samples during the course of this study.The average difference between pairs of bulk-densitymeasurements on the same sample is 0.045 g/cm3,with ± 0.044 g/cm3 standard deviation. This indicatesthat measured bulk densities should be precise to± 0.09 g/cmi3 at the one-sigma level of confidence.Similarly, individual dry-bulk densities should be pre-cise to ± 0.1 g/cm3, porosities to ± 0.06, and calculatedbulk densities at full saturation to ±0.06 g/cm3. Theprecision of reported grain densities depends on rocktype. In zeolitic samples, in which the grain density isgenerally 2.5 g/cm3 or less, measurements should beprecise to ± 0.06 g/cm3 . In devitrified zeolite-free sam-ples, measurements appear precise to ± 0.04 g/cm3;grain densities of these samples are generally 2.6 g/cm3

or greater. The reduced precision in zeolitized materi-al appears to be due to the fact that zeolites will

7

partially rehydrate after drying if exposed to air, evenfor a short period of time. Given the simplicity of theindividual steps involved in these measurements, theaccuracy should be of the same order as the precision.Throughout this report, densities and porosities aregenerally reported without associated uncertainties.

Table 1. Stratigraphic Intervals and Number of Samples Tested,Upper Portion of USW-G1 (Stratigraphic intervals taken from Ref 1)

StratigraphicUnit

Quaternary Alluvium

Tiva Canyon Member,Paintbrush Tuff

Yucca Mountain Member,Paintbrush Tuff

Pah Canyon Member,Paintbrush Tuff

Topopah Springs Member,Paintbrush Tuff

Tuffaceous Beds ofCalico Hills (Informal)

Prow Pass Member,Crater Flat Tuff

Bullfrog Member,Crater Flat Tuff

Tram Member, CraterFlat Tuff (Informal)

Depth(m(ft))

0-18.3(0-60)

18.3-30.5(60-100)

30.5-38.1(100-125)

38.1-71.6(125-235)

71.6-434.4(235-1425)

Samples Tested to Date

Thermal BulkConductivity Properties

0 0

0 0

0 0

0 0

2 17

434.4-549.3(1425-1802)

549.3-662.3(1802-2173)

662.3-804.4(2173-2639)

804.4-1084.5(2639-3558)

2 13

2 21

13 51

6 45

8

Explanation

[i~j Alluvium and Colluvium.... ..... ~~~~~~~~~~(Quaternary)

T2 I oTiva Canyon Member36052'.*

USW G1,~~~~~~~~ Yucca Mountain and

IS' X I~ j i Pah Canyon MembersW

.~.....7 jA 1 Topopah Springs Member

36"51' 1 0 'EStrike and Dip

Qal ~~~~~~~~~~~~Fault; ball on downthrown side;

""T t" Qal ~~~~~~dashed where inferred; dottedwhere concealed.

. . ~~~~~~~~~~~0 Drillhole

o Miles 1.0I Boundary of Nevada Test Site

0 Kilometers 1.5

Figure 1. Index Map of Region Near Hole USW-G1 (Simplified from Reference 2)

Thermal-ConductivityMeasurements

Thermal conductivities in this program were mea-sured by a transient-line-source technique,' selectedbecause of its simple application in a pressure-temperature environment. Experimental setup, dataanalysis, calibration, potential problems, and criteriafor data acceptance are discussed in Appendix B.

Frequent calibration with fused silica at bothTerra Tek and other laboratories indicates that theexperimental rig used here is generally capable ofmeasuring conductivities of uniform material having anominal conductivity of 1 to 2 W/m0 C to within± 0.06 W/m0 C or less. Near the boiling of water,

however, anomalously high apparent conductivitiesare measured (see Appendix B). Due to inherent mate-rial variability, measurements on tuff are not as pre-cise or accurate as on the standard. Assumption ofaccuracy to within + 10%7 appears conservative.

Thermal conductivities were measured at approx-imately the temperatures, hydrostatic confining pres-sures, and fluid pressures outlined in Table 2. Theroom-temperature, nonpressurized tests were includ-ed for comparison and to check for possible confining-pressure effects. Subsequent testing was performed atconstant confining and fluid pressure, at increasingtemperatures. Fluid pressure was maintained con-stant at 1.5 MPa in the pressurized tests, which al-lowed the pore fluid to flash to steam and the sample

9

to dehydrate fully at -200'C, before measurement athigher temperatures. At each test condition, duplicatemeasurements were generally made, with -1/2 h al-lowed for the sample to stabilize between tests. If twomeasurements differed by > - 10%, additional mea-surements were made.

Test ResultsResults of conductivity tests are summarized in

this section in downward stratigraphic sequence, andlisted in Table 3. Detailed results of each test are givenin Appendix C. All bulk-property measurements madeto date in each stratigraphic unit are given in Appen-dix D.

Table 2. Approximate Thermal-Conductivity Test Conditions

T(0 C) Ponft,, (MPa) Pfluid (MPa)

23 (Atmospheric) (Atmospheric)23 10 1.5

100 10 1.5165 10 1.5240 10 1.5270 10 1.5

Table 3. Summary of Thermal-Conductivity Test Results, Upper Portion of USW-G1*

Sample Number Grain(equivalent to Density Thermal Conductivity (W/m'C) at Temperature ('C)depth in feet) (g/cm3 ) Porosity 23 100 165 212 260

795.01330.01503.01706.02010.02070.02274.42310.02311.02367.9A2472.32473.12474.02493.OB2536.02568.02569.02701.02814.02928.32938.83050.0

2.522.382.482.332.402.412.362.442.412.592.622.622.622.622.652.412.442.422.632.652.642.59

0.110.030.380.330.280.290.340.370.360.250.320.290.310.270.220.300.320.310.240.190.180.26

2.151.181.301.171.281.331.371.381.381.881.881.791.721.881.901.351.371.392.262.072.101.95

2.151.241.341.211.381.431.411.431.441.841.841.741.701.901.851.411.421.442.242.022.091.98

2.051.281.281.241.421.471.421.431.441.791.851.761.691.931.841.471.441.452.122.012.081.98

1.280.97

0.971.091.801.011.121.141.051.061.151.341.061.191.20

1.551.57

1.331.02

0.920.91

1.050.961.091.151.031.041.171.311.031.151.021.401.521.561.53

*Tests at elevated temperature conducted at Pc = 10 MPa, Pf = 1.5 MPa. Tests at ambient temperature include both confinedand unconfined results. Conductivities listed are average values for each sample at specified condition.

10

Topopah Spring Member,Paintbrush Tuff

The Topopah Spring Member of the PaintbrushTuff extends between depths of 71.6 and 434.4 m (235and 1425 ft) in Hole GI (Table 1). The bulk of thisunit, described regionally by Lipman, Christiansen,and QlConnor,4 .,is_ deisely weloed and devitrified,consisting of a mix of alkali feldspar, cristobalite, andquartz.'456 Bulk-property measurements on this unitin Hole Gi (listed in Table D-1) indicate that matrixporosity in the central welded, devitrified zone is 0.10to 0.12. In this study, thermal conductivity of denselywelded, devitrified Topopah was measured on Sample795 from 795 ft (242.3 m) depth. Throughout thereport, sample numbers correspond to depth in feet,since all records of drilling and coring operations arekept in English units. The margins of the TopopahSprings consist of densely welded to nonwelded vitrictuffs. Sample 1330 is from the densely welded basalvitrophyre.

One complication in interpretation and applica-tion of material-property and thermal-conductivitydata from the densely welded, devitrified TopopahSprings is the widespread occurrence of lithophysae inthe unit. These features, originally gas-filled voids, arenow lined or filled with high- and/or low-temperatureminerals, and occur in locally varying concentrationsthroughout most of the devitrified zone. The thermalconductivity of Sample 795, which is free of lithophy-sae, thus cannot be applied directly to lithophysalzones.

The results of thermal-conductivity measure-ments on Samples 795 and 1330 are summarized inTable 3, and listed in detail in Table C-1. Thefully saturated conductivity of Sample 795 (pg =2,52 g/cm 3, 4k = 0.11) is near 2.15 W/mWC to a tem-perature near 100'C independent of pressure, butdecreases slightly with increasing temperature, to2.05 W/mWC (corrected, see Appendix B) at about165°C. Measurements after dehydration, whichoccurs near 200°C under the confined conditions, werenot successful. The confined saturated conductivity ofSample 1330 (pg = 2.38 g/cm3, 4 = 0.03) increasesfrom 1.18 W/m°C at ambient temperature to1.28 W/m°C at 165°C. Dehydration has littleeffect, with conductivity reaching a maximum of1.33 W/m 0C at 280 0C.

Saturated results on Sample 795 are in excellentagreement with previous measurements on samplesfrom the devitrified portion of this unit. Measure-ments on a sample from a depth of 379.5 m (1245 ft) inHole Gi indicate a fully saturated conductivity of2.17 W/m0 C.7 A sample from a similar portion of this

unit in Hole UE25A#1, at a depth of 481.9 m (1253 ft),has a saturated conductivity of 2.08 W/m°C.8

Few reliable data exist on the dehydrated thermalconductivity of this type of tuff. The reported dehy-drated conductivity of Sample 1245 (unconfined) is1.87 ± 0.04 W/m°C at temperatures between ambientand 100°C, after dehydration at near-ambient tern-

-',.peratures.7 In the case of Sample UE25A#1 I- 1253:,measurements at ambient temperature after samp)ledehydration indicate a conductivity of 1.85 WX/i'Cthis decreases to 1.57 W/m°C at 100"C(' ad1.40 W/m°C at 3000C. Measured conductivities olndehydrated material from the nonlithophysal, denselwelded, devitrified Topopah Springs thus range from1.85 to 1.60 W/m°C at 100°C.

A gradual increase in conductivity with increasingtemperature is characteristic of many glasses. Consistent with this, Sample 1330 is from a zone tlhTis almost entirely glassy. 4 6 In fact, the confined conductivity of 1330 after dehydration is "identicaf" tothat reported in the literature for obsidian (I.28i.1.42 W/m°C), fused silica (1.33 to 1.36 W/m°('), an(lbasaltic glasses (1.37 W/m°C).9 The porosity of Sarnple 1330 (4 = 0.03) is so low that the increase in glassconductivity with increasing temperature more thanmakes up for any decrease in total conductivity resu lIing from dehydration near 200°C.

Tuffaceous Beds of Calico Hills(Informal)

The Tuffaceous Beds of Calico Hills ext end I rwy434.4 m (1425 ft) to 549.3 m (1802 ft) in Hole ( l. TI,unit is variable, and contains both nonwelded ashflows and bedded or reworked tuffs. Individual aslflows in the unit are nonwelded, and, as shown iWTable D-2, generally characterized by high porositiv(>30( ) and grain densities of <2.5 g/cm3. The ImNgrain densities reflect extensive formation of zeolitc-especially clinoptilolite.6 The zone of zeolitization e-tends both upward into the lower portion of theTopopah Springs and downward into the underlyin_Prow Pass Member of the Crater Flat Tuff.

Thermal conductivity of two samples of nonwelded ashflow from the Tuffaceous Beds of Calico Hillswas measured in this study: Samples 1503 and 17)06.Results are summarized in Table 3; detailed values aregiven in Table C-2. In both cases, the saturated ther-mal conductivity is relatively constant from ambienttemperature to 165°C (confined). The conductivity ofSample 1706 (pg = 2.33 g/cm3 , 4 = 0.33) increase.slightly from 1.17 to 1.24 W/m°C before dehydration:that of Sample 1503 (pg = 2.48 g/cm 3 , 4 = 0.38) is lesstemperature-dependent, remaining near 1.30 NV/ni(".

I I

The saturated conductivities from the TuffaceousBeds of Calico Hills reported here are in good agree-ment with results obtained previously. Reported am-bient-pressure conductivities from the unit in HoleUE25A#1 are 1.26 W/mrC at 478.2 m (1569 ft),7 and1.10 W/m0C at 474.0 m (1555 ft).'0 It thus appearsthat the saturated thermal conductivity of the ashflowportions of the Tutfiieous Beds of aidioffllsrangesonly from' about 1.1 to 1.35 W/m 0C in HolesUE25A#1 and Gi.

Measurements of dehydrated conductivity ofSample 1706 were not successful. A portion of themeasurements on Sample 1503 in the dehydratedstate were successful and indicate a conductivity near1.0 W/m0C. This compares with previously reportedvalues from Hole UE25A#1, 0.75 W/m0 C at- both474.0 and 478.2 m (1555 and 1569 ft).

Prow Pass Member of the CraterFlat Tuff

The Prow Pass is the uppermost member of theCrater Flat Tuff," extending between depths of 549.3and 662.3 m (1802 and 2173 ft) in Hole GI, andbetween 559.6 and 711.1 m (1836 and 2333 ft) in HoleUE25A#1. The static water level, at 564-m depth, is inthe upper Prow Pass in Hole GI. In this hole, the unitcontains partially to moderately welded ashflow tuffs,with a thin zone of bedded/reworked tuffs at the base.Bulk-property measurements in Table D-3 indicatethat porosity in the unit as a whole ranges from about0.22 to 0.37. Grain densities, except for Samples 1886through 1973.7, all are <2.5 g/cm3, indicating that thebulk of the unit is zeolitized, consistent with mineral-ogical results.6

Thermal conductivity of two samples from theProw Pass has been measured in this study: Samples2010 and 2070. Both samples come from a partiallywelded, zeolitized zone. Detailed conductivity resultsare given in Table C-3. The apparent thermal conduc-tivity of Sample 2010 (p5 = 2.40 g/cm3, 4 = 0.28) isstrongly sensitive to confining and/or fluid pressure.This response is probably caused by collapse of thesample on loading, which removed a contact resis-tance present at ambient pressure. The ambient-pressure data are suspect. Thermal conductivity un-der pressure, as shown in Table 3, increases from 1.28to 1.42 W/m0 C between ambient temperature and1650C, and apparently decreases only slightly upondehydration.

Given previous results,9 the slight decrease ondehydration appears unlikely in a material of thisporosity. The sample probably failed to dehydrate in

the time initially allowed; only the conductivity mea-sured at 280'C, 0.92 W/m0C, is assumed representa-tive of the dried material.

These interpretations are supportd by results onSample 2070. The saturated conductivity of this sam-ple (p5 = 2.41 g/cm3, 4 = 0.29) increases from 1.33 to

-1.47 W/mR°C -between ambient temperature and-165,V; is indepeidentdof confining pressure, and de-

creases in a single step to 1.0 W/m0 C upon dehydra-tion near 200'C. Conductivity decreases slightly withincreasing temperature above 212'C.

Samples of the Prow Pass from Hole UE25A4*1are quite different from those analyzed here. Samplesat depths of 594.1, 599.2, and 609.6 m (1949, 1966, and2000 ft) have been tested.7 8 10 Grain densities andporosities of these three samples are 2.63 gm/cm3, 0.18(Sample 1949); 2.62 gm/cm3, 0.19 (Sample 1966); and2.56 gm/cm 3, 0.15 (Sample 2000). Thus, the sampleshave both higher grain density and lower porositythan those analyzed here. Reported saturated thermalconductivities of the three samples from HoleUE25A#1 are 1.76, 1.49, and 1.43 W/m1C respective-ly; dehydrated values 1.35, 1.12, and 1.23 W/m0C.There is thus surprisingly little difference between thereported conductivities from the Prow Pass in HoleGi, measured on samples that are zeolite-bearing andhave porosities near 0.3, and those of samples fromHole UE25A#1 that have porosities near 0.2 andhigher grain densities. The thermal conductivity ofthe Prow Pass remains poorly understood.

Bullfrog Member of the Crater FlatTuff

The Bullfrog is the second highest member of theCrater Flat Tuff, extending between depths of 662.3and 804.4 m (2173 and 2639 ft) in Hole Gi. Within theunit as a whole there is broad variation in bulk andgrain density, as well as porosity (Table D-4). Thenonzeolitized, partially-to-densely-welded portion ofthe unit extends between depths Qf -713.2 and776.3 m (-2340 and 2547 ft). The lower portion of thisinterval is the most densely welded (O -0.2), and isseparated from less welded tuffs below by a sharpinterface. The upper boundary of the nonzeolitizedzone is somewhat arbitrary.

Mineralogical alyses6 are consistent with thissubdivision of the Bullfrog. Clinoptilolite and mor-denite are abundant in the upper portion of the unit,but are absent in a sample from a depth of 706.5 m(2318 ft). Zeolites are then totally absent with increas-ing depth until some point between samples collectedat depths of 757.7 m (2486 ft), in which they are

12

lacking, and 778.8 in (2555 ft), in which they make up40% to 90% of the sample. Zeolites are abundantbelow this depth.

For purposes of evaluating thermal conductivityof the Bullfrog, samples are broken into two groups inthis study. The first group, within which conductivityhas been measured successfully on six samples, con-tains. samples from between 713.2 and 776.3' m (2340and 2547. ft); P rosities range fromF 0.20 t 0.30 andgrain densities from 2.55 to 2.66 g/cm3 (see Table D-4).The second group, in which five conductivities havebeen measured, contains zeolitic tuffs both above andbelow the zeolite-free zone. Porosities in this grouprange from 0.25 to 0.40, and grain densities from-2.31 to 2.58 g/cm3.

Conductivity results for the group of samplesfrom the central nonzeolitized portion of the unit aregiven in Table C-4 and summarized in Table 4, alongwith selected bulk properties of the tested samples.Conductivity is relatively uniform, with the standarddeviation of all measurements being 0.1 W/m0C or

less at all test conditions. Fully saturated conductiv-ities of 1.7 to 1.9 W/m 0C decrease to 1.05 to1.15 W/m0 C after dehydration near 2001C. The onlyexception is Sample 2536 which, consistent with itshaving the lowest porosity of samples tested, showsthe smallest decrease in thermal conductivity as aresult of dehydration, from 1.84 to 1.34 W/mrC.

Test results for the zeolitized tuffs above andbelow the central portion of the Bullfrog are given inTable C-5 and summarized in Table 5. The averagesaturated conductivity of these tuffs varies between1.35 and 1.45 W/m0C, increasing slightly with increas-ing temperature. Conductivity decreases to 1.0 to1.2 W/m0 C upon dehydration.

Measured conductivities of nonzeolitized weldedBullfrog from Hole UE25A#1 are summarized inTable 6. In general, both saturated and dehydratedconductivities of tuffs from A#1 are greater than ofmaterial from G1. This difference appears to be real,and to correlate with lower average porosity.

Table 4. Summary of Thermal-Conductivity Test Results, Central Nonzeolitized Portion ofBullfrog Member, Crater Flat Tuff

GrainDensity Thermal Conductivity (W/m°C) at Temperature (°C)

Sample (g/cm3) Porosity 23 100 165 212-215 260-280

2367.9A 2.59 0.25 1.88 1.84 1.79 1.12 1.092472.3 2.62 0.32 1.88 1.84 1.85 1.14 1.052473.1 2.62 0.29 1.79 1.74 1.76 1.05 1.032474.0 2.62 0.31 1.72 1.70 1.69 1.06 1.042493.OB 2.62 0.27 1.88 1.90 1.93 1.15 1.172536.0 2.65 0.22 1.90 1.85 1.84 1.34 1.31Average (all) 2.62 0.28 1.84 1.81 1.81 1.14 1.131 Standard 0.02 0.02 0.07 0.08 0.08 0.10 0.10Deviation

13

Table 5. Summary of Thermal-Conductivity Test Results, Zeolitized Portion of BullfrogMember, Crater Flat Tuff

GrainDensity Thermal Conductivity (W/m0 C) at Temperature (0 C)

Sample (g/cm3) Porosity 23 100 165 212-215 2602274.4 2.36 0.34 1.37 1.41 1.42 1.09 -2310.0 2.44 0.37 1.38 1.43 1.43 1.08 1.052311.0 2.41 0.36 1.38 1.44 1.44 1.01 0.962568.0 2.41 0.30 1.35 1.41 1.47 1.06 1.032569.0 2.44 0.32 1.37 1.42 1.44 1.19 1.15Average (all) 2.41 0.34 1.37 1.42 1.44 1.09 1.05I Standard 0.03 0.03 0.01 0.01 0.02 0.07 0.08Deviation

Table 6. Thermal-Conductivity Test Results, BullfrogMember, Crater Flat Tuff, Hole UE25A#1 (Data from Refs 7and 9)

Grain Approximate ThermalDensity Conductivity (W/m'C)

Sample Porosity (g/cm3) Saturated Dry

2341.0 0.26 2.70 - 1.742365.0 0.24 2.66 2.40 -2389.0 0.25 2.61 1.47 1.062429.0 0.15 2.63 1.76 1.342432.0 0.18 2.64 2.19 1.362448.0 0.24 2.68 2.65 -2499.0 0.20 2.63 1.90 1.23Average (all) 0.22 2.65 2.06 1.351 Standard 0.04 0.03 0.43 0.25Deviation

Tram Member of the CraterFlat Tuff (Informal)

The Tram is the lowermost member of the CraterFlat. While the distributions of the Prow Pass andBullfrog Members are fairly well known, very little isknow about the Tram because its outcrop is limited.The member extends between depths of 804.4 and1084.5 m (2639 and 3558 ft) in Hole G1. Mineralogicalstudies6 indicate that, except for a zone extendingfrom -845.8 to between 914.4 and 929.7 m (-2775 tobetween 3000 and 3050 ft), the unit is zeolitized. Incontrast to shallower zones, analcime is an importantzeolite, occurring, instead of mordenite, with clinopti-lolite.

Thermal conductivity has been measured on sixsamples from the Tram. Sample 2701, from the upperportion of the unit, is zeolitized. Samples 2814, 2842,2928, and 2939 are from the portion free of zeolites.Sample 3050, though slightly lower in grain densitythan the samples above it, is considered to be withinthe nonzeolitized portion of the unit.

Test results for the nonzeolitized portion of theunit are given in Table C-6 and summarized inTable 7. Bulk properties for the unit are given inTable D-5. The conductivity of samples from thenonzeolitized portion is fairly uniform at between 2.0and 2.25 W/m0 C before dehydration, generally de-creasing slightly with increasing temperature. Theconductivity in this zone after dehydration appears to

14

be near 1.5 W/m 0C. The zeolitized Sample (2701)from the upper portion of the Tram is similar in bothconductivity and material properties to zeolitizedtuffs from the Bullfrog (see Table 3).

A check of the accuracy of measurements made aspart of this study is provided by data shown inTable 8. Samples at two depths within the nonzeoli-tized part of the Tram were split, one half-analyzed atTerra Tek, the second half at the US GeologicalSurvey laboratories in Menlo Park, California. The

USGS samples were analyzed in the as-received stateof saturation. As shown, there is excellent agreementbetween results at a depth near 892.5 m (2928 ft). Thedifference between the reported conductivities is only±3 % of the average value. At a depth of 895.8 m(2939 ft), the relative difference is somewhat greater,about ± 8% of the average. These measurements arethus consistent with the conclusion that conductiv-ities reported here should, conservatively, be preciseto ± 10%.

Table 7. Summary of Reliable Thermal-Conductivity Test Results, Nonzeolltized Portion ofTram Member, Crater Flat Tuff

GrainDensity Thermal Conductivity (W/m 0 C) at Temperature (0 C)

Sample (g/cm3) Porosity 23 100 165 -212 245-280

2814.0 2.63 0.24 2.26 2.24 2.12 - 1.402928.3 2.65 0.19 2.07 2.02 2.01 1.55 1.522938.8 2.64 0.18 2.10 2.09 2.08 1.57 1.563050.0 2.59 0.26 1.95 1.98 1.98 - 1.53Average (all) 2.63 0.22 2.10 2.08 2.05 1.56 1.501 Standard 0.03 0.03 0.13 0.11 0.06 - 0.07Deviation

Table 8. USGS - Terra Tek Thermal-Conductivity Comparison TestResults*

Grain SaturatedSample Density Conductivity Arelative**

Depth (ft(m)) Porosity (g/cm3 ) (W/mOC) (W/mOC)

2928.1 (892.5)(Terra Tek)

2929.1 (892.8)(USGS)

2938.8 (895.8)(Terra Tek)

2939.3 (895.9)(USGS)

0.19 2.65 2.03 + 0.06

0.15t

0.18

0.16t

2.65

2.64

2.64

1 .880)1.94(2)

2.08

1.81(l)1.87(2)

- 0.09- 0.03

+ 0.12

- 0.15- 0.09

*USGS data contained in personal communication by J. Sass, USGS, to A. R. Lappin, Sandia,dtd March 9, 1981.**Calculated relative to the average of the Terra Tek determination and average USGSdetermination.tUSGS determination. All other bulk-property data from Terra Tek."Conductivity determined on disk by guarded-end-plate technique.MConductivity determined by back calculation from experimental measurement in water-filledchamber containing rubbled sample. Technique described in Ref 13.

15

Thermal StratigraphyTwo factors inhibit lateral and vertical correlation

of tuff thermal conductivities. First, ashflow units areinherently variable in vertical profile, especially asregards porosity. Second, as a response to variations inpermeability, initial temperature, and geologic set-ting, tuff mineralogy varies. Any attempt at a general-ized understanding of the thermal conductivity oftuffs must take both factors into account.

Correction for the effects of porosity is relativelystraightforward under some conditions. Several meth-ods have been proposed and used to back-calculate to"zero-porosity" or matrix thermal conductivity (K.)from laboratory measurements (for example, Refs 12,13, and 14). The method used here is an extension ofthat used by Woodside and Messmer.14 In this empiri-cal method,9 the measured thermal conductivity,Km"", is assumed to be

Kme r K(e - ) KO(I-.) KO(

where

KmesKrock = measured rock conductivityK( = theoretical matrix conductivity at zero

porosityq5 = porosityKg = conductivity of airs = relative saturation of sampleKw = conductivity of liquid water. All conductiv-

ities are in units of W/m0 C, and both porosi-ty and saturation are in decimal notationrather than percent.

By means of simple rearrangement, calculated Kovalues can be obtained from

K. (Kmeakg )( 1 2K0 = (KKg U - 8 ) K (2)

Calculated K0 values for the samples analyzedhere are given in Table 9. Because of uncertaintiesregarding the effective thermal conductivity of air inthese samples and lack of success in previous attemptsto measure conductivity of partially saturated materi-al, the K0 values given are based on measurements atcomplete saturation (s = 1.0), assuming a liquid waterconductivity of 0.605 W/m°C.'5 The geometric-meansapproach, though empirical, yields excellent agree-ment with other methods in calculating the matrixconductivity of basalts."3

Once the calculated value of the matrix thermalconductivity has been determined from measure-ments on fully saturated material, the conductivity ofair can be calculated from measurements on fullydewatered samples. Calculated air conductivities areincluded in Table 9. As shown, the values fall into twodistinct groups. For devitrified samples (grain density22.5 g/cm3), the apparent air conductivities rangefrom 0.08 to 0.24 W/m0 C, and average 0.12± 0.05 W/m0C. Effective air conductivities in the zeolitizedtuffs range from 0.18 to 0.37 W/m0 C and average0.27 ± 0.06 W/m0C. The apparent conductivity of airin Sample 1330 is 19.66 W/m0C. These values com-pare with 0.03 to 0.04 W/m0C for air and steam in thesame temperature and pressure range as measure-ments were made here.16

The difference between apparent and textbookvalues may be due to several causes. First, it is as-sumed here that the matrix conductivity is indepen-dent of temperature. This is almost certainly not thecase.9 In the case of devitrified tuffs, while the conduc-tivity of feldspars may increase slightly with increas-ing temperature, that of quartz is well documented todecrease. Many of the samples of devitrified tuffanalyzed here show a slight decrease in saturatd con-ductivity with increasing temperature. There is nomajor phase in these tuffs that should show an in-crease in conductivity due to dehydration, since noneof the main silicate phases are dehydrated at thetemperatures of interest.

A relatively high apparent thermal conductivityof air is common, however, in other studies on rockscontaining primarily anhydrous phases (see, for exam-ple Ref 13), and may be due to the formalisms used, toreported porosities being slightly too high, or to heattransfer processes being active that are not included inthe calculations. In the case of vesicular basalts, theapparent air thermal conductivity in dehydrated sam-ples is 0.14 W/m0C,13 quite close to that calculatedhere for devitrified tuffs, 0.12 W/m0 C. Due to itsapparent validity for both basalts and devitrifiedtuffs, this number is considered reliable.

As shown in Table 9 however, the average appar-ent thermal conductivity of air in dehydrated samplesof zeolitized tuffs (grain density <2.5 g/cm3) is greaterthan that in devitrified samples, 0.27 ± 0.06 W/m 0C,vs 0.12±0.05 W/m0C. Even accepting the high airconductivity in devitrified tuffs and basalts, theremust be one or more additional mechanisms operatingin the zeolitized samples. One factor is probably thefact that, contrary to assumptions made here, thematrix conductivity of zeolitized (and vitric) materials

16

actually increases with increasing temperature, espe-cially if dehydration occurs. The effect is most strikingin Sample 1330. In this case, due to the low porosity(O = 0.03), the increase in glass conductivity withincreasing temperature and dehydration more thanmakes up for the effects of dewatering, with the resultthat overall sample conductivity is actually highestafteivit yd atiqn. The apparent air therwnal penduc-tivity afterdehydration of -this sample, assuming the

matrix conductivity to be temperature independent at1.20 W/m0C, is 19.66 W/m0 C. If, however, it is as-sumed that dehydration increases the matrix conduc-tivity of the glass in Sample 1330 to near that ofanhydrous glass, say 1.4 W/m0 C, then the apparentair thermal conductivity is reduced to 0.14 W/m0C,consistent with results on devitrified tuffs,

. i,''; .1..... i''q1 ~..;. : ................ ,,.,., ;

Table 9. Calculated Matrix Conductivity (K0) and Air Thermal-Conductivity (Kg) in Analyzed Samples

Sample Number Grain(equivalent to Densitydepth in feet) (g/cm3) Porosity K0(W/m0 C)(') K5 (W/m0C)(2)

795.01330.01503.01706.02010.02070.02274.42310.02311.02367.9A2472.32473.12474.02493.0B2536.02568.02569.02701.02814.02928.32938.83050.0

2.522.382.482.332.402.412.362.442.412.592.622.622.622.622.652.412.442.422.632.652.642.59

0.110.030.380.330.280.290.340.370.360.250.320.290.310.270.220.300.320.310.240.190.180.26

2.511.202.081.621.711.832.092.242.192.743.212.792.752.862.621.902.012.023.432.762.762.94

19.660.30

0.190.180.310.300.240.070.130.090.120.100.120.260.370.290.080.130.120.24

/ ~~~~~~~~I(')Ko = R ... ,)) -~ , where Kme,, is measured in the fully saturated state, and Kwa,,, taken to

be 0.605 W/m0C (Ref 15)

-,. , in' " ) , where Kme. is measured in the dehydrated state, and K. is calculated as de-

fined above.

's.

17

A similar argument can be made with partialsuccess in the case of zeolitized tuffs. Conductivities ofdehydrated zeolites (in addition to opal and expand-able clays) are unknown. Several of the zeolitizedsamples analyzed here show a slight increase in ther-mal conductivity in the saturated state with increas-ing temperature. The average matrix conductivity ofthese tuffs in the saturated state is 1.97 W/m0 C. If it isassumed that the effective thermal conductivity of airin the dewatered samples is 0.12 W/m0C, then, at theaverage porosity of 0.33, a dehydrated thermal con-ductivity of 1.04 W/m0C requires a matrix conductiv-ity of 3.01 W/m0C, as opposed to the assumed value of1.97 W/m0C. This appears unlikely. Another possibil-ity, since water is released from such hydrous phasesas zeolites over a range of temperatures, is that thetransient heating of a portion of these tuffs duringconductivity measurement in the "dehydrated" condi-tion results in vaporization of additional crystal-bound water near the heating probe. Such a processwould be endothermic, and result in too high anapparent thermal conductivity.

The prediction of thermal conductivity of dehy-drated, zeolitized tuffs is thus somewhat unsatisfac-tory using the geometric-means approach, since itrequires use of an effective air conductivity of0.27 W/m0C, an order of magnitude greater than thetextbook value. However, so long as the porosity rangeto which estimated conductivities are extrapolated issimilar to that from which the zero-porosity conduc-tivities were calculated, the results should be reliable.In the case of zeolitized tuffs, results would appearreliable for tuffs having porosities between -0.25 and0.40.

Variations in zero-porosity or matrix conductivityas a function of mineralogy can, to a first approxima-tion, be understood as a function of grain density.This is helpful in extrapolation of conductivities toregions where mineralogical data are not available.Lappin9 developed a theoretical curve of K. vs graindensity, and related this curve to both mineralogy andearly experimental results. The theoretical curve, re-sults reported here, and some earlier experimentalresults are shown in Figure 2.

In Figure 2, Curve A represents approximatechanges ingrain density and matrix conductivity re-sulting from zeolite formation at the expense of pri-mary anhydrous glass having a deinsity of 2.41 g/cm3

and conductivity of 1.35 W/m°C.9 There is little ap-parent change in thermal conductivity because ofzeolitization, though conductivity data for zeolites aresparse; none are available for clinoptilolite. Hydrationof initially anhydrous glass (as in the case of Sample1330) decreases its conductivity and grain density

below values shown in the figure. Curve B representschanges in both thermal conductivity and grain densi-ty as anhydrous glass devitrifies to a mix of cristoba-lite and alkali feldspar, assuming a 30:60 ratio ofcristobalite/feldspar. Curve C represents changes indensity and conductivity with varying cristobalite/feldspar ratios, assuming complete devitrification.Curve D represents variations in matrix conductivityand density in quartz-bearing tuffs, assuming com-plete inversion of cristobalite. Assuming that pheno-crysts and secondary phases such as montmorilloniticclays are negligible, the curves in Figure 2 shouldprovide an estimate of minimum zero-porosity ther-mal conductivity as a function of both grain densityand mineralogy.

The relationship between grain density and min-eralogy provides a method for dividing most tuffs intothree distinct groups. Tuffs with a grain density< -2.5 g/cm3 should either be vitric or should haveundergone some zeolitization (Trend A) and/or devit-rification to feldspar and cristobalite (Trend B). Tuffsthat have undergone a combination of zeolitizationand devitrification should have a zero-porosity con-ductivity lying above the A and B lines, in field E.Tuffs with a grain density between 2.5 and 2.58 g/cm3

should be simply devitrified, consisting largely ofcristobalite and feldspars. Tuffs with a grain densityof > 2.58 g/cm3 should be largely a mixture of quartzand alkali feldspars.

Mineralogical studies to date,5 6 generally supportthis subdivision. Eight of the 10 zeolitized tuffs stud-ied here come from zones in which the combined totalof zeolite, cristobalite, and feldspars is >90% of therock. Clay contents are low and quartz contents<10% .6 In most cases, the estimated content of cris-tobalite is also quite low, so that the tuffs may bethought of as a mix of zeolite and feldspar. Theaverage calculated zero-porosity conductivity of the10 zeolitized tuffs studied here is 1.97±0.20 W/m°C,represented by value 1 in Figure 2. Average graindensity is 2.41 + 0.04 g/cm3. Zero-porosity conductiv-ity of these tuffs is thus statistically uniform withinexperimental error, independent of depth and strati-graphic unit.

Results for the six sets of data on the nonzeoli-tized portion of the Bullfrog are also quite uniform, asindicated by point 2 in Figure 2. The reported miner-alogy in this portion of the unit consists of >95%total quartz, feldspars, and cristobalite (or opal). 6 Theaverage zero-porosity conductivity of the nonzeoli-tized Bullfrog is 2.83 ± 0.20 W/m°C in Hole G1 (point2, Figure 2), compared to 2.91±0.89 W/m°C in HoleA#1 (point 3). Average grain densities are 2.62 ± 0.03and 2.65 ± 0.03 g/cm 3, respectively. Thus, although the

18

measured saturated conductivities are somewhatdifferent, there is no statistically significant differencebetween the average zero-porosity thermal conductiv-ities of the nonzeolitized Bullfrog in the twoholes. Zero-porosity conductivity (2.97 ± 0.32 W/m0 C;

point 4, Figure 2) and average grain density(2.63 ± 0.03 g/cm3) of nonzeolitized samples from theTram are almost identical to corresponding values forthe Bullfrog in both Hole Gi and Hole A#1.

-'

_ '

0

0n

'a

r_

0

L._

so

0._

N

4.0

3.0

2.0

- - I . , . . . , j~~~I

to Quartz'1to Cristobalite 3

3

tA ! Feldspars 4,

. I,,~~~~~~~~~~~~~

to Zeolites *A-~ ~ , Glass

1.02.2 2.3 2.4 2.5 2.6 2.7

3Grain Density (g/cm )

Legend

Unit Hole Symbols Unit Hole Symbols

Topopah Springs Member, Gl V All Zeolitized Tuffs Gi 1Paintbrush Tuff Al v (Average K., pg)

Tuffaceous Beds of Gl * Nonzeolitized Bullfrog Gl 2Calico Hills Al C (Average K,,, pg) Al 3

Prow Pass Member, GI Nonzeolitized Tram Gl 4Crater Flatt Tuff Al (Average Ko, pg)

Bulldog Member, GI Densely Welded, Gl 5Crater Flat Tuff Al 0 Devitrified Topopah Al

Tram Member, Gi A Springs (Average K 0, pg)Crater Flat Tuff

Figure 2. Theoretical Grain Density-Conductivity Relationship and Calculated K0 Values for Silicic Tuffs From UE25A#1and USW-G1

19

The zero-porosity conductivity of all nonzeoli-tized Bullfrog and Tram samples analyzed to dateaverages 2.89 ± 0.53 W/m0 C. The average zero-porosity conductivities of the three data sets are 2.83,2.91, and 2.97 W/m0C. Average zero-porosity conduc-tivities of these nonzeolitized devitrified tuffs thusappear to be statistically uniform, independent ofdepth, stratigraphic unit, and location. There may besome statistically significant variation within thewelded Bullfrog in Hole A#1.

It should be noted that zero-porosity conductiv-ities calculated here for devitrified, welded Bullfrogand Tram, while internally consistent, are lower thanexpected solely on the basis of simplified mineralogy.Reported quartz/feldspar ratios in devitrified Tramand Bullfrog analyzed to date range from -30/60 to50/40. Ignoring the presence of all other minerals, thisshould lead to zero-porosity conductivities between3.5 and 4.2 W/m0C, as compared to the average calcu-lated value of 2.9 W/m1C. The difference may be dueto either invalidity of some of the assumptions inher-ent in the geometric-means formalism or to effects ofsmall amounts of such phases as expandable clays, notconsidered here. Nonetheless, use of the approachdescribed here yields internally consistent results,applicable over a porosity interval similar to that ofthe samples from which calculated zero-porosity conductivities have been derived. On thebasis of the samples analyzed here, the range of reli-able application appears to extend between 0.2 and 0.4porosity.

Data for evaluation of the densely welded, devitri-fied Topopah Springs are limited. Three measure-ments of saturated conductivity in this zonelead to a calculated zero-porosity conductivityof 2.44 ± 0.08 W/m0 C, shown as Point 5 in Figure2. Average grain density of these samples is2.55 ± 0.03 g/cm3. Note that, though Samples 795 and1245 both come from zones in which there .has beenonly limited inversion of cristobalite to quartz, abun-dant quartz does occur locally within devitrified por-tions of the Topopah Springs.86 Although the data areextremely limited, it is tentatively concluded thatzero-porosity conductivity of cristobalite-bearing de-vitrified welded tuffs with grain densities between-2.5 and 2.58 g/cm3 is also statistically uniform,indpendent of location.

When combined with the bulk-property measure-ments given in Appendix D, the conductivity resultspresented here provide a basis for developing a satu-rated thermal-conductivity stratigraphy for intactmaterials in the upper portion of Hole GI. In all unitsbut the Topopah Springs, it is assumed that reportedvalues are representative of the units sampled in the

absence of fractures. In the case of the TopopahSprings, correction must be made for the occurrenceof lithophysal cavities and incomplete matrix satura-tion.

With the exception of zeolitized tuffs, estimationof the potential effects of in-situ joints is relativelystraightforward. Preliminary measurements indicatethat a linear thermal expansion coefficient of 10 x10-6CC-i is reasonable for devitrified tuffs both aboveand below the water table."7 Assuming this to be true,that the temperature at which a welded tuff is em-placed is no greater than 1000°C3, that all contractionduring cooling is taken up in the form of planar joints,and that there is no reduction in joint aperture due tooverburden or tectonic stresses, a maximum of - 1%of the initial material length should be taken up byfractures at ambient temperature. This would corre-spond to a fracture porosity of 3 vol %, and wouldalmost certainly be an overestimate in most cases.

In the simple case of heat flow perpendicular to aset or series of planar joints, the effective thermalconductivity of the jointed mass (K~ff) is given by therelation shown in Equation 3, where K; and Xi arerespectively taken as the conductivity and length frac-tion occupied by the intact material, and Kj and Xj thecorresponding values for the joints. In the cases forwelded tuff considered here, Kj is taken to be either0.605 or 0.12 W/m°C, depending upon whether thejoints are assumed to be water or air-filled. Xi and Xjare 0.99 and 0.01 in all cases, corresponding to 3%fracture porosity.

Keff = 1 XXi x+Ki Kj

(3)

The effects of estimated maximum fracture poros-ities on the in-situ thermal conductivity of devitrifiedwelded tuffs are shown in Table 10. In the case ofsaturated tuffs below the water table, the estimatedreduction in in-situ conductivity is will below 10%1o,and is considered negligible. If these tuiffs are assumedto be dehydrated, however, including the containedjoints, the effect is on the order of 10 %, but still quiteminor. Thus, it is concluded that effects of inherentthermally-induced jointing on the in-situ thermal con-ductivity of devitrified welded tuffs below the watertable are negligible.

This may not be the case in such welded tuffs asthe Topopah Springs, when situated above the watertable. In this setting, although the matrix may be nearfull saturation, virtually all joints may be assumed air-filled. Under this assumption, the ambient-temperature conductivity of nonlithophysal Topopah

20

may be reduced from 2.1 to 1.8 W/m0 C, about 15%. Asimilar but smaller reduction in conductivity of thedehydrated rock mass is also possible. It is thereforeconcluded that in the case of the Topopah Springs,which is the most densely welded tuff encountered at

* - Yucca Mountain, effects of natural in-situ jointing onrock-mass conductivity may need to be considered.

Potential effects of nontectonic fracturing on the,-sithermal conductivity of zeolitized or no el - -

ed tuffs appear negligible. Since they are often em-placed as either ash-fall tuffs at near-ambient tem-perature or as marginal envelopes to ashflow sheets,such tuffs may have undergone only very limitedcooling in place. Thermally-induced jointing shouldtherefore be negligible. In addition, zeolitization ofzeolitized welded tuffs may have greatly reduced anyinitial fracture porosity. It is thus concluded that thein-situ rock-mass thermal conductivity of heavily zeo-litized or nonwelded tuffs should be quite near that ofthe intact material.

This is likely not the case in dehydrated zeolitictuffs. Preliminary information indicates that zeoli-tized (or vitric) tuffs may contract up to 3 vol % ormore upon dehydration. If a 3% figure is assumedrepresentative, then the in-situ conductivity ofzeolitized tuffs in the dehydrated state, assuming

the effective conductivity of air in the joints tobe 0.12 W/m0C, might be reduced from the valueof 1.04 W/m0C measured on intact material to-0.97 W/m0C. This change is probably negligible.

Table 11 contains the estimated conductivitystratigraphy for intact material from Hole USW-G1below a depth of 409.1 m (1342 ft). Contacts betweenindividua) zones wde' chosen largely on the basis ofW.k--uiperty measurements and mineralogical stud-ies. When possible, however, a combination of labora-tory measurements and data'from the downhole den-sity log was used. Numbers of specimens analyzed forbulk properties in each zone, average grain densities,and average porosities are listed. The individual layersare relatively uniform internally, especially the non-zeolitized welded tuffs. Initial saturation of nonweld-ed zeolitized tuffs, even above the water table is near1.0. Estimated conductivities were calculated usingthe geometric-means formula (Equation 1), averageporosities for each zone, and zero-porosity conductiv-ities of 1.95 W/m0 C for the heavily zeolitized tuffs and2.90 W/m0C for the nonzeolitized welded tuffs. Theaverage of the experimental measurements generallyfalls within one standard deviation or less of thecalculated saturated conductivity for that zone.

Table 10. Estimated Maximum Effects of In-Situ Thermal Fracturing on Rock-MassThermal-Conductivity of Welded Devitrifled Tuffs (Excluding Lithophysal TopopahSprings)

Thermal Conductivityof Intact Material Calculated Rock-Mass

Rock Type (Setting) (W/mOC) Ceonductivityt') (W/m0 C) A(W/mOC( 2) A, (3)

Welded Devitrified Tram 2.10 (saturated) 2.05 (matrix and joints saturated) 0.05 2.4(below water table) 1.56 (dry) 1.39 (matrix and joints dry) 0.17 10.9Welded Devitrified Bullfrog 1.84 (saturated) 1.80 (matrix and joints saturated) 0.04 2.2(below water table) 1.14 (dry) 1.05 (matrix and joints dry) 0.09 7.9Welded Devitrified 2.10 (saturated) 1.80 (matrix saturated, joints dry) 0.30 14.3Topopah Springs 1.85 (dry) 1.62 (matrix and joints dry) 0.23 12.4(above water table)

V

M'Calculated from Kff = X___Xi symbols defined in text

Ki Kj. . -(2)Thermal conductivity of intact material - calculated rock-mass conductivity(3)(A(W/m 0C) divided by conductivity of intact material) x 100

21

Table 11. Estimated Thermal-Conductivity and Bulk-Property Stratigraphy (Saturated) ofUpper Portion of Hole USW-G1 Below 409.1 m (1342 ft)

DepthInterval(mWft))

Grain Density(g/cm3)

... N) -(2Y laM(

Saturated ThermalConductivity (W/meC)

Calculated(4) MeasuredK N K la

Fully DehydratedThermal Conductivity

(W/mDC)Calculated( 5) Measured

K N K. la

Porosity_N X laRock Type Unit

409.1-569.1 -Zeolitized, non to(1342-1867) partially welded

569.1-605.6 Nonzeolitized, partially(1867-1987) to moderately welded

605.6-713.2 Zeolitized, non to(1987-2340) partially welded

713.2-776.3 Nonzeolitized, partially(2340-2547) to densely welded

776.3-847.4 Zeolitized, non to(2547-2780) partially welded

16 2.40 0.09 -16 0.34 0.03 1.31 2 - 1.24 - - 1.00 1 1.00

5 2.57 0.04 5 0.31 0.04 1.78 - 1.08

28 2.43 0.07 28

24 2.61 0.02 26

19 2.43 0.06 19

0.33 0.04 1.33

0.26 0.03 1.87

0.28 0.03 1.41

5 1.35 0.04 1.02 5 1.00 0.07

6 1.84 0.07 1.27 6 1.14 0.10

3 1.37 0.02 1.12 3 1.11 0.06

847.4-920.5 Nonzeolitized, partially 14 2.63 0.03 13(2780-3020) to moderately welded

0.20 0.03 2.12 4 2.10 0.13 1.53 4 1.51 0.07

N = Number of samples analyzed

-X = Average of measurements on analyzed samples

3a - Standard deviation

(4K'C' - K',' - OKO; KO values defined in text

(5)Calculated values derived from Kd-.lh = K'" - 'K:; K. and Kg defined in text

Saturated conductivities listed in Table 11 shouldbe fairly reliable. There is general agreement betweenexperimental and calculated results, and no majorinternal structural complication in these units thatmight affect data interpretation. Assumption of com-plete initial saturation is reasonable, and changes inporosity occur over relatively short stratigraphic in-tervals, documented both by downhole logging andlaboratory measurements. Likewise, there is goodagreement between calculated and measured conduc-tivities in the dehydrated condition, using effective airconductivities of 0.12 W/m°C in the nonzeolitizedtuffs and 0.27 W/m°C in the zeolitized. The agree-ment between measured and calculated values indi-cates that the samples on which conductivity wasmeasured are representative of the depth zones con-taining them.

This is not the case at depths of < -411.5 m(1350 ft), since the major unit at these depths, theTopopah Springs Member of the Paintbrush Tuff, isinternally complex, and not fully saturated. As men-tioned above, the unit contains abundant lithophysal

cavities, which are usually partially gas-filled. There-fore, to predict the in-situ thermal conductivity of theTopopah Springs, even assuming complete matrixsaturation, an estimate must be made of the effect ofair-filled porosity on thermal conductivity.

The initial approach taken here is to assume thatthe matrix or intact material in lithophysal portions ofthe Topopah has a porosity of 0.10 and saturatedthermal conductivity of 2.1 W/m°C. Lithophysae arethen considered to have a thermal conductivity of0.12 W/m°C. The effective conductivity of the rockmass is calculated using the geometric means ap-proach, with the conductivity of the intact materialtaking the place of the zero-porosity conductivity inprevious calculations.

Estimated conductivity for the Topopah Springsas a function of depth is given in Table 12, withlithophysal void volumes estimated for Spengler, etal.' The approximate average conductivity perpendic-ular to layering for the densely welded, devitrifiedportion of the Topopah Springs is reduced from -2.1to -1.6 W/m°C by the presence of lithophysae in the

22

matrix-saturated state. Assuming 0.6 to be the matrixsaturation in this zone, the conductivity is reducedslightly, the conductivity of nonlithophysal materialto 2.00 W/mWC, and that of the unit as a whole(perpendicular to layering) to 1.5 W/m0C. Bracketedvalues listed in Table 12 assume total dehydration andaffective air conductivity of 0.12 W/in0C.

An additional area of uncertainty presently re-mains in estimation of thermal conductivity of thetuffs in Hole G1 above the water table. Sample 1330 isthe only sample analyzed to date that consists largelyof glass. In the depth intervals between 9.1 and 89.3 m(30 and 293 ft), as well as between 392.3 and 424.9 m

(1287 and 1394 ft), field description and mineralogicalstudies' 6 indicate that the tuffs are almost entirelyglassy. Bulk-property determinations in these inter-vals are few. One approach to estimating thermalconductivity is to assume that the zero-porosity ther-mal conductivity of all glassy tuffs is the same as thatof Sample 1330, 1.20 W/m0C. With this assumptionand the assumption that the average porosity in thetwo intervals is 0.30, estimated thermal conductivityin the saturated state is -1.0 W/m0C. If 0.6 satura-tion is assumed, this is reduced to 0.8 W/m0 C. Thesame range of conductivities is assumed here for near-surface alluvium.

Table 12. Estimated Thermal-Conductivity and Bulk-Property Stratigraphy (Matrix-Saturated) of Upper Portion of Hole USW-G1 Above 409.1 m (1342 ft)*

Estimated Porosity Thermalor Assumption About Conductivity

Depth Interval (m(ft)) Rock Type Lithophysae (W/moC)**0-89.3 Alluvium, Nonwelded Vitric,(0-293) Thin Densely Welded Vitric Porosity = 0.30 1.0(0.8) 10.6]

Densely Welded, Devitrified89.3-133.5 Vapor Phase Zone 0% Lith.(1) 2.1(2.0) [1.8](293-438)133.5-141.1 10% to 30% Lith.(1) 30% Lith. 0.9(0.85) [0.80](438-463)141.1-150.3 Densely Welded 0% Lith. 2.1(2.0) [1.8](463-493)150.3-217.3 20% to 30% Lith., 15% Lith. 1.4(1.3) [1.2](493-713) "Commonly Filled"217.3-248.4 Rare Lith., 5% to 15% Lith., 5 % Lith. 1.3(1.7) [1.61(713-815) Occasional Lith.248.4-294.8 5% to 20% Lith., 10% Lith. 1.6(1.5) [1.4](815-967) "Generally Filled"294.8-303.9 20% to 30 % Lith., 10 % Lith. 1.6(1.5) [1.4](967-997) "Filled"303.9-365.5 5% to 15% Lith., "1/2 Filled, 10 % Lith. 1.6(1.5) [1.4](997-1199) 1/2 Unfilled"365.5-392.3 'Occasional" Lith. 0 % Lith. 2.1(2.0) [1.8](1199-1287)392.3-409.1 Densely Welded to Nonwelded,(1287-1342) Vitric Porosity = 0.30 1.0(0.8) [0.6]

*Parenthetical values assume 0.6 matrix saturation; bracketed values assume 0.0 matrix saturation**Matrix porosity of densely welded, devitrified tuff assumed to be 0.10')Lith. = Lithophysae

23

Tables 11 and 12 thus provide an estimated ther-mal-conductivity stratigraphy in the matrix-saturated state for intact material from the upperportion of Hole GI, and for the partial-saturationstate of the densely welded Topopah Springs andvitric tuffs above and below it. The tables do notconsider possible effects of jointing on in-situ thermalconductivity, since these generally appear. to be negli-gible.

Conclusions andDiscussions

Test results presented here are consistent with theconclusion that it is possible to measure the thermalconductivity of most silicic tuffs to within ± 10% orbetter using the transient-line-source technique. Zero-porosity or matrix thermal conductivity of heavilyzeolitized tuffs appears statistically uniform near1.95 W/m0C, independent of depth, stratigraphic for-mation, and detailed mineralogy. Zero-porosity con-ductivity of nonzeolitized welded tuffs appears uni-form near 2.9 W/m0C, independent of formation,depth, and location. Combination of average zero-porosity conductivities and effective air conductivitiesof 0.12 W/m0C in devitrified tuffs and 0.27 W/m0 C inzeolitized tuffs with laboratory bulk-property mea-surements, downhole density logs, and results of min-eralogical studies allows development of a thermal-conductivity stratigraphy for intact portions of thesilicic tuffs in the upper portion of Hole IUSW-G1 asshown in Tables 11 and 12. Calculated conductivitiesshould be valid so long as they are for tuffs ranginggenerally from 0.2 to 0.4 in porosity. In the case ofsuch tuffs as the Topopah Springs, the range of valid-ity remains to be determined.

In the stratigraphy, individual zones, the bound-aries of which do not coincide with boundaries ofnamed stratigraphic units, are relatively uniform in-ternally. In most cases, the standard deviations in

porosity and grain density within a zone are no greaterthan between duplicate measurements on the samesample. Estimated conductivities of tuffs below thewater table are most reliable. Above the water table,the detailed in-situ state of saturation remains un-known, and the major unit encountered, the TopopahSprings Member of the Paintbrush Tuff, is internallycomplex due to abundant lithophysae. At present,laboratory data are not available on the thermal con-ductivity of lithophysal zones. With the exception ofthe Topopah Springs, the values in Tables 11 and 12should be within 10% of the in-situ thermal conduc-tivity, based on estimated effects of thermally inducedfracturing. The effect of such fracturing is greatest(-14%) in devitrified, nonlithophysal TopopahSprings above the water table.

Much obviously remains to be done. The thermal-conductivity data coverage is quite uneven; most ofthe emphasis to date has been placed on tuffs belowthe water table, especially the nonzeolitized portionsof the Bullfrog and Tram Members of the Crater FlatTuff. Below the water table, additional measurementsare needed in the welded zeolitized portions of thesection.

Above the water table, further characterization ofthe Topopah Springs is required, including measure-ments and confirmation of an adequate predictivemodel for the thermal conductivity in lithophysalzones. In addition, measurements must be madeacross the lower contact of the Topopah Springs, fromthe densely welded devitrified portion of the unit intothe nonwelded vitric tuffs at its base.

Lateral extrapolation of the results and formal-isms presented here involves uncertainties. As pres-ently developed, the linking of conductivity with min-eralogy is indirect. This is necessary in regions wheremineralogical data are unavailable, but risky in re-gions near contacts between zeolitized and nonzeoli-tized zones. Additional mineralogy is required, espe-cially at and near such contacts.

24

APPENDIX A

Test Procedures for Sample Preparationand Bulk-Property Measurements

Sample PreparationSamples were prepared from competent sections

of sealed core received from USW-G1. Water was usedas a cooling medium during all cutting and coringoperations.

Although theories exist to estimate thermal con-ductivity of partially saturated materials, successfulmeasurements on tuff have been made to date only onfully saturated or fully dehydrated samples. Speci-mens were rehydrated by a vacuum-submersion tech-nique in which the sample is placed in a container ofdeionized water and a vacuum drawn to the vaporpressure of water. This vacuum is sustained for 2 to3 h, at which time the sample is removed and weighed.The evacuation and weighing process is repeated untilno weight gain is observed between weighings.

As-received saturation in these tuffs is generally0.7 to 0.9, so the only pore spaces requiring rehydra-tion are presumably near surfaces dehydrated duringhandling and preparation. Thus, the connate water inthe center of the core has apparently not been dis-turbed. The application of pore pressure during test-ing further reduces the amount of gas-filled void spacein the core.

Bulk PropertiesBulk properties were measured by standard meth-

ods. Detailed procedures, summarized below, are onfile with Sandia National Laboratories Quality Assur-ance.

Bulk DensityBulk density is deterntined by weighing a speci-

men in water and measuring its volume by mercurydisplacement. No attempt was made here to preservethe initial state of saturation. The specimen is thenoven-dried at 110±50C to constant weight and re-weighed. The original weight divided by the volume

yields the initial bulk density. Dried weight divided byinitial volume yields dry density, assuming no changein sample volume during drying. These relations aresummarized:

orig. wt. . dry wt.Bulk Density = ri Dry Density =orig. vol. orig. vol.

Grain DensityThe dried specimen is crushed, pulverized to ap-

proximately 100 mesh size, and weighed. Grain vol-ume is measured by water immersion. Weights areaccurate to ± 0.1% and volumes to 1.0%. Grain densi-ty is found by dividing grain weight by grain volume.

Grain Density = grain wt.grain vol.

Initial Water ContentThe water content of the specimen is calculated

by subtracting the specimen's dry weight from theinitial weight and dividing the resultant by the initialweight.

Initial Water Content = orig. wt. - dry wt.orig. wt.

Total PorosityThe total porosity of the specimen is calculated

from the dry bulk density and grain density as follows:

Total Porosity = 1 - Dry DensityGrain Density

Note that the "total porosity" reported here isbased on grain densities measured after crushing ofthe material to minus 100 mesh. Micropores complete-ly contained in grains passing this mesh, i.e., less than

25

about 0.15 mm in diameter, might be occluded and notincluded in the porosity measurement, except as theydecrease apparent grain density if dewatered duringsample drying.

SaturationReported saturations are calculated from the rela-

tion:

Bulk Density at Total SaturationThis value is calculated from the relation:

Bulk Density at Total Saturation =(Grain Density x (1 - 0) + 0)

Saturation =Orig. Bulk Density - Dry Bulk Density

Porosity

26

APPENDIX B

Test Procedures, Calibration, and Data-AcceptanceCriteria for Thermal-Conductivity Measurements

A schematic of the thermal-conductivity test set-up is shown in Figure B-i. As shown, a 0.32-cm-dia.heater approximating an ideal line source is placedalong the longitudinal axis of a 5.1-cm-dia. by10.2-cm-long sample. A thermocouple is attached andsoldered to the heater at midsample. The entire probeassembly is "potted" in place with a mixture of ceram-ic cement and powdered copper to minimize andstandardize contact resistance between probe andsample. Disks of low-conductivity ceramic insulator X UPPERWSEAL

are used to minimize heat loss from the ends of thesample. Such heat losses, if unchecked, would lead to PRESSURE

anomalously high apparent conductivities. The over- VESSEL

all internal heater length, 13.4 cm, gives a heater OUTER HEATERSHROUD

length-to-diameter (L/D) ratio of 36. The L/3 ratio /, \iDwithin the sample itself is 32. The sample-probe as- SINER HEATER

sembly is separated from the confining fluid by a A__SPACER

teflon sleeve. /Power, in the form of carefully monitored and SAMPLE

controlled voltage and current, is applied to the probe PROBE HEATER

heater for periods of <2 min, while the exterior of the ASSEMBLY

sample is maintained at constant pressure and nearly CERAMIC SPACER

constant temperature (AT <1 0C). Because the exteri- LOWER ENOCAP

or temperature of the sample does not change signifi- SAMPLE HEATER

cantly during the period of the test, a sample of finite LE HETER

dimension behaves as if it were inifinite in volume. HEATER SHROUD BAFFLE

Thermal conductivity for the material is calculat-ed from the internal heater temperature history andpower input according to

47rAT tj1 ELECRCAL FEED

by determining the least-squares best fit to the experi-___LOWER SEALmental data between 30 (tj) and 90 (t2) s. In the ASSEMBL

equation, K is the rock thermal conductivity inW/m 0C, AT the change in heater temperature be-tween times t1 and t2, and P the heater power in W/m. Figure B-1 Schematic of Thermal-Conductivity Test Setup

27

I

Figure B-2 is a temperature -In(t) plot from arepresentative thermal-conductivity measurement.Note that the initial response of the heater is not log-linear. At longer times, beginning 20 to 30 s into thetest, the response is log-linear. In Figure B-3, tempera-ture is plotted against time on a linear time scale. Thisfigure emphasizes the short duration of the earlytransient period.

on the actual conductivity. At longer times, however,the assumption of infinite volume of the test samplebreaks down as the temperature at the outside of thesample rises. This condition, like end effects, results intoo high an apparent conductivity. Tests affected byvery-near-field contact resistance are identified by an"s-shaped" or sygmoidal time-In t response (FigureB-4), in contrast to standard or nominal curves (Fig-ure B-2). Test showing this type of curvature, -15%of the total number of runs, are disregarded here.

, .'

tn 01.1 Aft., H"-t. Tr.-On

Figure B-2 AT-in Time Plot, Representative ConductivityTest

In 11.1 Aft.r H1t*r Turn-Of

Figure B-4 AT-in Time Plot, Abnormal Conductivity Test

10

*0

Ep rimntal Data

0 20 40 60 80 100 120

Tin, 1.) Aft., H.,., Turn.On

Figure B-3 AT-Time Plot for Data Shown in Figure B-2

Several sources of error are possible in these mea-surements. In some tests, contact resistance may de-velop between heater and rock, generally at highertemperatures. This may be reflected by either ananomalously low apparent thermal conductivity in theearly portion of the time-temperature curves, or by anextended transient period. At longer times, as thevolume effectively integrated in the measurementsincreases, the apparent conductivity should converge

Most of the atypical runs occurred in high-temperature measurements on either zeolitized non-welded tuffs, or on devitrified welded tuffs from abovethe water table. In both cases, the source of theproblem appears to be related to mineralogy.1 Zeoli-tized nonwelded tuffs contract when dehydrated,while devitrifed welded tuffs above the water tablefrequently contain cristobalite, which goes through alarge volume increase in the vicinity of 1500 to 2000C.Either behavior could result in size changes in thecentral heater hole, and development of very-near-field contact resistance. In other cases, contact resis-tance might be related to fluid movement duringsample dehydration. More detailed discussion ofcontact-resistance effects and other potential errors intransient-line-source measurements are beyond thescope of this report.

The accuracy of conductivity data generated bythe transient-line-source technique depends upon theaccuracy of the power factor, P, used in calculations.

28

This factor can be determined by two methods.First, the power supplied to the heater probe duringthe test can be determined by monitoring appliedvoltage and current, and the power factor calculatedfrom known power input and heater length. The sec-ond approach involves testing a material of knownthermal conductivity and calculating the power factorfrom known conductivity and measured temperaturehistory of the heater probe.

Although no material has been adopted by theNational Bureau of Standards as a standard for ther-mal conductivity in the range 0.5 to 4 W/m0C, fusedsilica has been used by many as an unofficial standard(see, for example, Ref 18). Terra Tek uses a GE No.124 fused silica as standard. Samples of silica wereprepared and tested exactly like samples of tuff,.usingthe sample pressures, temperatures, and stabilizationtimes. Sample geometries are identical, and the heaterprobe, potting material, endcaps, and jacket materialsare the same for the fused silica as for the tuff samples.

Power factors in this study were routinely checkedby measurements on fused silica before and after eachtest series, assuming an ambient-temperature conduc-tivity of 1.33 W/m 0C for the silica. Power factors werealso calculated during calibrations at room tempera-ture and pressure by monitoring power input. Factorsdetermined by power monitoring and by measure-ments on fused silica agree to within + 1 %. Thisindicates that heater performance was stable, andthat, unless there is systematic error in the powermonitoring, the conductivity of the fused silica is near1.33 W/m 0C.

A total of 73 measurements on fused silica weremade for this study. Each assumes a constant moni-tored heater power factor of 130.4 to 137.0 W/m,depending upon heater. Table B-1 summarizes theresults. The measured "room-temperature" thermalconductivity of the fused-silica standard, based on 25tests and assuming predetermined power factors, is1.326 ± 0.025 W/m0 C.

Touloukian, et all9 have compiled literature valuesfor thermal conductivity of fused silica. As shown inFigure B-5, their "recommended" conductivity offused silica, which they believe to be accurate towithin ±3% over the temperature range shown,"in-creases from 1.33 W/mWC at 00C to 1.45 W/m0 C at770C, 1.57 W/m0C at 1770C, and 1.62 W/m0C at2270C. Both the fused-silica conductivities measuredin this study and their trend with increasing tempera-ture closely parallel data reported by Touloukian et alexcept near 1650C. At all other temperatures, thevalues reported here are the same as reported by

Touloukian to within the estimated precision. This isstrong confirmation of both the technique and heaterpower factors used here.

Table B-1 Measured Thermal Conductivityof GE No. 124 Fused Silica

Initial Temperature, T(0C)23 100 165 212 260

Thermal Conductivity, K(W/m0C)1.33 1.47 1.60 1.65 1.591.31 1.47 1.61 1.68 1.601.35 1.38 1.58 1.61 1.591.34 1.39 1.58 1.63 1.591.33 1.43 1.57 1.53 1.591.31 1.44 1.56 1.53 1.601.29 1.41 1.57 1.54 .1.571.30 1.44 1.62 1.58 1.641.30 1.44 1.60 1.55 1.611.33 1.60 1.44 1.591.29 1.59 1.461.34 1.62 1.541.29 1.581.35 1.521.35 1.571.35 1.561.37 1.561.361.331.311.361.281.321.331.33

Measurements 25 9 12 17 10Average K 1.33 1.43 1.59 1.56 1.601 Std. Dev. 0.03 0.03 0.02 0.06 0.02

Three additional conductivity measurements onthe standard material used in this study were made inan attempt to provide experimental confirmation ofthe standard's conductivity. Materials tested were cutfrom the same piece of silica. One sample was analyzedby Dyna Tech, Inc, in a divided-bar apparatus. Re-sults are shown as Curve 3 in Figure B-5. The conduc-tivities reported by Dyna Tech at low temperatures

29

fall very slightly below both those reported here andby Touloukian (1.29 vs 1.33 and 1.37 W/m0 C at 250C;1.41 vs 1.43 and 1.48 W/mWC at 1000C). At highertemperatures, the conductivity reported by DynaTech exceeds both the values of Touloukain and thosemeasured here. Measurements at Sandia, also by thedivided-bar technique, indicate a conductivity of theGE fused silica of 1.23 W/m1C at 300C, increasing to1.57 W/m0 C at 2500C. An additional measurement,made by J. Sass, USGS, Menlo Park, California, bythe transient-line-source method is also included inFigure B-5. He reports a conductivity of 1.33 W/mWCat 250C.

1.90 1. Terra Tek2. Touloukian at at'9

1.80 3. Dyna Tech4. Sandia5. USGS

1.70 /

1.60

1.50

aC

0 100 200 300T (VC)

Figure B-5 Thermal Conductivity of Fused Silica

Several conclusions appear justified by these re-suIts. First, the ambient-temperature thermal con-ductivity of the fused-silica standard used is appar-ently quite near the assumed value of 1.33 W/m0 C.1.31 ± 0.06 W/m°C is the average of the four measuredvalues and the value recommended by Touloukian. Atall temperatures, the total spread between values isonly about 10% of the average. Second, the trends ofconductivity vs temperature measured here and re-ported by Touloukian are consistent. Divided-bar re-sults at both Dyna Tech and Sandia indicate a morerapid increase in conductivity with increasing tem-perature. Finally, the use of ceramic cement and pow-dered copper as a potting compound in these measure-ments does apparently minimize contact resistancebetween heater and sample at most temperatures.

Measurements at 1650C in this study, however,are distinctly inconsistent with those at both higherand lower temperatures. The average rise in tempera-ture during the tests was 130 to 300C, and the boilingpoint of water at the fluid pressures used was near2000C. Thus, at least a portion of the cement-copperpotting mixture was raised to temperature of 1800C orgreater during tests at "165oC." The cement-copperpotting mix contains water. One possible reason forthe apparently higher thermal conductivity near1650C is that part of the water in the potting mixturevolatilized at these temperatures, consuming energy.

In this study, it is assumed that the thermalconductivity of the fused silica increases smoothlywith increasing temperature, as shown by the resultsof Touloukian, that the discrepancy in measurementsat 1650C is due to processes in the heater/pottingmaterial only, and that the real conductivity of theTerra Tek standard at 1650C is 1.51 W/m0C insteadof the measured value of 1.59 W/m0 C. This is adifference of 0.08 W/m0C. Tuff conductivities at1650C are, therefore, decreased below the measuredvalue by 0.08 W/m 0C in all data tables and figures.

I.

30

APPENDIX C

Individual Thermal-Conductivity Test Results

Individual test results, both of runs accepted hereand of discarded runs (see Appendix B), are includedin this appendix. In all cases, the conductivity listed isthat computer-calculated as the best fit for the time-delta temperature plot between 30 and 90 secondsafter heater turn on. Raw data and computer plots ofeach individual test have been provided to SandiaNational Laboratories Quality Assurance by TerraTek, Inc, Salt Lake City.

Table C-1 Thermal-Conductivity Test Results, Topopah Springs Member, Paintbrush Tuff

Thermal Conductivity (W/m0C)

IndividualTemperature (0C) Measurements Average

Sample 795 Grain Density = 2.52 g/cm3; Porosity = 0.11

23 (P, = Ps = 0.1 MPa) 2.12, 2.16 2.14(P0 = 10 MPa, Pf = 1.5 MPa) 2.14, 2.15 2.15

100 (All other tests at Pc = 10 MPa, Pf = 1.5 MPa) 2.13, 2.16 2.15165 2.05, 2.04* 2.05*205 1.38,** 1.30**270 1.21,** 1.44*

Sample 1330 Grain Density = 2.38 g/cm3; Porosity = 0.03

23 (All tests at P, = 10 MPa, 1.17, 1.18 1.18Pf = 1.5 MPa)

100 1.24, 1.24 1.24165 1.27, 1.28* 1.28*205 1.28, 1.28 1.28280 1.33 1.33

*Decreased by 0.08 W/m0C from raw data as discussed in Appendix B.**This test shows double curvature in T-t plots. Data disregarded, see Appendix B.

31

Table C-2 Thermal-Conductivity Test Results, Tuffaceous Beds of Calico Hills

Thermal Conductivity (W/m0 C)Individual

Temperature (0C) Measurements AverageSample 1503 Grain Density = 2.48 g/pm3; Porosity = 0.38

23 (P, = Pf= 0.1 MPa) 1.29, 1.30 1.30(P, = 10 MPa, Pf = 1.5 MPa) 1.30, 1.30 1.30

100 (All other measurements at 1.32, 1.35 1.34P, = 10 MPa, Pf = 1.5 MPa)

165 1.22, 1.34* 1.28*205 0.97, 1.17** 0.97250 0.97,** 1.02 1.02

Sample 1706 Grain Density = 2.33 g/cm3; Porosity = 0.33

23 (P, = Pf = 0.1 MPa) 1.16, 1.15 1.16100 (All other measurements at 1.20, 1.21 1.21

P, = 10 MPa, Pf = 1.5 MPa)165- 1.22, 1.25* 1.24210 0.86,** 0.83,** 1.24

0.82,** 0.65**

*Reduced by 0.08 W/m0C as discussed in Appendix B.**This test shows double curvature in T-t plots. Data disregarded.

I

32

Table C-3 Thermal-Conductivity Test Results, Prow Pass Member, Crater Flat Tuff

Thermal Conductivity (W/m 0 C)

IndividualTemperature (0 C) Measurements Average

Sample 2010 Grain Density = 2.40 g/cm3; -Porosity = 0.28 -- ^ - -- x

23 (PC = Pf = 0.1 MPa)(PC = 10 MPa, Pf = 1.5 MPa)

100 (All other measurements atPc = 10 MPa, Pf = 1.5 MPa)

165212

280

Sample 2070 Grain Density = 2.41 g/cm3; Porosity = 0.29

23 (PC = Pf = 0.1 MPa)(Pr = 10 MPa, Pf = 1.5 MPa)

100 (All other measurements atPC = 10 MPa, Pf = 1.5 MPa)

165212245

0.93,1.27,1.36,

0.97*1.291.40

1.281.38

1.46,1.41jt1.21tt0.91,

1.38* *1.35,tt

1.42**1.32

0.93 0.92

1.321.341.43

1.321.341.43

1.47**1.000.91

1.47**1.000.91

*Increase in conductivity with pressure indicates ambient-pressure test affected by either contact resistance or smple collapse.Data disregarded.**Reduced by 0.08 W/m0 C from raw data as discussed in Appendix B.tSomewhat suspect, long-time fit not good.ttlncomplete dehydration?

i .,.

33

Table C-4 Thermal-Conductivity Test Results, Central Nonzeolitized Portion of BullfrogMember, Crater Flat Tuff

Thermal Conductivity (W/m°C)Individual

Temperature (°C)Sample 2367.9A Grain Density - 2.59 g/cm3 ; Porosity = 0.25

23 (All at P, = 10 MPa,Pf = 1.5 MPa)

100165205280

Sample 2367.98

23 (P, = Pf = 0.1 MPa)(P, = 10 MPa, Pf = 1.5 MPa)

100 (All other measurements atP= 10 MPa, Pf = 1.5 MPa)

165212280

Measurements Average

1.88, 1.87 1.88

1.841.76,1.12,1.09,

1.58,1.64,1.53,

1.82*1.16**1.20**

1.841.79*1.121.09

1.621.641.57**

1.601.641.53

1.18,** 1.21**0.67,** 0.62**0.69**

Sample 2472.3 Grain Density = 2.62 g/cm3; Porosity = 0.32

23 (All at P, = 10 MPa,Pf = 1.5 MPa)

100165

1.89, 1.87 1.88

1.82,1.81,1.86*1.10,1.15,

206260

Sample 2473.1 Grain Density = 2.62 g/cm3; Porosity = 0.29

23 (All at Pc = 10 MPa,Pf = 1.5 MPa)

100165206260

1.851.87,

1.181.15

1.77,

1.741.76*1.051.03

1.841.85*

1.141.15

1.79,1.791.74,1.75,1.04,1.03,

1.79

1.741.76*1.051.03

Sample 2474.0 Grain Density = 2.62 g/cm3 ; Porosity = 0.31

23 (All at P. = 10 MPa,Pf = 1.5 MPa)

100

165

212260

1.71,1.73,1.711.70,1.701.69,1.68*1.05,1.04,

1.72,1.72,

1.71,

1.71,

1.72

1.70

1.69*

1.061.04

1.061.04

34

Table C-4 (cont)

Thermal Conductivity (W/m0 C)

IndividualTemperature (MC) Measurements Average

Sample 2493A Grain Density = 2.62 g/cm3; Porosity = 0.27

23 (P0 = Pf = 0.1 MPa) 1.70,** 1.71,**1.70**

(P, = 10 MPa, Pf = 1.5 MPa) 1.70**100 (All other measurements at 1.85, 1.91 1.88

P0 = 10 MPa, Pf = 1.5 MPa)165 1.59, 1.63* 1.61*

Sample 2493B

23 (P, = Pf = 0.1 MPa) 1.86, 1.88 1.87(P0 = 10 MPa, Pf = 1.5 MPa) 1.92, 1.85 1.89

100 (All other measurements at 1.90, 1.89 1.90P, = 10 MPa, Pf = 1.5 MPa)

165 1.85, 2.00* 1.93*205 1.14, 1.16 1.15280 1.15, 1.18 1.17

Sample 2536 Grain Density = 2.65 g/cm3 ; Porosity = 0.22

23 (P0 = Pf = 0.1 MPa) 1.73, 1.77t(P0 = 10 MPa, Pf = 1.5 MPa) 1.90, 1.89 1.90

100 (All other measurements at 1.79, 1.91 1.85P, = 10 MPa, Pf = 1.5 MPa)

165 1.84* 1.84*212 1.33, 1.35** 1.33280 1.29, 1.32 1.31

*Reduced by 0.08 W/m0 C from raw data as discussed in Appendix B.**This test shows double curvature. Data disregarded.Increase in conductivity indicates confined tests either not fully saturated or affected by contact resistance. Data disregarded.

35

Table C-5 Thermal-Conductivity Test Results, Zeolitized Portion of Bullfrog Member,Crater Flat Tuff

Thermal Conductivity (W/m°C)

IndividualMeasurements A-Temperature (0C)

Sample 2274.4 Grain Density = 2.36 g/cm3; Porosity = 0.34

23 (PI = Pf = 0.1 MPa)(PI = 10 MPa, Pf = 1.5 MPa)

100165212

Sample 2310 Grain Density = 2.44 g/cm3; Porosity = 0.37

23 (PI = Pf = 0.1 MPa)

(PI = 10 MPa, Pf = 1.5 MPa)100165212

260

Sample 2311 Grain Density = 2.41 g/cm3; Porosity = 0.36

23 (PI = Pf = 0.1 MPa)(P, = 10 MPa, Pf = 1.5 MPa)

100165215

260

Sample 2568.1 Grain Density = 2.41 g/cm3; Porosity = 0.32

23 (P. = Pf = 0.1 MPa)(PI = 10 MPa, Pf = 1.5 MPa)

100

165215260

verage

1.371.371.411.42*1.09

1.371.371.411.42*1.09

1.39,1.361.371.43,1.42,1.08,1.07,1.04,

1.39, 1.38

1.37,1.431.44*1.091.071.05

1.371.431.43*1.08

1.05

1.371.391.43,1.43,1.11,t1.00,1.000.95,

1.441.45*1.02,1.02,

0.97

1.371.391.441.44*1.01

0.96

1.33,1.35,1.40,1.43,1.47,1.07,1.03,

1.341.351.38,1.421.46*1.061.03

1.341.351.41

1.47*1.061.03

Sample 2569 Grain Density = 2.44 g/cm3 ; Porosity = 0.32

23 (PI = Pf = 0.1 MPa)(PI = 10 MPa, Pf = 1.5 MPa)

100165215260

1.38,1.33,1.42,1.45,1.18,1.15,

1.401.351.421.43*1.191.15

1.391.341.421.44*1.191.15

*Reduced by 0.08 W/m°C from raw data as discussed in Appendix B.tSingle high value apparently due to incomplete sample dehydration and disregarded in averaging.

36

Table C-6 Thermal-Conductivity Test Results, Tram Member, Crater Flat Tuff

Thermal Conductivity (W/m°C)

IndividualTemperature (°C) Measurements Average

Sample 2701.2 Grain Density = 2.42 g/cm3 ; Porosity = 0.31

23 (P, = Pf = 0.1 MPa)(P, = 10 MPa, Pf = 1.5 MPa)

100

165212245

1.381.401.441.45*1.20**1.02

1.381.401.441.45*

1.20**1.02

Sample 2814 Grain Density = 2.63 g/cm3 ; Porosity = 0.24

23 (P. = Pf = 0.1 MPa)(P, = 10 MPa, P. = 1.5 MPa)

100165205280

Sample 2842 Grain Density = 2.53 g/cm3 ; Porosity = 0.19

23 (P, = Pf = 0.1 MPa)(PC = 10 MPa, Pf = 1.5 MPa)

100165

205

280

Sample 2928.3 Grain Density = 2.65 g/cm3 ; Porosity = 0.19

23 (P, = 10 MPa, Pf = 1.5 MPa)100

165212260

2.27,2.23,2.21,2.14,1.60,t1.38,

2.302.242.262.10*1.46t1.41

2.282.242.242.12*

1.40

1.77,t1.75,1.78,1.71,1.90,t0.78,t0.71,t0.77,t0.78,t

1.70t1.781.761.50,1.760.79,t0.73,t0.77t0.16t

1.771.771.66

2.06,2.01,2.012.00,1.54,1.52,1.52

2.082.03,

2.072.02

2.02*1.561.53,

2.01*1.551.52

37

Table C-6 (cont)

Thermal Conductivity (W/m0C)

IndividualMeasurementsT'pmnprature (0C) Average

Sample 2938.8 Grain Density = 2.64 g/cm3; Porosity = 0.18

23 (P, = Pf = 0.1 MPa)(P0 = 10 MPa, Pf 1.5 MPa)

100

165

212

260

Sample 3050 Grain Density = 2.59 g/cma; Porosity = 0.25

23 (P0 = Pf = 0.1 MPa)(P0 = 10 MPa, Pf = 1.5 MPa)

100165212245

2.08,2.09,2.05,2.11,2.062.02,2.08*1.69,t1.58,1.59,t1.57,1.56

2.112.092.09,2.07,

2.102.092.08

;� 16.

2.07, 2.06*

1.59,t1.54,1.69,t1.57

1.57

1.56

1.941.961.981.98*1.77**1.53

1.941.961.981.98*1.77**1.53

*Decreased by 0.08 W/m°C from raw data as discussed in Appendix B.**Incomplete dehydration?tThis test shows double curvature in T-t plot. Data disregarded.

38

Table D-2 Bulk-Property Measurements, Tuffaceous Beds of Calico Hills

1. Initial density (g/cM3)2. Dry bulk density (glcm3)3. Grain density (g/cm3

)

4. Relative weight fraction of water (on basis of initial density)5. Porosity (calculated)6. Saturation (calculated)7. Bulk density at full saturation (calculated, g/cm3)

Sample Lithologic TypeDepth (ft) 1 2 3 4 5 6 7 (Generalized from Ref 1)

1469.9 1.89 1.53 2.41 0.19 0.37 0.97 1.89 Nonwelded ashflow1503.0 1.85 1.53 2.48 0.21 0.38 0.84 1.921505.0 1.86 1.57 2.28 .0.16 0.31 0.94 1.881514.8 1.93 1.60 2.40 0.17 0.33 1.00 1.941553.0 1.76 1.49 2.30 0.16 0.35 0.77 1.85 Nonwelded ashflow1571.2 1.85 1.47 2.40 0.21 0.39 0.97 1.85 Nonwelded ashflow1606.0A 1.86 1.51 2.47 0.19 0.39 0.90 1.901606.OB 1.71 1.55 2.24 0.10 0.31 0.52 1.861606.0C 1.71 1.56 2.24 0.09 0.30 0.50 1.871606.0D 1.77 1.53 2.25 0.13 0.32 0.75 1.851652.0A 1.70 1.53 2.38 0.08 0.36 0.47 1.881652.OB 1.88 1.57 2.33 0.20 0.33 0.94 1.891663.5 1.95 1.63 2.45 0.17 0.33 0.97 1.971667.0 1.92 1.58 2.44 0.18 0.35 0.97 1.941705.5 1.88 1.57 2.33 0.16 0.33 0.94 1.89 Nonwelded ashflow1722.3 1.93 1.58 2.48 0.18 0.36 0.97 1.951784.5 2.24 2.00 2.62 0.11 0.24 1.00 2.24 Bedded/reworked,

including tuffaceoussandstone

40

Table D-3 Bulk-Property Measurements, Prow Pass Member, Crater Flat Tuff

1.2.3.4.5.6.7.

Initial density (g/cm3)Dry bulk density (g/cm3)Grain density (g/cm3)Relative weight fraction of water (on basis of initial density)Porosity (calculated) ,Saturation (calculated)Bulk density at full saturation (calculated, g/cm3)

SampleDepth (ft)

Lithologic Type7 (Generalized from Ref 1)1 2 3 4 5 6

1832.0A1832.0B1847.OA1847.0B1886.01926.61930.01947.01948.01973.72010.OA2010.OB2050.02052.02064.92065.02066.02067.02070.02086.02113.02128.02151.02170.OA2170.OB

1.881.881.911.912.091.972.012.071.912.052.031.931.981.981.891.931.982.031.961.891.991.922.002.052.07

1.551.521.561.561.771.781.671.961.901.751.781.661.711.671.731.671.691.751.721.641.691.651.741.781.82

2.382.372.422.462.592.632.552.512.562.522.372.422.382.462.372.362.392.432.412.402.382.412.352.462.47

0.170.19

.0.180.190.150.100.170.080.010.150.140.140.140.160.090.130.150.140.120.140.150.140.130.130.12

0.350.360.360.370.320.320.350.220.260.310.250.310.280.320.270.290.290.280.29

I 0.320.290.320.260.280.27

0.941.000.970.951.000.590.970.500.040.971.000.870.960.970.590.901.001.000.830.781.030.841.000.960.96

1.901.881.911.922.082.112.012.182.152.052.031.981.991.992.001.971.982.032.001.951.981.962.002.052.07

Partially weldedashflow; devitrified

Partially to moderatelywelded ashflow;devitrified

Partially weldedashflow; devitrified

Partially to moderatelywelded ashflow;devitrified

Bedded/reworked, withtuffaceous sandstone

" � i

. I ,

I L : )

41

Table D-4 Bulk-Property Measurements, Bullfrog Member, Crater Flat Tuff

1. Initial density (g/cm3)2. Dry bulk density (g/cm3 )3. Grain density (glcm3 )4. Relative weight fraction of water (on basis of initial density)5. Porosity (calculated)6. Saturation (calculated)7. Bulk density at full saturation (calculated, g/cm3 )

-

SampleDepth (ft)

2192.02206.02227.02232.02261.02265.02273.42274.4A2274.4B2276.02285.02286.02310.2A2310.2B2310.8A2310.8B2311.5A2311.5B2312.02313.02321.OA2321.OB2321.OC2321.0D2321.OE2321.OF2332.02338.OA2338.OB2338.OC2338.0D2338.OE2338.0F2338.OG2338.OH2355.02355.92367.92371.02380.0

1

1.991.911.861.821.891.881.911.851.891.921.871.881.851.871.881.871.851.901.871.851.911.901.921.891.931.901.961.951.951.962.001.981.971.981.982.072.122.122.172.17

2

1.701.641.501.501.541.551.571.581.561.581.521.541.511.511.541.511.511.571.521.491.611.621.631.601.631.611.641.601.611.621.661.641.631.661.661.841.871.951.911.93

3

2.462.432.442.442.412.442.432.312.402.402.402.392.402.472.392.482.352.472.372.422.542.542.542.542.562.582.582.652.692.672.692.662.702.622.662.642.602.592.622.55

Lithologic Type(Generalized from Ref 1)4

0.150.140.200.200.190.180.180.170.180.180.190.180.180.190.180.200.180.170.190.200.160.170.180.180.180.150.170.180.180.170.170.170.170.160.170.110.130.080.120.11

5

0.310.330.390.390.360.360.350.320.350.340.370.360.370.390.360.390.360.360.360.390.370.360.360.370.370.380.370.400.400.390.390.380.400.370.380.300.280.250.270.24

6

0.940.820.920.970.980.920.970.840.941.000.950.940.920.920.940.920.940.920.990.920.810.780.810.780.810.760.860.880.850.870.870.890.850.860.840.770.890.680.960.99

7

2.011.961.881.881.901.921.931.891.911.001.881.891.881.901.891.901.861.941.881.871.971.991.991.971.981.982.001.992.012.022.032.032.022.022.032.152.152.192.182.18

Nonwelded ashflow;devitrifiedNonwelded to partiallywelded ashflow

Partially welded ash-flow; vapor phase zone

-.

42

Table D-4 (cont)

SampleDepth (ft) 1 2

Lithologic Type7 Ir--~rsl-vA Ntr o

3 4 5 6;

2382.92385.3A2385.3B

2385.3D2385.3E2392.02405.02405.82414.OA2414.OB2428.OA2428.OB2428.OC2428.01)2428.OE2428.OF2428.OG2428.0112428.012428.OJ2428.0K2429.OA2429.0B2445.02468.02472.3A2472.3B2472.5A2472.5B2473.5A2473.5B2474.OA2474.0B2480.02485.62493.OA2493.0B2501.02509.02510.02517.02518.02530.02536.2A2536.2B2538.02549.0

4 i- - J J1 i I .V 1 1 )

''

2.182.17

'f2 15

2.132.122.212.182.182.142.142.082.102.132.142.132.142.102.102.081.952.142.172.162.202.152.062.022.142.182.112.132.062.082.182.202.152.172.212.222.172.292.272.282.192.272.201.92

1.921.931.941.891.901.881.951.921.931.861.881.831.861.871.891.821.891.871.871.831.721.891.901.891.951.941.811.741.891.931.871.881.811.831.941.971.911.941.992.021.952.102.072.092.032.111.971.69

2.602.662.652.64

-2.612.642.622.612.592.612.572.622.622.652.622.642.642.622.612.622.632.632.622.602.632.602.602.642.632.652.612.632.622.622.612.572.622.612.612.622.542.622.602.612.662.632.582.48

0.120.110.110.110.110.110.120.120.120.130.120.140.130.140.130.130.140.120.120.140.130.130.130.130.110.130.140.120.120.110.110.120.120.120.110.110.130.120.100.090.100.080.090.080.080.100.110.12

0.260.270.270.280.270.290.260.260.250.290.270.300.290.290.280.310.280.290.280.300.350.280.280.270.260.280.300.340.280.270.280.290.310.300.260.230.270.260.240.230.230.200.200.200.240.200.240.32

1.000.890.780.820.850.831.001.001.000.970.960.830.830.900.891.000.890.790.820.830.660.890.991.000.960.990.830.820.890.930.860.860.810.830.921.000.890.880.920.870.940.951.000.950.670.800.990.72

2.182.212.202.182.182.162.212.182.182.142.152.132.152.172.172.132.182.152.162.132.062.172.172.162.212.15 Moderately to densely2.12 welded ashflow;2.08 devitrified2.172.202.162.162.122.132.192.202.182.192.222.252.192.302.272.292.262.30 Moderately to partially2.20 welded ashflow;2.01 devitrified

.5-

43

Table D-4 (cont)

SampleDepth (ft)

Lithologic Type7 (Generalized from Ref 1)1 2 3 4 5 6

I2550.02551.52561.02563.02568.1A2568.1B2568.7A2568.7B2569.1A2569.1B2585.02587.02588.02607.02608.0

2.052.072.092.151.961.961.951.971.921.952.042.042.052.062.12

1.801.871.861.941.691.681.701.681.671.661.811.791.791.821.89

2.432.462.432.472.362.462.382.532.382.492.392.442.442.442.47

0.120.100.110.100.140.140.130.150.130.150.110.130.130.120.11

0.260.240.230.210.280.320.290.340.300.330.240.270.270.250.24

0.970.831.000.980.960.880.860.850.830.880.950.930.960.960.98

2.062.112.092.161.981.991.982.011.972.002.062.052.052.082.12

Bedded/reworked tuff

Table D-5 Bulk-Property Measurements, Tram Member, Crater Flat Tuff

1.2.3.4.

Initial density (g/cm3)Dry bulk density (g/cm3)Grain density (g/cm3)Relative weight fraction of water (on basis of initial density)

5. Porosity (calculated)6. Saturation (calculated)7. Bulk density at full saturation (calculated, g/cm3)

SampleDepth (ft)

Lithologic Type7 (Generalized from Ref 1)1 2 3 4 5 6

2641.02653.02658.42658.62658.82659.02659.42691.02701.2A2701.2B2725.02761.02794.02814.OA2814.0B2814.OC2814.OD2830.0

2.072.001.972.021.962.081.922.091.961.962.032.152.292.212.162.232.212.25

1.801.711.691.791.701.861.701,871.701.671.741.892.112.001.962.072.032.04

2.492.442.442.312.322.372.392.432.422.412.442.612.632.632,642.642.612.64

0.130.150.170.120.140.170.120.110.150.150.140.120.080.100.100.080.090.10

0.280.300.310.230.270.220.290.230.300.310.290.280.200.240.260.220.220.23

0.990.970.901.000.961.000.760.960.870.941,000.930.900.880.770.730.820.91

2.072.011.992.021.962.081.992.101.991.972.032.162.302.242.212.282.262.26

Partially to moderatelywelded ashflow;devitrified

44

Table D-5 (cont)

SampleDenth (ft)

Lithologic Type6 7 (Generalized from Ref 1)1 2 3 4 5

2842.02847.82861.02897.0

.-2928AA:2928.1B2938.82939.32943.02952.02970.03006.03041.03050.OA3050.OB3051.0A3051.OB3084.03085.03102.03106.83107.43150.03173.63200.OA3200.OB3226.63251.03297.03325.83350.03400.03426.83448.03495.93498.0

2.252.352.232.262.3Y'2.322.312.342.372.412.322.282.132.132.112.382.312.202.302.132.112.112.242.332.322.332.312.292.322.312.342.372.352.362.392.38

2.062.181.992.05

2.17"2.142.142.182.212.292.152.081.891.971.892.242.111.972.101.871.881.882.052.152.152.172.112.082.132.092.162.202.182.172.202.18

2.532.622.642.64,2.6w2.652.632.642.632.642.642.612.522.612.572.612.622.612.632.502.502.482.582.652.612.632.642.632.622.682.622.682.702.712.752.72

0.090.070.110.09 f0.060.080.070.070.060.050.080.090.110.080.110.060.080.110.090.110.110.110.090.080.070.070.090.090.080.090.080.070.070.080.080.08

0.190.170.250.I2 80.190.190.190.170.160.130.190.200.250.250.270.140.190.250.200.250.250.240.210.190.180.170.200.210.190.220.180.180.190.200.200.20

1.001.000.960.25 80.78 .0.950.890.941.000.920.891.000.960.640.891.001.050.921.000.920.920.960.900.950.940.941.001.001.001.001.000.940.890.950.951.00

2.252.352.232.28),2.352.342.322.362.372.432.332.282.142.212.152.382.312.21 Partially welded ash-2.30 flow; zeolitized2.132.132.122.25 Nonwelded to partially2.34 welded ashflow;2.32 zeolitized and argillic2.352.312.292.322.312.342.382.382.372.402.38

45

References'R. W. Spengler, F. M. Byers, Jr, and J. B. Waren,

Stratigraphy and Structure of Volcanic Rocks in Drill HoleUSW-Gl, Yucca Mountain, Nye County, Nevada, US Geo-logical Survey, Open-File Report 81-1349, in preparation.

2R. W. Spengler, D. C. Muller, and R. B. Livermore,Preliminary Report on the Geology and Geophysics of DrillHole UE25A#1, Yucca Mountain, Nevada Test Site, USGeological Survey Open-File Report 79-1244 (Denver, CO:US Geological Survey, 1979).

3W. Woodside and J. H. Messmer, "Thermal Conduc-tivity of Porous Media," I. Unconsolidated Sands, J AppPhys 32:1688-98, 1961.

4P. W. Lipman, R. L. Christiansen, and J. T. O'Conner,A Compositionally Zoned Ash-Flow Sheet in SouthernNevada, US Geological Survey, Prof. Pap. 524-F (Washing-ton, DC: US Government Printing Office, 1966).

5M. L. Sykes, G. H. Heiken, and J. R. Smyth, Mineral-ogy and Petrology of Tuff Units From the UE25a-1 DrillSite, Yucca Mountain, Nevada, Informal Report LA-8139-MS (Los Alamos, NM: Los Alamos National Laboratory,1979).

6p. R. Carroll, and A. C. Waters, editors, PreliminaryStratigraphic and Petrologic Characterization of CoreSamples From USW-GI, Yucca Mountain, Nevada, Infor-mal Report LA-8840-MS (Los Alamos, NM: Los AlamosNational Laboratory, 1981).

7N. B. C. Yelamanchili, memo to A. R. Lappin, SNLAdtd. 10/23/80: "Thermal Conductivity of Tuff Samples,"Holmes and Narver, Inc, Materials Testing Laboratory,Nevada Test Site.

8N. B. C. Yelamanchili, memo to A. R. Lappin, SNLAdtd. 3/12/80: "Thermal Conductivity and Physical Proper-ties Test Results on Tuff Specimens from Drill HoleUE25A#1," Holmes and Narver, Inc, Materials TestingLaboratory, Nevada Test Site, Laboratory Report No. 584.

9A. R. Lappin, Thermal Conductivity of Silicic Tuffs:Predictive Formalism and Comparison With PreliminaryExperimental Results, SAND80-0769 (Albuquerque, NM:Sandia National Laboratories, 1980).

'0N. B. C. Yelamanchili, memo to A. R. Lappin, SNLAdtd. 7/31/79: "Thermal Conductivity Test on Tuff SamplesFrom UE25A#1 Drill Hole," Holmes and Narver, Inc, Mate-rials Testing Laboratory, Nevada Test Site, LaboratoryReport No. 2068.

"1F. M. Byers, Jr, et al, Volcanic Suites and RelatedCauldrons of Timber Mountain - Oasis Valley CalderaComplex, Southern Nevada, US Geological Survey, Prof.Pap. 919 (Washington, DC: US Government Printing Office,1976).

12J. H. Sass, A. H. Lachenbrush, and R. J. Munroe,"Thermal Conductivity of Rocks From Measurements onFragments and its Applications to Heat-Flow Determina-tions;" J Geoph Res 76:3391-3401, 1971.

13E. C. Robertson and D. L. Peck, "Thermal Conductiv-ity of Vesicular Basalt From Hawaii;" J Geoph Res 79:4875-88, 1974.

14W. Woodside and J. H. Messmer, "Thermal Conduc-tivity of Porou3 Media II. Consolidated Rocks;" J App Phys32:1699-1706, 1961.

15J. Kestin, "Thermal Conductivity of Water andSteam;" Mech Eng 100:46-48, 1978.

16E. R. G. Eckert and R. M. Drake, Jr, Analysis of Heatand Mass Transfer (New York: McGraw-Hill, 1972).

17A. R. Lappin, Preliminary Thermal ExpansionScreening Data for Tuffs, SAND78-1147 (Albuquerque,NM: Sandia National Laboratories, 1980).

18W. L. Sibbitt, J. G. Dodson, and J. W. Tester, "Ther-mal Conductivity of Crystalline Rocks Associated WithEnergy Extraction From Hot Dry Rock Geothermal Sys-tems," J Geoph Res 84:B.3, p 1117-24, 1979.

'9Y. S. Touloukian, et al, "Thermal Conductivity, Non-metallic Solids; Thermophysical Properties of Matter," V 2IFI/Plenum, New York, 1970.

46

DISTRIBUTION:

TIC-4500 (R69) UC-70 (325)

US Department of Energy (3)Office of Waste IsolationGermantown, MD 20767Attn: W. Ballard, Director

Rm B-207C. R. Cooley, Deputy Director

Rm B-214R. Stein, Actg Team Leader

Tech Team, Rm B-220

US Department of EnergyNational Waste Terminal Storage Program Office505 King Ave.Columbus, OH 43201Attn: J. 0. Neff, Program Manager

Lawrence Livermore National Lab (3)PO Box 808Livermore, CA 94550Attn: L. D. Ramspott

Technical Project Officer, MS L-204K. Street, Jr, MS L-209A. J. Rotham, MS L-204

Los Alamos National Lab (2)PO Box 1663Los Alamos, NM 87545Attn: B. R. Erdal

Technical Project Officer, MS 514D. C. Hoffman, MS 760

Westinghouse - AESDPO Box 708Mercury, NV 89023Attn: A. R. Hakl

Site Manager, MS 703

US Geological Survey (2)PO Box 25046Federal CenterDenver, CO 80301Attn: G. L. Dixon

Technical Project Officer, MS 954W. E. Wilson, MS 954

W. S. Twenhofel820 Estes StLakewood, CO 80226

US Department of EnergyRichland Operations OfficePO Box 550Richland, WA 99352Attn: R. G. Goranson

Rockwell International Atomics InternationalDivision

Rockwell Hanford OperationsRichland, WA 99352Attn: R. Deju

US Department of Energy (13)PO Box 14100Las Vegas, NV 89114Attn: R. M. Nelson, Director (3)

Waste Mgmt Project OfficeD. F. Miller, Director

Office of Public AffairsR. H. Marks, CP-1, MS 210B. W. Church, Director

Health Physics DivisionR. R. Loux (7)

Holmes & Narver, IncPO Box 14340Las Vegas, NV 89114Attn: A. E. Gurrola

Batelle (8)505 King AveColumbus, OH 43201Attn: Office of Nuclear Waste

Isolation, ForN. E. CarterS. Goldsmith

ONWI Library (5)Office of NWTS Integration For

W. A. Carbiener

State of NevadaCapitol ComplexGovernor's Office of Planning CoordinationCarson City, NV 89023Attn: R. M. Hill

State Planning Coordinator

47

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DISTRIBUTION (cont):

Department of EnergyState of NevadaCapitol ComplexCarson City, NV 89710Attn: N. A. Clark

Argonne National Labs9700 S. Cass Ave.Argonne, IL 60439Attn: A. M. Friedman

, I

International Atomic Energy AgencyDiv of Nuclear Power & ReactorsKarnter Ring 11PO Box 590, A-1011Vienna, AUSTRIAAttn: J. P. Colton

Reynolds Electrical & Engineering Co., IncMS 555PO Box 14400Las Vegas, NV 89114Attn: H. D. Cunningham

Fenix & Scisson, IncPO Box 15408Las Vegas, NV 89114Attn: J. A. Cross

141747004760476147624763476347634763476447645521553258245824821431413151

F. W. MullerE. H. BecknerR. W. LynchL. W. ScullyL. D. TylerJ. R. TillersonD. R. FortneyA. R. Lappin (32)R. M. ZimmermanR. C. LincolnA. E. StephensonR. K. ThomasR. H. PriceJ. A. KoskiM. MossM. A. PoundL. J. Erickson (5)W. L. Garner (3)

4.-

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