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WRIR 01-4210: Hydraulic-Property Estimates for Use With a Transient Ground-Water Flow Model of the Death Valley Regional Ground-Water Flow System, Nevada and California

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Table 2. Hydraulic conductivity distribution in Death Valley regional ground-water flow system hydrogeologic units

[Abbreviations: --, no data; m/d, meters per day; ACU, alluvial confining unit; BRU, Belted Range unit; CFVU, Crater Flat volcanic unit; ICU, intrusive confining unit; K, hydraulic conductivity in meters per day; LCA, lower carbonate aquifer; LCCU, lower clastic confining unit; LFU, lava flow unit; OAA, older alluvial aquifer; OVU, older volcanic unit; PVA, Paintbrush volcanic aquifer; SCU, sedimentary rocks confining unit; TMVA, Thirsty Canyon/Timber Mountain volcanic aquifer; TV, Tertiary volcanic rocks; UCA, upper carbonate aquifer; UCCU, upper clastic confining unit; VSU, volcaniclastic and sedimentary rocks unit; XCU, crystalline confining unit; YAA, younger alluvial aquifer; YVU, younger volcanic unit]

Hydrogeologic unit or subunit

Geometric mean K (m/d)

Arithmetic mean K (m/d)

Minimum K (m/d)

Maximum K (m/d)

95-percent confidence interval of geometric mean (m/d)

Number of analyses

YAA and OAA

2

11

0.001

130

0.6 - 4

43

ACU

3

11

.003

34

.6 - 10

13

LFU

--

--

.002

4

--

2

YVU and VSU

.06

1.5

.00004

6

.01 - .4

15
TV

.1

4

.000001

180

.08 - .2

159
    Rhyolitic to rhyodacitic lava flows

.1

.6

.000007

4

.04 - .4

25
    Ash-flow tuff

.1

5

.000002

180

.06 - .2

109
        Non-welded to partially welded

.06

7

.003

180

.03 - .2

43
        Partially to moderately welded

.04

1

.000002

19

.03 - .1

35
        Moderately to densely welded

2

13

.02

55

.18 - 15

7
        Unaltered  

8

.00002

180

.2 - .9

71
        Zeolitized and argillized

.04

1

.000002

25

.02 - .08

63
        Tuff breccia and ash-flow tuff

.3

 4

.0008

15

.03 - 3

11
        Bedded ash-fall and reworked
        tuff and ash-flow tuff

.1

 2

.00009

15

.03 - .7

14
    TMVA

 .01

 2

.0002

20

.001 - .01

11
    PVA

.02

4

.000007

22

.001 - .09

9
    CHVU

.2

.6

.008

2

.08 - .5

14
    BRU

.3

 1

.01

4

.06 - 2

6
    CFVU

.2

6

.000002

180

.09 - .3

91

OVU

.004

.07

.000001

1

.001 - .01

46

ICU

.01

.3

.0006

1

.001 - .01

7

SCU

.002

.02

.0002

.3

.0007 - .005

16

UCA and LCA

.6

 90

.00001

820

.2 - 2

51

    Faulted and karstic

3

120

.01

820

3 - 4

18

    Unfaulted

.1

2

.0001

14

.02 - .5

19

UCCU and LCCU

.00003

.2

.00000003

5

.000003 - .0003

30

UCCU (shales)

.01

.07

.0003

.4

.002 - .06

9

LCCU (quartzites)

.0000006

5

.00000003

 5

.00000007 - .000005

19

XCU

--

--

.00000002

1<.4

--

--

1 Based on the 14.5 percent upper confidence level of Bedinger and others (1989) weathered metamorphic rocks hydraulic conductivities, and the lower 14.5 percent estimate for deep unweathered metamorphic rocks. Confidence levels are based on the 50th percentile estimate of their sample.