Table 5. Stable isotopes of hydrogen, oxygen, carbon, and strontium in water collected from Cave Springs, a permanent pool in Lehman Caves, and two nearby springs at Great Basin National Park, Nevada.

[Site locations are shown in figure 2. Analyses were done by laboratories listed in table 2. Sample dates and times for sites 1–4 are listed in tables 3 and 4. Cave Springs prior to reconstruction of water-collection system: Analyses of Cave Springs water prior to reconstruction of water-collection system in 1996 are from Acheampong (1992). Average of 15 analyses from samples collected between August 15, 1990, and September 15, 1991. Environmental Isotope Laboratory of the Water Resources Center at the Desert Research Institute in Las Vegas, Nevada, did the analysis. Symbol: –, not determined]

Stable isotope	Site 1 Cave Springs	Site 2 Pool in Lehman Caves	Site 3 Spring near upper Lehman Creek campground	Site 4 Marmot Spring	Cave Springs prior to reconstruction of water system
Hydrogen-2/hydrogen-1 (2H/1H) as δD in permil1	-115	-94.2	-106	-113	-116
Oxygen-18/oxygen-16 (18O/16O) as δ18O in permil1	-15.5	-12.2	-14.7	-15.4	-15.7
Carbon-13/carbon-12 (13C/12C) as δ13C in permil2	-14.0	-10.0	-16.0	-15.0	–
Strontium-87/strontium-86 (87Sr/86Sr)3	0.71713	0.71121	0.71813	0.71271	–

¹ Ratios reported in delta (δ) notation as parts per thousand (permil). Delta is the relative difference between the ratios of hydrogen-2 or deuterium to hydrogen-1 (²H/¹H) or oxygen-18 to oxygen-16 (¹⁸O/¹⁶O) in water samples to the respective ratios in Vienna Standard Mean Ocean Water (VSMOW; Giofiantini, 1978). A negative value represents water with less ²H relative to ¹H or ¹⁸O relative to ¹⁶O than VSMOW. Standard error at 95-percent confidence level is 2 permil for δD and 0.2 permil for δ¹⁸O.

² Ratios reported in delta (δ) notation as parts per thousand (permil). Delta is the relative difference between the ratios of carbon-13 to carbon-12 (¹³C/¹²C) in water samples to that in a sample of belemnite from the Pee Dee Formation of South Carolina (PDB; Craig, 1957). A negative value represents a sample with less ¹³C relative to ¹²C than in the standard sample of PDB. Standard error at 95-percent confidence level is 0.5 permil.

³ Ratios are based on repetitive analyses on the seawater standard, EN-1. The error on the ratio of strontium-87 to strontium-86 (⁸⁷Sr/⁸⁶Sr) is ± 0.00005 at the 95-percent confidence level.