Table 6. Stable isotopes of oxygen and carbon in rock sample of Pole Canyon Limestone and ratio of strontium isotopes and concentration of strontium in rock samples of Pole Canyon Limestone, Tertiary granite, and Prospect Mountain Quartzite near Cave Springs at Great Basin National Park, Nevada.

[Site locations are shown in figure 2. All rock samples were collected on September 8, 2007, between 7:45 and 9:30 AM Pacific Standard Time. Analyses were done by U.S. Geological Survey Yucca Mountain Project Environmental laboratory, Lakewood, Colorado. Symbol: –, not determined]

Stable isotope/ constituent in rock	Site 5 Pole Canyon Limestone	Site 6 Tertiary granite	Site 7 Prospect Mountain Quartzite
Oxygen-18/oxygen-16 (18O/16O) as δ18O in permil VSMOW1	2.0	–	–
Oxygen-18/oxygen-16 (18O/16O) as δ18O in permil PDB2	-28.0	–	–
Carbon-13/carbon-12 (13C/12C) as δ13C in permil PDB2	-0.82	–	–
Strontium-87/strontium-86 (87Sr/86Sr)3	0.71358	0.72695	0.75487
Strontium (milligrams per kilogram of rock)	240	47	6.6

¹ Ratio reported in delta (δ) notation as parts per thousand (permil). Delta is the relative difference between ratios of oxygen-18 to oxygen-16 (¹⁸O/¹⁶O) in sample of Pole Canyon Limestone to that in Vienna Standard Mean Ocean Water (VSMOW; Gonfiantini, 1978). A positive value represents a sample with more ¹⁸O relative to ¹⁶O than VSMOW. Standard error at 95-percent confidence level is 0.2 permil.

² Ratios reported in delta (δ) notation as parts per thousand (permil). Delta is the relative difference between the ratios of oxygen-18 to oxygen-16 (¹⁸O/¹⁶O) and carbon-13 to carbon-12 (¹³C/ ¹²C) in sample of Pole Canyon Limestone to the respective ratio in a sample of belemnite from the Pee Dee Formation of South Carolina (PDB; Craig, 1957). Negative values of δ¹⁸O and δ¹³C represent samples with less ¹⁸O and ¹³C relative to ¹⁶O and ¹³C in the standard sample of PDB, respectively. Standard error at 95-percent confidence level is 0.2 permil for δ¹⁸O and 0.5 permil for δ¹³C.

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.