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U.S. GEOLOGICAL SURVEY
Data Series 280

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Table 7. Selected trace element concentrations and strontium isotopic compositions (⁸⁷Sr/⁸⁶Sr) in core samples from boreholes UE‑25 a #3 and UE-25 p #1, Nevada Test Site, Nye County, Nevada.

[Siliciclastic lithologies for samples from surface to 697.2-m depth in borehole UE–25 a #3 consist of Mississippian (middle Chester to early Osage stages) Chainman Shale and Gap Wash Formation (Maldonado and others, 1979; Cole and Cashman, 1998). Underlying core is undifferentiated Devonian carbonate (Du). Stratigraphic units for borehole UE–25 p #1 are from Carr and others (1986). Stratigraphic unit symbols are defined in table 1. Analysis type: WR indicates that strontium isotopic compositions (⁸⁷Sr/⁸⁶Sr) were determined on whole-rock digestions using concentrated hydrofluoric, nitric, hydrochloric, and sulfuric acids; HCl–L indicates that ⁸⁷Sr/⁸⁶Sr values were determined on dilute hydrochloric acid leachates of powdered rock samples. Strontium isotopic compositions are given in delta notation (δ⁸⁷Sr = [(⁸⁷Sr/⁸⁶Sr_sample/⁸⁷Sr/⁸⁶Sr_msw)-1]×1,000 and δ⁸⁷Sr_t = [(⁸⁷Sr/⁸⁶Sr_sample/⁸⁷Sr/⁸⁶Sr_psw)-1]×1,000, where ⁸⁷Sr/⁸⁶Sr_msw is the value for modern seawater and ⁸⁷Sr/⁸⁶Sr_psw is the value for paleoseawater at the time of deposition). Abbreviations and symbols: Rb, rubidium; Sr, strontium; Y, yittrium; Zr, zirconium; Nb, Niobium; Ba, barium; La, lanthanum; Ce, cerium; m, meter; ‰, per mil; ND, not determined]

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