Elemental concentrations and stable oxygen and carbon isotope ratios are reported for five mammillary calcite specimens collected from the groundwater-filled fissures Devils Hole and Devils Hole II in the southern Amargosa Desert, south-western Nevada. Previous studies of these specimens yielded oxygen and carbon isotope chronologies of paleoclimatic and paleo hydrologic conditions over an approximately 500,000-year time period as defined by uranium series dates (Winograd and others, 1992, 2006; Landwehr and others, 1997, 2011). The elemental concentration measurements reveal additional chronologies in the mammillary calcite. The specimens were sampled by milling contiguous 0.050-inch-thick layers (1.27 millimeters) oriented approximately parallel to the free, wetted growth faces of the specimens. For three of the five specimens (cores DH-10 and DH-11, hand specimen DH-7), the oxygen and carbon isotope measurements reproduce measurements of the same milled samples made by Landwehr and others (1997) and Coplen and others (2021). For the remaining specimens (hand specimens DHC2-3 and DHC2-8), the oxygen and carbon isotope measurements reproduce isotopic records published by Coplen and others (2021) but at a coarser resolution because Coplen and others (2021) analyzed milled layers of 0.010-inch thickness (0.25 millimeters). The elemental chronologies can be dated by referring to prior studies. For DH-11, uranium series dates and interpolated ages are given by Landwehr and others (1997). For DH-7 and DH-10, ages obtained by matching oxygen and carbon isotope chronologies to the dated chronologies of DH-11 are given by Coplen and others (2021). For DHC2-3 and DHC2-8, ages can be obtained by matching the oxygen and carbon isotope chronologies presented here to the higher-resolution dated chronologies provided by Coplen and others (2021). However, age assignments should be made with caution (see, for example, Moseley and others, 2016). Devils Hole and Devils Hole II are extensional tectonic fissures that open to the land surface adjacent to the major Ash Meadows ground-water discharge area. Devils Hole II is approximately 200 meters north of Devils Hole. The fissures intersect the regional groundwater table at about 17 meters and 36 meters below land surface at Devils Hole and Devils Hole II, respectively. These localities have long been important in paleoclimate research because mammillary calcite phreatically precipitated on the fissure walls has yielded a dated continuous paleotemperature proxy record that spans several glacial cycles (Winograd and others, 1988, 1992, 2006; Ludwig and others, 1992; Coplen and others, 1994; Riggs and others, 1994; Szabo and others, 1994; Plummer and others, 2000; Kolesar and Riggs, 2004; Moseley and others, 2016; Coplen and others, 2021). References listed chronologically: Winograd, I.J., Szabo, B.J., Coplen, T.B., and Riggs, A.C., 1988, A 250,000-year climatic record from Great Basin vein calcite: implications for Milankovitch theory: Science, v. 242, p. 1275-1280, doi: 10.1126/science.242.4883.1275. Ludwig, K.R., Simmons, K.R., Szabo, B.J., Winograd, I.J., Landwehr, J.M., Riggs, A.C., and Hoffman, R.J., 1992, Mass-spectrometric Th-230-U-234-U-238 dating of the Devils Hole calcite vein: Science, v. 258, p. 284-287, doi: 10.1126/science.258.5080.284. Winograd, I.J., Coplen, T.B., Landwehr, J.M., Riggs, A.C., Ludwig, K.R., Szabo, B.J., Kolesar, P.T., and Revesz, K.M., 1992, Continuous 500,000-year climate record from vein calcite in Devils Hole, Nevada: Science, v. 258, p. 255-260, doi: 10.1126/science.258.5080.255. Coplen, T.B., Winograd, I.J., Landwehr, J.M., and Riggs, A.C., 1994, 500,000-year stable carbon isotope record from Devils Hole, Nevada: Science, v. 263, p. 361-365, doi: 10.1126/science.263.5145.361. Szabo, B.J., Kolesar, P.T., Riggs, A.C., Winograd, I.J., and Ludwig, K.R., 1994, Paleoclimatic inferences from a 120,000-year calcite record of water-table fluctuation in Browns Room of

In support of paleoclimatology investigations, samples of mammillary calcite, calcitic folia, and flowstone were collected by the U.S. Geological Survey in Devils Hole and Devils Hole Cave 2, Nevada, between 1983 and 1996. These samples came from about 60 m below to 9 m above the modern water table in these caverns. To determine δ18O and δ13C time series spanning the interval 567.7–4.5 ka, more than a thousand samples were milled and analyzed for their δ18O and δ13C values. To determine time-series ages, more than a hundred samples were analyzed using uranium-series dating. Many of these measurement results have not been published. Herein, we provide previously unpublished δ13C and δ18O values, and we provide unpublished background data for selected uranium-series ages.

For more than a half million years, dense vein calcite has been precipitating in Devils Hole, located about 115 km northwest of Las Vegas, Nevada. This process also occurs in Devils Hole Cave 2, which is hydrologically connected and situated about 200 meters north of the original Devils Hole cave. Calcite has been precipitating in this natural laboratory in oxygen isotopic equilibrium at constant temperature to a depth of at least 140 meters. This vein calcite, also called mammillary calcite because of its morphology, is suitable for high-accuracy uranium-series dating. Continuously submerged calcite contains an unbroken record of the sequential variation of the oxygen isotopic composition of water recharging this well-mixed environment. A record of stable oxygen isotopes in the continuously submerged calcite provides climate variations spanning 563 thousand years. This record displays warm and cold climate cycles. Paleoclimate modelers use the Devils Hole oxygen-isotope record to validate climate models. Model prediction is particularly relevant for the parched southwestern United States. This high-accuracy oxygen-isotope time series was used to correct published uranium-series ages of non-continuously formed calcite in two cores (see Table S1 and Figure S1), cyclically exposed by water-table decline during glacial-interglacial transitions. This method relies on the premise that the oxygen isotopic compositions of coevally precipitated calcite are identical, allowing matching calcite oxygen isotopic composition values to establish formation ages. Uranium-series ages (based on matching oxygen-isotope values) differ by thousands of years because of mobility of uranium in samples from cores collected at or above the modern water table (Table S1). As a part of this project, samples of bat guano and soil samples were analyzed for uranium concentration (see Table S2 and Figure S2). The mean uranium-238 concentration of original formation uranium within continuously submerged vein calcite (termed primary uranium) can be estimated from uranium-238 concentrations of vein calcite within samples collected from cores deeper than 20 meters below the modern water table. The mean uranium-238 mass fraction within these deep samples (Table S3) is 456 ± 100 nanograms per gram (2 sigma uncertainty, n = 45). Uranium added to calcite samples after their formation is termed secondary uranium. Secondary uranium in a calcite sample can decrease the apparent uranium-series age of that sample if its secondary uranium concentration is not accounted for. The estimated mass fraction of secondary uranium-238 within 46 samples from nine cores collected at or above the modern water table having uranium-series ages less than 296,000 years ranges from 30 to 37,046 nanograms per gram (Table S4). The estimated secondary uranium-238 concentrations within 14 samples from six cores having uranium-series ages greater than 296,000 years is shown in Table S5. Nineteen samples from eight cores (Table S6) have uranium-238 concentrations substantially lower than that of primary uranium (Table S3). Based on an evaluation of oxygen isotopic compositions of samples from core DH2-D (Table S1), the uranium-series ages between approximately 140 and 120 thousand years ago need to be increased by between 4 and 8 kyr as shown in Figure S3. Based on a comparison of oxygen isotopic compositions of folia, flowstone, and calcite from Brown’s Room, a subaerial room in Devils Hole, with those of cores DHC2-8 or DH-2 (Table S1), many formation ages of Brown’s Room samples are as much as 11,600 years too young (Table S7 and Figure S4). Figure S5 is a cross-sectional sketch of Devils Hole Cave 2 showing the estimated minimum zone of cessation of precipitation of vein (mammillary) calcite since approximately 18 to 20 thousand years ago.

This archived Paleoclimatology Study is available from the NOAA National Centers for Environmental Information (NCEI), under the World Data Service (WDS) for Paleoclimatology. The associated NCEI study type is Cave. The data include parameters of speleothems with a geographic location of Nevada, United States Of America. The time period coverage is from 567700 to 59800 in calendar years before present (BP). See metadata information for parameter and study location details. Please cite this study when using the data.

This archived Paleoclimatology Study is available from the NOAA National Centers for Environmental Information (NCEI), under the World Data Service (WDS) for Paleoclimatology. The associated NCEI study type is Cave. The data include parameters of speleothems with a geographic location of Nevada, United States Of America. The time period coverage is from 567700 to 4500 in calendar years before present (BP). See metadata information for parameter and study location details. Please cite this study when using the data.

This data release contains whole-rock major, minor, and trace element geochemical data for carbonatite samples from the Mountain Pass rare earth element (REE) deposit located in southeastern California. The Mountain Pass deposit is the largest REE deposit in the United States and in 2021, produced 43,000 metric tons (expressed as rare-earth-oxide equivalent; U.S. Geological Survey, 2022). Samples include a suite of outcrop samples (2018) and a suite of composite samples (2019). Data are reported in comma-separated values (CSV) files. All column headings and abbreviations are explained in the metadata. Reference U.S. Geological Survey, 2022, Mineral commodity summaries 2022: U.S. Geological Survey, 202 p., https://doi.org/10.3133/mcs2022.

This data release contains whole-rock major, minor, and trace element geochemical data for carbonatite samples from the Mountain Pass rare earth element (REE) deposit located in southeastern California. The Mountain Pass deposit is the largest REE deposit in the United States and in 2021, produced 43,000 metric tons (expressed as rare-earth-oxide equivalent; U.S. Geological Survey, 2022). Samples include a suite of outcrop samples (2018) and a suite of composite samples (2019). Data are reported in comma-separated values (CSV) files. All column headings and abbreviations are explained in the metadata. Reference U.S. Geological Survey, 2022, Mineral commodity summaries 2022: U.S. Geological Survey, 202 p., https://doi.org/10.3133/mcs2022.

This archived Paleoclimatology Study is available from the NOAA National Centers for Environmental Information (NCEI), under the World Data Service (WDS) for Paleoclimatology. The associated NCEI study type is Cave. The data include parameters of speleothems with a geographic location of California, United States Of America. The time period coverage is from Unavailable begin date to Unavailable end date in calendar years before present (BP). See metadata information for parameter and study location details. Please cite this study when using the data.

This archived Paleoclimatology Study is available from the NOAA National Centers for Environmental Information (NCEI), under the World Data Service (WDS) for Paleoclimatology. The associated NCEI study type is Cave. The data include parameters of speleothems with a geographic location of California, United States Of America. The time period coverage is from 19390 to 8702 in calendar years before present (BP). See metadata information for parameter and study location details. Please cite this study when using the data.

This portion of the data release presents stable carbon isotopes of rock samples collected from Von Damm vent field, Mid-Cayman Rise, in the Caribbean Sea. These data were collected in 2020 (USGS Field Activity 2020-602-FA).