Devils Hole, Nevada--A Primer

This fact sheet summarizes the multifaceted research of the U.S. Geological Survey—published in diverse outlets—that focuses on the subaqueous cavern Devils Hole in Nevada.

What is Devils Hole?

Devils Hole is a subaqueous cavern in south-central Nevada within a geographically detached unit of Death Valley National Park (fig. 1). The cavern is tectonic in origin and has developed in Cambrian carbonate rocks bordering the Ash Meadows oasis (Carr, 1988). The open fault zone comprising the cave extends to a depth of at least 130 meters below the water table, which is about 15 meters below land surface (Riggs and others, 1994). The primary source of groundwater flowing through Devils Hole, and discharging from the major springs within the oasis, is precipitation on the Spring Mountains to the east of the cavern. The Spring Mountains are the highest mountain range in southern Nevada (altitude 3,630 meters) (Winograd and Thordarson, 1975; Winograd and others, 1998).

Why is Devils Hole of interest to paleoclimatologists?

The importance of Devils Hole to paleoclimatologists is twofold. Below the water table, the near-vertical walls of Devils Hole are coated with up to 40 centimeters of vein calcite that precipitated from groundwater moving through the cavern (fig. 2). The calcite can be accurately and precisely dated with radiometric methods, such that the depth-varying sequences of oxygen and carbon stable isotopes in the calcite provide a record of climatic variations spanning more than 500,000 years (Winograd and others, 1988, 1992, 2006). Additionally, subhorizontal cave deposits, called folia, record variations of the water table during the past 120,000 years (Szabo and others, 1994).

How was the isotopic record from the Devils Hole vein calcite dated?

Since 1992, vein calcite samples have been uranium-series dated using thermal ionization mass spectrometric (TIMS) methodology (Ludwig and others, 1992). In 1997, the Devils Hole thorium-230 ages were independently confirmed by non-U.S. Geological Survey (USGS) investigators using protactinium-231 (Edwards and others, 1997).

What paleoclimate phenomena are recorded by the Devils Hole stable isotopic time series?

The Devils Hole oxygen-18 (δO) time series (fig. 3) is primarily a proxy indicator of paleotemperatures. Unlike oxygen isotopes in deep-sea cores, it is not a record of past global ice accumulation in terrestrial systems. Rather, the time series appears to correspond, both in timing and relative magnitude, to variations in paleo-sea-surface temperature (SST) recorded in Pacific Ocean sediments off the west coast of North America, from Oregon to California, and as far south as the equatorial eastern Pacific (fig. 4) (Winograd and others, 1996, 1997, 2006; Lea and others, 2000; Herbert and others, 2001; Winograd, 2002). The Devils Hole δO record is also highly correlated with major variations in paleotemperatures recorded in the Vostok ice core from the East Antarctic Plateau (Landwehr and Winograd, 2001; Landwehr, 2002). The Devils Hole carbon-13 (δC) time series is thought to reflect changes in global variations in the ratio of stable carbon isotopes of atmospheric carbon dioxide (CO2) and (or) changes in the density of vegetation in the groundwater-recharge areas tributary to Devils Hole (Coplen and others, 1994).

Figure 4 (right). The Devils Hole δO (in blue) and sea-surface temperature (in red) time series from marine cores TR163-19 retrieved in the east equatorial Pacific at 2°N and 91°W (Lea and others, 2000) and ODP1020 retrieved off the Oregon-California border at 41°N and 126°W (Herbert and others, 2001). The linear correlation coefficient “r” between records is shown for the period from 4,500 to 360,000 years before present (Winograd and others, 2006).

Where can one find the isotopic records?

The δO and δC time series from ~560,000 to 60,000 years before present are provided in USGS Open-File Report 97–792 [http://pubs.usgs.gov/of/1997/ofr97-792/] (Landwehr and others, 1997). The δO record for Devils Hole was

What contributions has Devils Hole research made to the fields of paleoclimatology, paleohydrology, and geochemistry?

Publication of the half-million-year-long Devils Hole δO time series in 1992 initiated a decades-long discussion regarding the capability of the Milankovitch hypothesis (also referred to as orbital or astronomical theory) to predict the onset and duration of Pleistocene ice ages, a discussion that continues to extended into the mid-Holocene (up to ~4,500 years before present) and is provided in USGS Open-File Report 2011–1082 [http://pubs.usgs.gov/of/2011/1082/] (Landwehr and others, 2011).

this day (Wunsch, 2004; Henderson and others, 2006; Lourens and others, 2010). The radiometrically dated Devils Hole time series indicates an atmospheric warming beginning more than 10,000 years earlier than the timing of the penultimate major deglaciation (also referred to as Termination II) as predicted on the basis of the Milankovitch hypothesis. This has been considered to be a direct challenge to the validity of orbital theory (Broecker, 1992; Karner and Muller, 2000). This challenge was dismissed by some on the grounds that if the question of early warming was ignored, the Devils Hole records might be interpreted as supporting the Milankovitch hypothesis (Emiliani, 1993; Imbrie and others, 1993) but contradicted by others who claimed that early warming, though real, reflected only regional, not global, climate (Herbert and others, 2001). However, the original challenge posed by the early warming recorded in the Devils Hole δO time series continues: it has been reinforced by a variety of studies, not only of interhemispheric paleo-SST warming, but also of sea-level high stands (a direct proxy for global ice volume conditions) that have been directly dated as occurring thousands of years prior to orbitally predicted global deglaciations (Winograd and Landwehr, 1993; Landwehr and others, 1994; Henderson and Slowey, 2000; Henderson and others, 2001, 2006; Gallup and others, 2002; Muhs and others, 2002; Winograd, 2002; Winograd and others, 2006).

Prior to publication of the Devils Hole δO time series, the duration of Pleistocene interglacial intervals was thought to be on the order of 12,000 years, as determined from orbitally tuned chronologies based on marine sediment records (Imbrie and others, 1984). However, an examination of the Devils Hole record published in 1997 revealed that the warmest portion alone of the past four interglaciations lasted on the order of 10,000 to 15,000 years, whereas the entire duration of the warm intervals (interglacials) persisted in excess of 20,000 years, a finding supported by both Antarctic ice core data and sea level data (Winograd and others, 1997; Muhs and others, 2002). An additional continuing challenge to the Milankovitch hypothesis has been the occurrence of a high-intensity and long-duration interglacial from ~420,000 to ~395,000 years before present at a time of minimal variation in insolation, as recorded not only in marine isotopic records but also in the Devils Hole record (Winograd and others, 1992). The high correlation between the Devils Hole record and the ice core record at Vostok on the East Antarctic Plateau indicates a consistent interhemispheric timing of Pleistocene ice ages, which also is not consistent with the Milankovitch hypothesis (Landwehr and Winograd, 2001).

More recent work has corroborated these insights derived from Devils Hole, and it is widely acknowledged today that astronomical forcing alone cannot explain the duration, intensity, or diversity of the past four interglacials. More independently dated proxy records from both hemispheres would be

What does Devils Hole reveal about how long we can expect the present interglaciation to last?

No one knows for sure how long the present interglacial will last. Any estimate depends on several factors: the paleoclimatic archive and proxy record(s) utilized; the degree to which these records reflect global conditions; the theory invoked; and current potential climatic influences, such as anthropogenically generated greenhouse gases. The Devils Hole δO record indicates that the last four interglaciations each lasted over ~20,000 years, with the warmest portion being a relatively stable period of 10,000 to 15,000 years duration (Winograd and others, 1997). The most recent portion of the Devils Hole record suggests—as required to achieve such an understanding (Tzedakis and others, 2009). In addition, it is now widely acknowledged that variations in atmospheric greenhouse gases, notably CO2, have played a major role in the glacial-interglacial climatic shifts of the Pleistocene, though major questions persist regarding the origin of the “ice ages” (Raymo and Huybers, 2008).

In addition to the near-vertical vein calcites that precipitated from groundwater below the water table and today line the walls of the steeply dipping open fault, Devils Hole cave also contains subhorizontal wall deposits, called folia, that mark the stands of the paleo-water table in the cavern (fig. 2) (Szabo and others, 1994; Kolesar and Riggs, 2004). The folia are porous deposits that owe their origin to outgassing at the water table of CO2 from the slightly supersaturated groundwater flowing through Devils Hole (Plummer and others, 2000). In Brown’s Room, a remote portion of Devils Hole cave, the folia were sampled up to about 9 meters above the modern water table. The folia visible in the upper fifth of figure 2 indicate that the water table was once about a meter lower than its modern level. Uranium-series dating of these folia has enabled the development of a 120,000-year hydrograph of water-table fluctuation in the cavern, which indicates a prominent decline during the past 20,000 years (Szabo and others, 1994).

An unexpected consequence of the ability to carry out precise uranium-series dating of the Devils Hole cave calcite has been a renewed interest in other cave carbonate deposits, notably speleothems and flowstones (Kolesar, 2004), as archives of Quaternary paleoclimate. Speleothems now comprise a major archive of continental paleoclimatic data (Ludwig and others, 1992; Quade, 2004; Lachniet, 2009).

A comparison of the δO measured in the vein calcite relative to that in Devils Hole groundwater has led to a new and significantly different estimate of the oxygen isotopic fractionation between calcite and water in a natural (non-laboratory) environment. This important contribution to aqueous geochemistry was possible because the physical and chemical constancy of environmental conditions at Devils Hole at depths greater than several meters below the water table—a constancy believed to have prevailed for at least 10 millennia—permits measurement of this fractionation in an environment at or near thermodynamic equilibrium (Coplen, 2007). Additionally, the high purity of the dense vein calcite allowed the development and testing of a new method with which to determine the δC and δO isotopic composition of CaCO3 using smaller mass than previously possible (Revesz and Landwehr, 2002).

do SST records off California—that the warmest portion of the current interglaciation began by 17,000 years before present (Winograd and others, 2006). From these data one might infer that in the absence of any mitigating conditions, such as anthropogenically induced climate warming, the onset of a period of global cooling is imminent or even overdue on a geologic time scale (Ruddiman, 2007). However, some researchers have suggested that the current interglaciation might continue for tens of thousands of years (Berger and Loutre, 2002).

What are some practical applications of the Devils Hole findings?

In addition to providing information about the possible duration of our present interglacial climate (discussed above), research in Devils Hole has been a source of valuable information for water managers. Devils Hole cave provides hydrologists with direct access for making hydraulic measurements and collecting chemical samples of the regional carbonate-rock aquifer underlying much of south-central Nevada and which supplies the groundwater that is discharging within the Ash Meadows oasis. Meaningful estimates of the sustainable use of this aquifer hinge on knowing the age of the groundwater. Estimates of the groundwater age inferred from carbon-14 dating of dissolved inorganic carbon in the groundwater have yielded an age in the range of 13,000 to 25,000 years (Anderson,

Why is Devils Hole of interest to zoologists?

The endangered species of pupfish Cyprinodon diabolis is endemic to Devils Hole, with a habitat dependent on stable groundwater-table levels (Dudley and Larson, 1976). Concern for the protection of this unique species’ habitat provided the first test of the Endangered Species Act and resulted in the unanimous affirmative landmark decision by the U.S. Supreme Court in 1976 (Cappaert v. United States, 426 U.S. 128). This pupfish species has been studied by zoologists for decades,

References Cited

Anderson, K.W., 2002, Contribution of local recharge to high flux springs in Death Valley National Park, California-Nevada: Provo, Utah, Brigham Young University, M.S. thesis, 122 p.

Berger, A., and Loutre, M.F., 2002, An exceptionally long interglacial ahead?: Science, v. 297, p. 1287–1288.

Broecker, W.S., 1992, Upset for Milankovitch theory: Nature, v. 359, p. 779–780.

Carr, W.J., 1988, Geology of the Devils Hole area, Nevada: U.S. Geological Survey Open-File Report 87–560, 32 p. (Also available at http://pubs.usgs.gov/of/1987/0560/report.pdf.)

Coplen, T.B., 2007, Calibration of the calcite-water oxygen-isotope geothermometer at Devils Hole, Nevada, a natural laboratory: Geochimica et Cosmochimica Acta, v. 71, p. 3948–3957.

Coplen, T.B., Winograd, I.J., Landwehr, J.M., and Riggs, A.C., 1994, 500,000-year stable carbon isotopic record from Devils Hole, Nevada: Science, v. 263, p. 361–365.

Dudley, W.W., Jr., and Larson, J.D., 1976, Effect of irrigation pumping on desert pupfish habitats in Ash Meadows, Nye County, Nevada: U.S. Geological Survey Professional Paper 927, 52 p. (Also available at http://pubs.usgs.gov/pp/0927/report.pdf.)

2002), whereas carbon-14 dating of dissolved organic carbon has yielded ages on the order of 3,000 to 7,000 years (Thomas, 1996; Morse, 2002). However, several lines of evidence derived from Devils Hole indicate a groundwater age of 2,000 years or less (as discussed in appendix A in Winograd and others, 2006). The evaluation of Yucca Mountain, which is about 45 kilometers north-northwest of Devils Hole, for the geologic disposal of spent nuclear fuel has required estimation of past and future climates over time frames of hundreds of thousands of years. The paleoclimatologic and paleohydrologic information gleaned from Devils Hole has provided the foundation for such estimates (Forester and others, 1999; Sharpe, 2007; Paces and others, 2010).

not only because of its unusual habitat, but also because of speciation-process debates concerning the length of its isolation from other members of its genus (Riggs and Deacon, 2004).

Estimates of the length of its isolation range from tens of thousands of years (Riggs, 1991) to perhaps hundreds of thousands of years (Winograd, 1991; based on data in Winograd and Szabo, 1988).

Edwards, R.L., Cheng, H., Murrell, M.T., and Goldstein, S.J., 1997, Protactinium-231 dating of carbonates by thermal ionization mass spectrometry—Implications for Quaternary climate change: Science, v. 276, p. 782–786.

Emiliani, Cesare, 1993, Milankovitch theory verified: Nature, v. 364, p. 583–584.

Forester, R.M., Bradbury, J.P., Carter, C., Elvidge-Tuma, A.B., Hemphill, M.L., Lundstrom, S.C., Mahan, S.A., Marshall, B.D., Naymark, L.A., Paces, J.B., Sharpe, S.E., Whelan, J.F., and Wigand, P.E., 1999, The climatic and hydrologic history of southern Nevada during the late Quaternary: U.S. Geological Survey Open-File Report 98–635, 63 p. (Also available at http://pubs.usgs.gov/of/1998/0635/report.pdf.)

Gallup, C.D., Cheng, H., Taylor, F.W., and Edwards, R.L., 2002, Direct determination of the timing of sea level change during Termination II: Science, v. 295, p. 310–313.

Henderson, G.M., Robinson, L.F., Cox, Katharine, Thomas, A.L., 2006, Recognition of non-Milankovitch sea-level highstands at 185 and 343 thousand years ago from U-Th dating of Bahamas sediment: Quaternary Science Reviews, v. 25, p. 3346–3358.

Henderson, G.M., and Slowey, N.C., 2000, Evidence from U-Th dating against Northern Hemisphere forcing of the penultimate deglaciation: Nature, v. 404, p. 61–66.

Henderson, G.M., Slowey, N.C., and Fleisher, M.Q., 2001, U-Th dating of carbonate platform and slope sediments: Geochimica et Cosmochimica Acta, v. 65, no. 16, p. 2757–2770.

Herbert, T.D., Schuffert, J.D., Andreasen, D., Heusser, L., Lyle, M., Mix, A., Ravelo, A.C., Stott, L.D., and Herguera, J.C., 2001, Collapse of the California current during glacial maxima linked to climate change on land: Science, v. 293, p. 71–76.

Imbrie, J., Hays, J.D., Martinson, D.G., McIntyre, A., Mix, A.C., Morley, J.J., Pisias, N.G., Prell, W.L., and Shackleton, N.J., 1984, The orbital theory of Pleistocene climate—Support from a revised chronology of the marine δO record, in Berger, A., and others, eds., Milankovitch and climate: Dordrecht, D. Reidel Publishing Company, p. 269–305.

Imbrie, J., Mix, A.C., and Martinson, D.G., 1993, Milankovitch theory viewed from Devils Hole: Nature, v. 363, p. 531–533.

Karner, D.B., and Muller, R.A., 2000, A causality problem for Milankovitch: Science, v. 288, p. 2143–2144.

Kolesar, P.T., 2004, New Devils Hole paleoclimatic record— Preliminary appraisal of a new paleoclimate record from Devils Hole, Nevada: Northeastern Geology and Environmental Sciences, v. 26, nos. 1 and 2, p. 49–56.

Kolesar, P.T., and Riggs, A.C., 2004, Influence of depositional environment on Devils Hole calcite morphology and petrology, in Sasowsky, I.D., and Mylroie, John, eds., Studies of cave sediments—Physical and chemical records of paleoclimate: New York, Kluwer Academic/Plenum Publishers, p. 227–241.

Lachniet, M.S., 2009, Climatic and environmental controls on speleothem oxygen-isotope values: Quaternary Science Reviews, v. 28, p. 412–432.

Landwehr, J.M., 2002, Ice core depth-age relation for Vostok D and Dome Fuji δO records based on the Devils Hole paleotemperature chronology: U.S. Geological Survey Open-File Report 02–266, 53 p. (Also available at http://pubs.usgs.gov/of/2002/ofr02-266/.)

Landwehr, J.M., Coplen T.B., Ludwig, K.R., Winograd, I.J., and Riggs, A.C., 1997, Data for Devils Hole core DH–11: U.S. Geological Survey Open-File Report 97–792, 8 p. (Also available at http://pubs.usgs.gov/of/1997/ofr97-792/.)

Landwehr, J.M., Sharp, W.D., Coplen, T.B., Ludwig, K.R., and Winograd, I.J., 2011, The chronology for the δO record from Devils Hole, Nevada, extended into the mid-Holocene: U.S. Geological Survey Open-File Report 2011–1082, 5 p. (Also available at http://pubs.usgs.gov/of/2011/1082/.)

Landwehr, J.M., Winograd, I.J., and Coplen, T.B., 1994, No verification for Milankovitch: Nature, v. 368, p. 594.

Landwehr, J.M., and Winograd, I.J., 2001, Dating the Vostok ice core record by importing the Devils Hole chronology: Journal of Geophysical Research - Atmospheres, v. 106, No. D23, p. 31853–31862.

Lea, D.W., Pak, D.K., and Spero, H.J., 2000, Climate impact of late Quaternary equatorial Pacific sea surface temperature variations: Science, v. 289, p. 1719–1724.

Lourens, L.J., Becker, J., Bintanja, R., Hilgen, F.J., Tuenter, E., van de Wal, R.S.W., and Ziegler, M., 2010, Linear and non-linear response of late Neogene glacial cycles to obliquity forcing and implications for the Milankovitch theory: Quaternary Science Reviews, v. 29, p. 352–365.

Ludwig, K.R., Simmons, K.R., Szabo, B.J., Winograd, I.J., Landwehr, J.M., Riggs, A.C., and Hoffman, R.J., 1992, Massspectrometric Th-U-U dating of the Devils Hole calcite vein: Science, v. 258, no. 5080, p. 284–287.

Morse, B.S., 2002, Radiocarbon dating of groundwater using paleoclimate constraints and dissolved organic carbon in southern Great Basin, Nevada and California: Reno, University of Nevada, M.S. thesis, 63 p.

Muhs, D.R., Simmons, K.R., and Steinke, Bree, 2002, Timing and warmth of the last interglacial period—New U-series evidence from Hawaii and Bermuda and a new fossil compilation for North America: Quaternary Science Reviews, v. 21, p. 1355–1383.

Paces, J.B., Neymark, L.A., Whelan, J.F., Wooden, J.L., Lund, S.P., and Marshal, B.D., 2010, Limited hydrologic response to Pleistocene climate change in deep vadose zones, Yucca Mountain, Nevada: Earth and Planetary Science Letters, v. 300, p. 287–298.

Plummer, L.N., Busenberg, E., and Riggs, A.C., 2000, In-situ growth of calcite at Devils Hole, Nevada—Comparison of field and laboratory rates to a 500,000 year record of nearequilibrium calcite growth: Aquatic Geochemistry, v. 6, no. 2, p. 257–274.

Quade, Jay, 2004, Isotopic records from ground-water and cave speleothem calcite in North America, in Gillespie, A.R., Porter, S.C., and Atwater, B.F., eds., The Quaternary Period in the United States: Elsevier, p. 205–220.

Raymo, M.E., and Huybers, Peter, 2008, Unlocking the mysteries of the ice ages: Nature v. 451, p. 284–285.

Revesz, K.M., and Landwehr, J.M., 2002, δC and δO isotopic composition of CaCO3 measured by continuous flow isotope ratio mass spectrometry—Statistical evaluation and verification by application to Devils Hole core DH-11 calcite: Rapid Communications in Mass Spectrometry, v. 16, p. 2102–2114.

Riggs, A.C., 1991, Geohydrologic evidence for the development of Devils Hole, southern Nevada, as an aquatic environment: Proceedings of the Desert Fishes Council XX, p. 47–48.

Riggs, A.C., Carr, W.J., Kolesar, P.T., and Hoffman, R.J., 1994, Tectonic speleogenesis of Devils Hole, Nevada, and implications for hydrogeology and the development of long, continuous paleoenvironmental records: Quaternary Research, v. 42, no. 3, p. 241–254.

Riggs, A.C., and Deacon, J.E., 2004, Connectivity in desert aquatic ecosystems—The Devils Hole story, in Sada, D.W., and Sharpe, S.E., eds., Spring-fed wetlands—Important scientific and cultural resources of the intermountain region [Proceedings], Las Vegas, Nevada, May 7–9, 2002: Desert Research Institute DHS Publication No. 41210, p. 1–38.

Ruddiman, W.F., 2007, The early anthropogenic hypothesis— Challenges and responses: Reviews of Geophysics, v. 45, RG4001, 37 p.

Sharpe, S.E., 2007, Using modern through mid-Pleistocene climate proxy data to bound future variations in infiltration at Yucca Mountain, Nevada, in Stuckless, J.S., and Levich, R.A., eds., The geology and climatology of Yucca Mountain and vicinity, southern Nevada and California: Geological Society of America Memoirs 199, p. 155–205.

Szabo, B.J., Kolesar, P.T., Riggs, A.C., Winograd, I.J., and Ludwig, K.R., 1994, Paleoclimatic inferences from a 120,000-yr calcite record of water-table fluctuation in Browns Room of Devils Hole, Nevada: Quaternary Research, v. 41, p. 59–69.

Thomas, J.M., 1996, Geochemical and isotopic interpretations of groundwater flow, geochemical processes, and the age dating of groundwater in carbonate-rock aquifers of the southern Basin and Range: Reno, University of Nevada, Ph.D. dissertation, 135 p.

Tzedakis, P.C., Raynaud, D., McManus, J.F., Berger, A., Brovkin, V., and Kiefer, T., 2009, Interglacial diversity: Nature Geoscience, v. 2, p. 751–755.

U.S. Supreme Court, 1976, Cappaert v. United States, 426 U.S. 128 (1976) No. 74–1107.

Winograd, I.J., 1991, Time of isolation of Cyprinodon diabolis in Devils Hole—Geologic evidence: Proceedings of the Desert Fishes Council, v. XX, p. 49–50.

Winograd, I.J., 2002, The California current, Devils Hole, and Pleistocene climate: Science, v. 296, p. 7. (Full text available at http://www.sciencemag.org/content/296/5565/7a.)

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, no. 5080, p. 255–260.

For more information, contact:

Jurate M. Landwehr U.S. Geological Survey, 431 National Center 12201 Sunrise Valley Drive Reston, VA 20192 E-mail: jmlandwe@usgs.gov Winograd, I.J., Coplen, T.B., Ludwig, K.R., Landwehr, J.M., and Riggs, A.C., 1996, High resolution δO record from Devils Hole, Nevada, for the period 80 to 19 ka: EOS, v. 77, no. 17, p. S169.

Winograd, I.J. and Landwehr, J.M., 1993, A response to “Milankovitch Theory viewed from Devils Hole” by J. Imbrie, A.C. Mix, and D.G. Martinson: U.S. Geological Survey Open-File Report 93–357, 9 p. (Also available at http://pubs.usgs.gov/of/1993/0357/report.pdf.)

Winograd, I.J., Landwehr, J.M., Coplen, T.B., Sharp, W.D., Riggs, A.C., Ludwig, K.R., and Kolesar, P.T., 2006, Devils Hole, Nevada, δO record extended to the mid-Holocene: Quaternary Research, v. 66, no. 2, p. 202–212.

Winograd, I.J., Landwehr, J.M., Ludwig, K.R., Coplen, T.B., and Riggs, A.C, 1997, Duration and structure of the past four interglaciations: Quaternary Research, v. 48, no. 2, p. 141–154.

Winograd, I.J., Riggs, A.C., and Coplen, T.B., 1998, The relative contributions of summer and cool-season precipitation to groundwater recharge, Spring Mountains, Nevada, USA: Hydrogeology Journal, v. 6, no. 1, p. 77–93.

Winograd, I.J., and Szabo, B.J., 1988, Water-table decline in the south-central Great Basin during the Quaternary—Implications for toxic waste disposal, in Carr, M.D., and Yount, J.C., eds., Geologic and hydrologic investigations of a potential nuclear waste disposal site at Yucca Mountain, southern Nevada: U.S. Geological Survey Bulletin 1790, p. 147–152. (Also available at http://pubs.usgs.gov/bul/1790/report.pdf.)

Winograd, I.J., Coplen T.B., Szabo, B.J., and Riggs, A.C., 1988, A 250,000-year climate record from Great Basin vein calcite—Implications for Milankovitch theory: Science, v. 242, no. 4883, p. 1275–1280.

Winograd, I.J., and Thordarson, William, 1975, Hydrogeologic and hydrochemical framework, south-central Great Basin, Nevada–California, with special reference to the Nevada Test Site: U.S. Geological Survey Professional Paper 712–C, 126 p. (Also available at http://pubs.usgs.gov/pp/0712c/report.pdf.)

Wunsch, Carl, 2004, Quantitative estimate of the Milankovitchforced contribution to observed Quaternary climate change: Quaternary Science Reviews, v. 23, p. 1001–1012.

Isaac J. Winograd U.S. Geological Survey, 432 National Center 12201 Sunrise Valley Drive Reston, VA 20192 E-mail: ijwinogr@usgs.gov

Where this page came from

This page was imported from U.S. Geological Survey. Published by the U.S. Geological Survey and, as a work of the United States government, in the public domain.

Nobody has written it yet — it is the source material at a new address, which is why search engines are asked to skip it and why no one earns from it. It is up for grabs: take it on, and it is yours to rewrite and to earn from.