Paleohydrology of Desert Wetlands

In southern Nevada, buff-colored deposits sit against the backdrop of Gass Peak and the Las Vegas Range just outside the city limits of Las Vegas. Once thought to be remnants of a large lake, the deposits actually record the presence of extensive wetlands that acted as watering holes to an array of Pleistocene megafauna, including mammoth, sloth, camel, horse, bison, and even lions and sabre-toothed cats. The deposits also hold valuable clues to understanding how fragile desert ecosystems responded to climate change in the past. This area has been recently designated as Tule Springs Fossil Beds National Monument. Photo courtesy Eric Scott, San Bernardino County Museum.
In southern Nevada, buff-colored deposits sit against the backdrop of Gass Peak and the Las Vegas Range just outside the city limits of Las Vegas. Once thought to be remnants of a large lake, the deposits actually record the presence of extensive wetlands that acted as watering holes to an array of Pleistocene megafauna, including mammoth, sloth, camel, horse, bison, and even lions and sabre-toothed cats. The deposits also hold valuable clues to understanding how fragile desert ecosystems responded to climate change in the past. This area has been recently designated as Tule Springs Fossil Beds National Monument. Photo courtesy Eric Scott, San Bernardino County Museum.

Desert wetlands are critical, groundwater dependent ecosystems that support endemic flora and fauna in a variety of hydrologic settings, including seeps, springs, marshes, wet meadows, outflow streams, ponds, and spring pools. Over time, eolian, alluvial, and fluvial sediments become trapped in these settings by a combination of wet ground conditions and dense plant cover. The result is a unique combination of clastic sediments, chemical precipitates, and organic matter that is preserved in the geologic record as ground-water discharge (GWD) deposits. GWD deposits contain information on the timing and magnitude of past changes in water-table levels and, therefore, are a potential source of paleohydrologic and paleoclimatic information. Our research group at the U.S. Geological Survey is studying GWD deposits at a number of sites throughout the southern Great Basin and Mojave Deserts in an effort to determine how small desert watersheds responded to past episodes of abrupt climate change. Recent results from the Las Vegas Valley (southern Nevada, USA) and elsewhere show that GWD deposits can be used to reconstruct paleohydrologic conditions at millennial to submillenial timescales, and illustrate the potential vulnerability of these fragile ecosystems to future anthropogenic warming.

Why is this research important?

Springs and desert wetlands are home to a number of threatened and endangered species that rely on these ecosystems for water in an otherwise arid landscape. Springs and wetlands are extremely sensitive to climate change and, therefore, also serve as potential harbingers of future hydrologic conditions. Information obtained from geologic deposits associated with these ecosystems allow us to constrain the range of natural climate and hydrologic variability that has occurred in the past. They also provide valuable information for land management agencies, water resource managers, and other interested parties that must develop management plans and mitigation strategies for natural resources in the deserts of the southwestern U.S.

Project Lead:

Jeff Pigati

Project Team:

Kathleen Springer, Craig Manker, Jeff Honke, Harland Goldstein, Shannon Mahan

Project Website


19 publications matching the specified parameters were found.

Springer, K.B., Pigati, J.S. and Scott, E., 2017, Vertebrate paleontology, stratigraphy, and paleohydrology of Tule Springs Fossil Beds National Monument, Nevada (USA), Geology of the Intermountain West, v. 4, p. 55-98.
Available at: https://www.utahgeology.org/openjournal/index.php/GIW/article/view/13

Oaks Jr, R.Q., 2016, The Bear River's History and Diversion: Constraints, Unsolved Problems, and Implications for the Lake Bonneville Record, Lake Bonneville, A Scientific Update, v. 20, p. 28.

Pigati, J.S., Muhs, D.R. and McGeehin, J.P., 2016, On the importance of stratigraphic control for vertebrate fossil sites in Channel Islands National Park, California, USA: Examples from new Mammuthus finds on San Miguel Island, Quaternary International.
Available at: https://doi.org/10.1016/j.quaint.2016.07.015

Scott, E., Springer, K.B., 2016, First records of Canis dirus and Smilodon fatalis from the late Pleistocene Tule Springs Local Fauna, southern Nevada, PeerJ, v. 4, p. e2151.
Available at: https://doi.org/10.7717/peerj.2151

Pigati, J.S., 2015, Radiocarbon dating of terrestrial carbonates, in Rink, W.J., Thompson, J.W., Heaman, L.M., Jull, A.J.T., Paces, J.B., eds., Encyclopedia of Scientific Dating Methods: New York NY, Springer Publishing, p. 680-685.
Available at: http://dx.doi.org/10.1007/978-94-007-6304-3_152

Pigati, J.S., McGeehin, J.P., Muhs, D.R., Grimley, D.C., Nekola, J.C., 2015, Radiocarbon dating loess deposits in the Mississippi Valley using terrestrial gastropod shells (Polygyridae, Helicinidae, Discidae): Aeolian Research, v. 16, p. 25-33.
Available at: http://dx.doi.org/10.1016/j.aeolia.2014.10.005

Pigati, J.S., Miller, I.M., and Johnson, K.R., 2015, The Snowmastodon Project: Cutting-edge science on the blade of a bulldozer: GSA Today, v. 25, p. 58-59.
Available at: http://dx.doi.org/10.1130/GSATG240GW.1

Pigati, J.S., Springer, K.B., and Manker, C.R., 2015, Desert Wetlands–Archives of a Wetter Past: U.S. Geological Survey Fact Sheet 2015-3077.
Available at: https://pubs.er.usgs.gov/publication/fs20153077

Reheis, M.C., Miller, D.M., McGeehin, J.R., Redwine, J.P., Oviatt, C.G., and Bright, J., 2015, Di Rectly dated MIS 3 lake-level Record from Lake Manix, Mojave Desert, California, USA: Quaternary Research, v. 83, p. 187-203.
Available at: http://dx.doi.org/10.1016/j.yqres.2014.11.003

Springer, K.B., Manker, C.R., Pigati, J.S., 2015, Dynamic response of desert wetlands to abrupt climate change: Proceedings of the National Academy of Sciences USA, v. 112, p. 14522-14526.
Available at: http://dx.doi.org/10.1073/pnas.1513352112

Stutz, A.J., Shea, J.J., Rech, J.A., Pigati, J.S., Wilson, J., Belmaker, M., Albert, R.M., Arpin, T., Cabanes, D., Clark, J.L., Hartman, G., Hourani, F., White, C.E., Nilsson- Stutz, L., 2015, Early Upper Paleolithic chronology in the Levant: new ABOx-SC accelerator mass spectrometry results from the Mughr el-Hamamah Site, Jordan: Journal of Human Evolution, v. 85, p. 157-173.
Available at: http://dx.doi.org/10.1016/j.jhevol.2015.04.008

Pigati, J.S., Rech, J.A., Quade, J., and Bright, J., 2014, Desert wetlands in the geologic record: Earth-Science Reviews, v. 132, p. 67-81.

Reheis, M.C., Adams, K.D., Oviatt, C.G., and Bacon, S.N., 2014, Pluvial lakes in the Great Basin of the western United States - a view from the outcrop: Quaternary Science Reviews, v. 97, p. 33-57.

Reheis, M.C., Miller, D.M., McGeehin, J.P., Redwine, J.R., Oviatt, C.G., and Bright, J., 2014, Directly dated MIS 3 lake-level record from Lake Manix, Mojave Desert, California, USA: Quaternary Research, v. 83, no. 1, p. 187-203.

Pigati, J.S., McGeehin, J.P., Muhs, D.R., Bettis, E.A. III, 2013, Radiocarbon dating late Quaternary loess deposits using small terrestrial gastropods. Quaternary Science Reviews, v. 76, p. 114-128.

Rakovan, M.T., Rech, J.A., Pigati, J.S., Nekola, J.C., and Wiles, G.C., 2013, An evaluation of Mesodon and other large terrestrial gastropod shells for dating late Holocene and historic alluvium in the Midwestern USA: Geomorphology, v. 193, p. 47-56.

Pigati, J.S., Latorre, C., Rech, J.A., Betancourt, J.L., Martinez, K.E., Budahn, J.R., 2012, Accumulation of 'impact markers' in desert wetlands and implications for the Younger Dryas impact hypothesis: Proceedings of the National Academy of Sciences USA, v. 109, no. 19, p. 7208-7212.

Rech, J.A., Nekola, J.C., and Pigati, J.S., 2012, Radiocarbon ages of terrestrial gastropods extend the duration of ice-free conditions at the Two Creeks forest bed, Wisconsin, USA: Quaternary Research, v. 77, p. 289-292.

Reheis, M.C., Bright, J., Lund, S.P., Miller, D.M., Skipp, G., Fleck, R.J., 2012, A half-million-year record of paleoclimate from the Lake Manix Core, Mojave Desert, California: Palaeogeography, Palaeoclimatology, Palaeoecology, v. 365-366, p. 11-37.
Available at: http://www.sciencedirect.com/science/article/pii/S0031018212004981


Paleoclimate Variability of the American Southwest

The primary objective of this project is to determine how climate conditions in general, and precipitation in particular, have changed over time in the American Southwest. Landscapes and ecosystems in the American Southwest are sensitive to climate change and respond through variations in runoff, lake size, depth to groundwater, and eolian sand/dust movement. Annual and interannual precipitation varies geographically and temporally due to the influences of the El Nino-Southern Oscillation system and occasional intense "Pineapple Express" storms. We study lake, ground-water discharge, and eolian deposits and packrat middens as archives of environmental change in low- to mid-altitude desert basins to provide better definition of climate variability in this region. We also use several physical and chemical proxy methods to quantitatively reconstruct temperature and precipitation conditions at various sites during the late Quaternary. Current focus is on basins in the Mojave and Sonoran deserts.

Why is this research important?

Predicting precipitation, its potential range of variability, and effects on landscapes and biota is difficult. More precise and accurate records of paleoenvironmental conditions in the Desert Southwest during Pleistocene pluvial periods, wet-dry transitions, and extreme droughts during the Holocene, and correlation of these records with those from nearby marine cores, will constrain the range of expectable natural climate variability and its effects on landscapes and biota, and provide input to land-management agencies, water resource managers, and other groups to help plan mitigation strategies in response to a changing global climate.