Research | Paleolimnology & Paleoclimatology

In the US Great Basin

We have an active research program studying the history of lakes associated with the US Basin and Range Province. Much of the information we have obtained about this history is derived from scientific drilling campaigns, which have yielded long sediment cores from old lake deposits. Primary study areas for this work have been the Great Salt Lake/Lake Bonneville & Bear Lake, Utah, and Summer Lake, Oregon.

Great Salt Lake/Lake Bonneville & Bear Lake, Utah

We have studied drilling and seismic records of the Great Salt Lake (GSL) basin collected by AMOCO to interpret basin history, paleolimnology, and palynology over the last 10 million years (Davis and Moutoux, 1998; Kowalewska and Cohen, 1998; Davis, 2002). Using the dedicated Global Lakes Drilling system, the GLAD800, our colleagues at the USGS, the University of Minnesota's Limnological Research Center, and the UA have obtained a series of cores (the longest being over 120m) spanning the last ~270,000 years of pluvial lake history from the Great Salt Lake and Bear Lake (Dean et al., 2002; Balch, 2003 and in prep.). Neogene records of the basin indicate it was occupied by a series of extensive marshes over much of its history, linked with the Paleolake Idaho drainage to the north, with the GSL Basin as the terminus of the drainage system. Extensive lakes only began to evolve in the Quaternary. The GSL record is also notable for providing evidence of major cyclical crashes in lake level and salinity crises in the lake at the even/odd oxygen isotope stage boundaries, following several major lake high stands in the late parts of OIS 6, 4 and 2.

Balch, D., 2003 and in prep. "Quaternary ostracode paleoecology and its link to climate change in the Bonneville Basin: A detailed study of the GLAD800 core GSL00-4, Great Salt Lake, Utah." MS Thesis, Univ. of Arizona.

Davis, O.K., 2002. "Late Neogene environmental history of the Northern Bonneville Basin: A review of palynological studies." In Herschler, R., Madsen, D.B. and Currey, D.R. (eds.) "Great Basin Aquatic Systems History Smithsonian Contributions to Earth." Sciences 33:295-308.

Davis, O.K. and Moutoux, T., 1998. "Tertiary and Quaternary vegetation history of the Great Salt Lake. Jour." Paleolimnology 19:417-427.

Dean, W., Rosenbaum, J., Haskell, B., Kelts, K., Schnurrenberger, D., Valero-Garces, B., Cohen, A.S., Davis, O.K., Dinter, D., and Nielson, D., 2002. "Progress in global lake drilling holds potential for global change research." EOS 83:85, 90-91.

Kowalewska, A. and Cohen, A.S., 1998. "Reconstruction of paleoenvironments of the Great Salt Lake Basin during the late Cenozoic." Jour. Paleolimnology 20:381-407.

Summer Lake, Oregon

At Summer Lake, we have obtained a 250,000 year record of climate change in the northwestern Great Basin, where it meets the Cascade Mountains (Palacios-Fest et al., 1993; Cohen et al., 2000 and Negrini et al, 2000). A combination of sedimentologic, paleoecologic, environmental magnetic, and geochemical data indicates fluctuations in the levels and salinity of Summer Lake and its predecessor, Lake Chewaucan, in synchrony with the marine oxygen isotope record of global glacial advances. The Summer Lake record is notable for providing clear evidence of the power of using minor element ratios in ostracode crustacean shells for the quantitative inference of paleolimnological parameters, especially the use of Mg/Ca ratios to infer paleotemperatures.

Cohen, A.S., Palacios-Fest, M. R., Negrini, R., Wigand, P. and Erbes, D., 2000. "A paleoclimate record for the past 250,000 years from Summer Lake, Oregon, USA II Sedimentology, paleontology and geochemistry." Jour. Paleolimnology 24:151-182.

Negrini, R.M., Erbes, D., Faber, K., Herrera, A.M., Roberts, A.P., Cohen, A.S., Wigand, P.E., and Foit, F.F., 2000. "A paleoclimate record for the past 250,000 years from Summer Lake, Oregon, USA I Chronology and magnetic proxies for lake level." Jour. Paleolimnology 24:125-149.

Palacios-Fest, M.R., Cohen, A.S., Ruiz, J. and Blank, B., 1993. "Comparative paleoclimatic interpretations from nonmarine ostracodes using faunal assemblages, trace element shell chemistry and stable isotope data." In Swart, P.K. et al. (eds.) "Climate Change in Continental Isotopic Records AGU Geophys." Monogr. 78:179-190.