Latest Pleistocene history of pluvial Lake Franklin, northeastern Nevada, USA
Jeffrey S. Munroe and Benjamin J.C. Laabs, Dept. of Geology, Middlebury College, Middlebury, VT 05753, USA. Posted online 29 Jan. 2013; http://dx.doi.org/10.1130/B30696.1.
Jeff Munroe of Middlebury College and Ben Laabs of SUNY-Geneseo investigate the history of Lake Franklin, which occupied the Ruby Valley of northeastern Nevada during the last Ice Age. Although the lake has completely dried up, mapping of preserved beaches allowed the former dimensions of the lake to be determined, and radiocarbon dating of fossil shells recovered from beach sediments at a variety of elevations allowed a history of lake-level changes to be reconstructed. Lake Franklin was present during the global peak of the last Ice Age; however, it covered only ~50% of its maximum area, suggesting that Ice Age climate in northeastern Nevada was cold and dry. Approximately 17,000 years ago, the lake rose rapidly to its maximum elevation, expanding to cover 1,100 square kilometers, making it one of the largest lakes in the southwestern U.S. at that time. This rapid lake-level rise was synchronous with expansions of other lakes in the region, implicating a climatic shift toward moister conditions. Approximately 15,000 years ago, the level of the lake fell rapidly as the climate became abruptly drier. This trend was temporarily interrupted by a short-lived lake expansion about 13,000 years ago, after which the lake disappeared completely.
Sediment dispersal in an evolving foreland: Detrital zircon geochronology from Upper Jurassic and lowermost Cretaceou
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