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Geology topics

D. Rhode

Publications and source records attributed to D. Rhode.

2 recordsLinked to original sources

Late Pleistocene and Early Holocene lake-level fluctuations in the Lahontan Basin, Nevada: Implications for the distribution of archaeological sites

The Great Basin of the western U.S. contains a rich record of late Pleistocene and Holocene lake-level fluctuations as well as an extensive record of human occupation during the same time frame. We compare spatial-temporal relationships between these records in the Lahontan basin to consider whether lake-level fluctuations across the Pleistocene-Holocene transition controlled distribution of archaeological sites. We use the reasonably well-dated archaeological record from caves and rockshelters as well as results from new pedestrian surveys to investigate this problem. Although lake levels probably reached maximum elevations of about 1230-1235 m in the different subbasins of Lahontan during the Younger Dryas (YD) period, the duration that the lakes occupied the highest levels was brief Paleoindian and early Archaic archaeological sites are concentrated on somewhat lower and slightly younger shorelines (???1220-1225 in) that also date from the Younger Dryas period. This study suggests that Paleoindians often concentrated their activities adjacent to large lakes and wetland resources soon after they first entered the Great Basin. ?? 2008 Wiley Periodicals, Inc.

Geoarchaeology

Late Quaternary environmental change in the Bonneville basin, western USA

Excavation and analyses of small animal remains from stratified raptor deposits spanning the last 11.5 ka, together with collection and analysis of over 60 dated fossil woodrat midden samples spanning the last 50 ka, provide a detailed record of changing climate in the eastern Great Basin during the late Pleistocene and Holocene. Sagebrush steppe dominated the northern Bonneville basin during the Full Glacial, suggesting that conditions were cold and relatively dry, in contrast to the southern basin, which was also cold but moister. Limber pine woodlands dominated ???13-11.5 ka, indicating increased dryness and summer temperatures ???6-7??C cooler than present. This drying trend accelerated after ???11.5 ka causing Lake Bonneville to drop rapidly, eliminating 11 species of fish from the lake. From ???11.5-8.2 ka xerophytic sagebrush and shadscale scrub replaced more mesophilic shrubs in a step-wise fashion. A variety of small mammals and plants indicate the early Holocene was ???3??C cooler and moister than at present, not warmer as suggested by a number of climatic models. The diversity of plants and animals changed dramatically after 8.2 ka as many species disappeared from the record. Some of the upland species returned after ???4 ka and Great Salt Lake became fresh enough at ???3.4 and ???1.2 ka to support populations of Utah chub. ?? 2001 Elsevier Science B.V.

Palaeogeography, Palaeoclimatology, Palaeoecology