A long, almost varved sequence of late Pleistocene-Holocene laminations and bedding have been identified in the Estancia lake basin in central New Mexico. Remarkable vertical continutity of laminations and bedding provide a basis for reconstructing a stratigraphic time-series with decadel, centennial and millenial resolution. Methods originally applied to varved sediments will be adapted to reconstruct a time-series based on accumulated thickness of bedding and laminations and "tuned" with radiocarbon dates. Changes in water volume and expansion and contraction of the shallow lake are reflected in the rate of accumulation of clay, calcium carbonate, and eolean influx of gypsum sand. These parameters will be measured in closely spaced samples, indexed to the reconstructed time-series, and expressed as sediment flux. Correlation of high-stand shoreline deposits with basin-center strata will lead to the development of an advanced hydrologic- climatic model. The project will determine the feasibility of reconstructing high-resolution stratigraphic records in semi-arid lacustrine environments and at the same time evaluate the hydrologic- climatic sensitivity of a potentially important site and sediment record.
