Paleoclimatic Significance of High Latitude Loess Deposits,
ALASKA UNIV FAIRBANKS
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Loess deposits reflect changing environmental conditions in terrestrial regions, and contain long paleoclimatic records analogous to those found in marine sediments, lacustrine sediments, and ice sheets. Alaskan loess was deposited at rates of ca. 0.05-0.5 mm yr-l during the last 2-3 x 106 years loess deposits contain some of the longest and most complete proxy climate records yet found. New analytical methods are used to reconstruct changes in climate and atmospheric regime including wind intensity, storminess, temperature, and precipitation. Loess also contains a history of permafrost and paleosol formation, volcanic eruptions, and paleoecologic changes in high latitude regions, as well as Quaternary fossils and early man sites and artifacts. Time series analysis of proxy climate data from loess supports the astronomic model of climate change, although some transient climate events recorded in loess records are too short to be explained by orbital insolation forcing, and may instead correlate with rapid, short-term changes in atmospheric C02 and CH4 content.
- Soil Mechanics