THE EFFECTS OF UNDERLYING FISH CANYON TUFF BEDROCK ON SUBSURFACE RUNOFF DYNAMICS AND SOIL PRESERVATION AT THE LANNING SITE, GUNNISON COUNTY, CO

Like many of the archaeological sites located in the Gunnison Basin, Fish Canyon Tuff forms much of the underlying bedrock. Additionally, soils in Gunnison tend to be loess deposits that undergo intense cryoturbation and weathering. At Lanning however, pockets of non-lithified Fish Canyon ash (laden with absorbed groundwater) have served as stabilizing mechanisms for overlying soil deposits in some areas of the site. At Lanning, a site subjected to intense runoff, underlying pockets of ash have made some soil deposits more resilient to erosion and weathering.