Late hologene episodes of deformation along the central reelfoot scarp, Lake County, Tennessee

ABSTRACT

This research is desinged to assess Holocene tectonic defornmation in the Lake County uplift region, and to evaluate the recurrence of large - magnitude earthquakes in the Central New Madrid seismic zone. A 90-m long trench across the central reelfoot scarp exposed fluvial levee and overbank deposits overlain by colluvial deposits at the base of the scarp. Liquefaction related features include unweathered sand dikes and sills that intrude into the fluvial deposits. We interpret that the sand dikes and sills are results of the A.D. 1811-12 earthquakes, and that the colluvial deposits along the scarp estimated that the time between the two most - recent earthquakes large enough to produce liquefaction and/or surface deformation along the scarp is about 200 to 600 years (AU)