Geophysical Survey of the Stumpy Basin Landslide, Ohio

Abstract

The Stumpy Basin landslide occurs in a series of glacio-lacustrine silts and clays near the eastern abutment of the Ohio turnpike bridge which crosses the Cuyahoga Valley in northern Summit County, Ohio. These Pleistocene sediments overlie shaly bedrock along the flanks of the valley and in places are more than 100 ft thick. The surface of the landslide is dominated by a complex series of scarps, seeplines, and accumulations of slide material formed from many small rotational slumps, slab-slides, mud-flows, and creep events. Seven reversed seismic refraction lines and eight resistivity lines were run over the upper portion of the slide. The refraction data show a low velocity upper layer that is separated from the underlying high velocity undisturbed sediments by a complex refracting surface. Resistivity data similarly show a two layer system in which the low resistivity landslide mass cross-cuts the resistivity layering in the higher resistivity Pleistocene sediments. The geophysical data define the failure surface as a series of arcuate slip surfaces that coalesce into a single slip surface at depths of 12 to 35 ft.