Exhumation and Topographic Evolution of the Post-Orogenic Appalachians Determined by Apatite U-Th/He Dating

Lehigh University, Bethlehem PA

Investigators

Abstract

9909393 Pazzaglia Significant residual elevation of ancient mountain ranges is difficult to explain, but several examples of elevated mountainous topography in long-inactive orogens exist. This study will investigate the suggestion made by the presence of a large volume of post Miocene sediments in the Baltimore Canyon that as much as 3 kilometers of material has been removed from the New England Appalachians in the last 20 My, despite cessation of orogenesis nearly 200 My earlier. The project involves application of a relatively new radiometric technique that has the potential to detect and quantify denudation of such magnitude. Results are expected to test the possible recent exhumation in this area and to provide insight into intraplate and post-orogenic processes of rock-uplift.