Deformation in response to landscape evolution during glacial cycles on the US Atlantic passive margin

摘要

Elevations of Pleistocene highstand formations that lie across the South Carolina and northern Georgia coastal plain lie well above those of reconstructed past sea levels. This discrepancy has been attributed to some combination of tectonics, glacial isostatic adjustment, and/or deviations in estimated ocean volumes derived from the marine delta O-18 record. To reconcile these anomalous elevations, we combine a landscape evolution model with models of coupled ice sheet, sea level and solid Earth deformation along the southern U.S. Atlantic passive margin to estimate erosion, deposition and corresponding isostatic response since Marine Isotope Stage (MIS) 11 (similar to 410 ka). We find that along-shore changes in modeled paleoshoreline elevations are similar to measured elevations along 100s of kilometers. Up to 10 m of shoreline uplift since MIS 11 may be attributed to isostatic feedback in response to sediment redistribution. (C) 2019 Elsevier B.V. All rights reserved.