Quaternary Reelfoot Fault Deformation in the Obion River Valley, Tennessee, USA

Blind reverse faults are challenging to detect, and earthquake records can be elusive because deep fault slip does not break the surface along readily recognized scarps. The blind Reelfoot in New Madrid seismic zone central United States has been subject of extensive prior investigation; however, extent at southern portion remains unconstrained. In this study, we use lidar map terraces lacustrine landforms Obion River valley investigate apparent broad folding resulting from on buried fault. We compare remote mapping results with three auger boreholes ?24 ka Finley terrace interpret warping as due tectonic stratigraphic thickening. combine our historical coseismic lake formation that indicate deformation dammed 1812 CE earthquake. Older (deposited least 35–55 ka) record progressive fold scarps ?1, ?2, ?8 m high indicating a long earthquakes predating existing paleoseismic record. Broad, distributed above into is consistent active tip reaches Our analyses entire length (?70 km) capable rupture more longer scenarios.