Miocene uplfit of the Southern Appalachian Mountains inferred from the geomorphic history of the Tennessee River

The modern Tennessee River has its headwaters near Knville in east Tennessee and flows 652 miles across eastern and central Tennessee, northern Alabama, forms a small segment of the Alabama-Mississippi state line, then turns and flows due north and crosses eastern Tennessee and western Kentucky to merge with the Ohio River. The ancient or Old Tennessee River of late Cretaceous-Miocene age flowed in a more direct southeast path extending 320 km from east Tennessee to an area east of the present-day Mississippi delta where it formed a large delta called the Old Tennessee delta. There are two previous models for the rocks of the Appalachian orogeny that underlie and now control the unusual, modern U-shaped course of the river. One idea is that the present topography has persisted for long periods of time by variable erodibility of rock units. The second idea is that the southern Appalachians experienced an uplift event in the last 10 my related to either climate change or a mantle process. In this study, I use Google Earth images to document previously undocumented areas of Tennessee wind gaps in the Alabama ridge that separates the Mississippi and Tennessee river valleys.