How was crowley's ridge formed?

Answer 1

There has actually been some recent debate about Crowley's Ridge formation. It was original thought to have been an island that stood in between the Mississippi and Ohio rivers until the rivers changed course. New research shows that it is the result of periglacial loess deposits building up over time.

Answer 2

Crowley's ridge started forming in the Cretaceous period about 165 million years ago. It was not actually an Island, but a tectonic fault line that became a gravel bar. The Mississippi River was on the west side of the ridge and the Ohio River was on the east side. The two rivers were both trying to find the path of least resistance to become the dominant river system. they pushed against each other constantly depositing gravel along the fault line. over the years the level of the gravel bar rose to create the majority of the ridge. some time in history a seismic event caused a Natural Dam to brake which changed the course of the Mississippi River and allowed the Ohio River to capture the Mighty Mississippi. The final part of the Ridges development came in the form of wind blown Loess, or Silt. If wind blown Silt was the main factor in how the ridge was formed, then how did the gravel get here? Wind does not push tennis ball sized chunks of gravel around, but water does. The ridge was formed by a combination. of both water and wind depositing material along the Reelfoot rift which is beneath Crowley's Ridge.