Chickasaw Bluff

The Chickasaw Bluff is the high ground rising about 50 to 200 feet (20–60 m) above the flood plain between Fulton in Lauderdale County, Tennessee and Memphis in Shelby County, Tennessee. This elevation is named for the Chickasaw, who by their possession of the elevation impeded French river traffic in the 18th Century.

The Chickasaw Bluffs were numbered by rivermen from one to four starting from the north.

The Chickasaw Bluffs are a relatively recent feature. They were formed from loess (wind-blown) silt. This loess can be as thick as 70 feet and it generally tapers off as one moves eastward. The loess accumulated on top of fluvial deposits from the pliocene. These primarily consist of terrace gravels deposited from glacial runoff. Because of this, the bluffs are slide-prone, especially during seismic activity. The bluffs are characterized by very steep valleys and have higher gradient streams than areas to the east or west. Along the western edges facing the river or alluvial plains, they bluffs form nearly vertical cliffs. In Memphis, these edges have been smoothed out in the downtown area.

Although the Chickasaw Bluffs refer to the four numbered formations in Tennessee, the geological feature stretches from Hickman, Kentucky to around Baton Rouge, Louisiana. They do not form a continuous band, as they are split by river valleys such as the Obion River, Forked Deer River, Hatchie River, Loosahatchie River, Wolf River, Coldwater River, and Tallahatchie River.

...
Wikipedia