Montlake - Lake on the Mountain

Located in Hamilton County, Tennessee, near Chattanooga, this is one of the most interesting natural lakes, of which Tennessee has few. Montlake, Hamilton County, Tennessee 2
Initial investigation of this feature, by myself, and early Tennessee geologists suggested that this was a sinkhole. It's round shape certainly makes it appear so, but that it sits on the Cumberland Plateau, on top of hundreds of feet of sandstone makes that less likely.

Later investigation points at this feature being caused by the slump of sandstone calving off the Plateau. That is supported 1) by its proximity to the edge of the Plateau and 2) by some canyon-like features running from the lake parallel to the cliffs of the Plateau.

I am not sure that either explanation alone sufficiently explains this feature. In my novice opinion it seems that it's both slump and karst. Which happened first is hard to tell, but slump doesn't explain the morphology, and fails to explain the nearby karst springs below. Karst fails to explain how the feature can exist through so many hundreds of feet of sandstone.

I welcome a more thorough explanation by someone who has investigated it first hand. It seems though that the experts on this are all long dead.

This feature is on private property, please respect the landowner and obtain permission before visiting.

Laurence, Robert A. "Sinkholes of the Cumberland Plateau." The Journal of Geology 1937 45:2, 214-215. Web.
Stockdale, Paris B. "Montlake: An Amazing Sinkhole." The Journal of Geology 44.4 (1936): 515-22.
Wilson Robert L., 1984: Slump features at Montlake in southeastern Tennessee; previously misinterpreted as a sinkhole. Abstracts with Programs - Geological Society of America 16(3): 206

Montlake, Hamilton County, Tennessee 1 Montlake, Hamilton County, Tennessee 3