GEOMORPHOLOGIST'S PLAYGROUND: CUTOFF BEDROCK MEANDERS,SUBTERRANEAN STREAM CAPTURE, AND RECENT STREAM COURSE CHANGE FROM WINDOW CLIFFS TO BURGESS FALLS

Cane Creek arises on the west side of Cookeville, TN, on the Eastern Highland Rim, and flows southeastward for 24 km to its junction with Falling Water River. In its lower reaches it has incised a gorge up to 100 m into and through the resistant silicified Ft. Payne Formation. The most well-known geomorphic feature here is Window Cliffs, where undercut slopes on opposite sides of a meander neck have advanced toward one another, reducing the neck to a knife-edge ridge. The two “windows” (natural bridges) have been punched through weak strata exposed on the slope. Immediately upstream is a still rarer phenomenon – Cane Creek is being captured by its own tributary, Phelps Branch. As at Window Cliffs, two undercut slopes are advancing toward each other, but in this case they are slopes of two different streams. Furthermore, here pirating of the main stream is already taking place, as a sizeable fraction of the stream flow is being diverted from Cane Creek to Phelps Branch through a cave at the base of the ridge. Downstream from the junction of these two streams Cane Creek displays three cutoff bedrock meanders. The height of the meander floors above the present-day stream level provides a clue as to the relative age at which the cutoffs took place. On Falling Water River, about 1 km upstream from the junction of Cane Creek and Falling Water, lies Burgess Falls, perhaps the most spectacular waterfall on the Highland Rim. There is evidence that the course of Falling Water River has changed in the relatively recent past. About 2 km southeast of the junction of the two streams is Tibbs Hollow, a short valley occupied by a stream less than 3 km long. In this hollow lies an enormous cutoff bedrock meander, far too large to have been made by the small stream now occupying the hollow, and even too large to have been made by Cane Creek. Evidence is presented that an earlier ancestor of Falling Water once flowed through Tibbs Hollow. The corridor along Cane Creek from Window Cliffs to the junction of Cane Creek and Falling Water River, including Burgess Falls (now a State Natural area), and also including Tibbs Hollow, would make a superb expanded State Natural Area, allowing preservation of the scenery as well as the features discussed above for future geomorphology students.