419 



and Spencers He accounts for "The Narrows", as this very constricted 

 portion of the river valley is called, by asserting that this portion of the 

 valley is new, having been formed since the Illinois glaciation. The old 

 channel, he says, was up McCormicks Creek, through the Flatwoods basin, 

 and back to the present channel by way of Raccoon Creek. Leverett 

 says: "The stream (White River) is now occupying a pre-glacial valley 

 for a few miles in southwest Morgan County, and is also in a pre-glacial 

 valley throughout much of its course below Owen County. But in its 

 passage across Owen County it is opening a new valley. It has been sug- 

 gested that this stream had a subterranean passage across the sink-hole 

 region of Owen County, in which case no well-defined surface channel may 

 have been opened prior to the glacial invasion." (The Illinois Glacial Lobe 

 pp. 104, Monograph XXXVIII, U. S. Geol. Surv.) 



Both Collet and Leverett have expressed their belief that White River 

 in its present passage across the Mitchell limestone region is in a new 

 valley. Collet says that the old channel was through McCormicks Creek, 

 Flatwoods basin and Raccoon Creek. Siebenthal, in regard to Collet's 

 idea, says : "The Pleistocene terraces of Bean Blossom Creek clearly 

 prove the pre-glacial valley of that creek to have been practically as it is 

 at present. It is impossible to imagine how it could be cut down to its 

 present depth, while White River, into which it emptied, was running at a 

 level 150 feet higher than now, as it is alleged to have done. Moreover 

 the gorge of McCormicks Creek is clearly post-glacial. And further, it 

 empties into WTiite River at least a mile below the upper end of the 

 "Narrows," whose existence it was brought forward to explain." (Twen- 

 ty-first Annual Report, Ind. Geol. Surv., 1896, pp. 302). Thus Seibenthal 

 makes it clear that Collet was in error in regard to the ancient channel of 

 White River in the Mitchell limestone region. 



Leverett asserts that White River in Owen County is post-glacial, and 

 suggests that the pre-glacial drainage was a series of channels through 

 the limestone region. The writer in his examination of the area found no 

 evidence of an ancient channel on either side of the present river in the 

 limestone region of Owen County ; and there is little, if any, evidence of 

 its passage through the region ever having been subterranean. 



The constriction of the river just above Spencer is undoubtedly 

 remarkable, and not geologists alone have asked the why of it. Puzzling 

 as the "Narrows" are, they have a rather simple explanation. The valley 

 here is very narrow in comparison to the extremely wide portions above 



