THE ALLEGED PARKER CHANNEL 463 



A. P. Brigham. The following communication from E. H. Williams, Jr., 

 was read by the Secretary as a part of the discussion : 



THE ALLEGED PARKER CH ANNUEL 

 BY E. H. WILLIAMS, JR. 



The Allegheny river from Irvineton to Red Bank, Pennsylvania, marks approx- 

 imately the edge of the earliest glacier. The ice moving up the valleys of northwest- 

 ern Pennsylvania went against drainage and produced slack water which has left 

 its deposits throughout the western part of the state. The elevation of this water 

 varies. About Warren it is above 1,600 feet above tide; about Franklin, above 

 1,400 feet above tide, and this level is carried to Foxburg, which is immediately 

 above Parker and not far from the northern end of the vertically walled gorge, that 

 replaces the valleys with sloping sides which obtain above Emlenton and below 

 Monterey. Below the level of slack water we find the surface capped with a de- 

 posit varying from sand to clay locally, and from a few inches in thickness to many 

 feet. It extends down to the present drainage levels, and is stratified parallel to 

 the underlying contours, so that we can conclude that those contours were deter- 

 mined before the deposition. In this slack water were dropped, wherever shoul- 

 ders of hills produced eddies, deposits varying from clean sand to accumulations 

 of boulders. The line of the current is shown by thin deposits and by the bosses 

 of hard rock polished by the sands and lying with slight covering. 



The alleged abandoned channel near Parker has been noticed so frequently that 

 it need not be described. It is sufficient to say that its highest part is about 250 

 feet above the rock floor of the Allegheny, and 190 feet above water level. The 

 glacial water level was 500 feet higher, or over 300 feet above the highest part of 

 this alleged channel, so that the gravels in the channel could have been laid down 

 from the overwash of the glacier and should vary in thickness and character ac- 

 cording to the manner in which the surface was presented to the glacial discharge. 

 This variation is seen readily on examining the region, as within short distances 

 we find at the same levels erratics and local fragments : rolled here, and locally 

 angular there. Sections show the same variation and disclose the fact that the 

 gravels do not rest on a bottom of uniform level. A number of oil wells have been 

 driven through this alleged river bottom. One of them was a mile from the river 

 and the drive-pipe passed through 50 feet of gravel underlaid by the same thick- 

 ness of quicksand. The bottom of the pipe was therefore about 50 feet above 

 present water level of the Allegheny, WhereVer thick sections can be studied 

 they present strata parallel to the old contours except in a bar laid in the south- 

 ern part of this alleged channel, which rises on all sides from the average level of 

 the filling, and its strata lie parallel to its surface. 



There are many other facts which can not be brought forward in small compass, 

 such as the difi'erence in levels of local deposits on opposite sides of the valley, 

 etcetera, which, combined with what had been given above, show that two short 

 side valleys rise on opposite sides of a low col and debouch into the Allegheny 

 gorge within a mile of one another, and in glacial times these two valleys were 

 filled by overwash deposits mingled with material from the imnaeiately adjacent 

 slopes. 



