March 21, 1913] 



SCIENCE 



449 



sorting powers of streams of varying veloci- 

 ties, and nothing could more plainly show the 

 distance of the glacier and the stagnation of 

 the water than the varying thicknesses of 

 clean sticky clay which universally lie against 

 the rock floor of the region. Where bays to 

 one side of the line of current offered espe- 

 cially still water its thickness runs up to 100 

 feet. Even on the hillside at Warren near 

 the " old drift " and not far above present 

 water level the writer has found it and taken 

 fragments of wood therefrom. This presence 

 of the broken pieces of the old forest in the 

 clay is proof of a first invasion of the region, 

 and at Bradford, Clarendon, Stoneham and 

 elsewhere outside of the area of discussion the 

 heaps of accumulated logs were so well pre- 

 served as to make the driving of the pipe to 

 bed rock a most diiBcult operation. Even as 

 far down the river as Kittanning this clay is so 

 abundant as to furnish material for the manu- 

 facture of china. Above this the sequence of 

 deposits is a fine quicksand resembling a fri- 

 able clay; a coarser quicksand; sands, and, 

 finally, gravels. Where there was continuous 

 current action the lighter varieties are gen- 

 erally absent, and where it swept along one 

 side of a valley with torrential force even the 

 gravels are absent on that side, as at Warren, 

 Franklin, Brandon, Kennerdell and numerous 

 other places not noted in the many discussions 

 of this region. At Bradford, Stoneham and 

 Clarendon we have the whole series as it was 

 laid down, as shown by the thousand wells of 

 Bradford, the hundreds at Stoneham, and the 

 1,300 or more of the South Pennsylvania Com- 

 pany about Clarendon. 



Regarding the alleged " old gravels " which 

 are supposed to have been laid down in a river 

 bed whose bottom was several hundred feet 

 above present water-level, we find that they 

 vary in level A.T. 100 feet or more within a 

 few miles and around the shoulders of the 

 same hiU. Streams never run up hill and so 

 there was no stream deposition at such places. 



Coming from generalities to specific locali- 

 ties we find at Bradford, outside of the so- 

 called Kansan area, that the valley for miles 

 has a nearly flat surface, and the rock floor 



averages 200 feet below it. Taking the 

 Clarendon-Stoneham-Glade- Warren rock floor 

 of Carll's preglacial stream we find the drive 

 pipes at the first place will run from 200 to 

 310 feet. The last was located on and ran 

 through Mr. Leverett's " old drift." At Stone- 

 ham the average is 200 to 232 feet: at Glade, 

 100 feet : at Warren, and again on the " old 

 drift " are several wells which place the rock 

 floor on a slope running from present water 

 level to iifty feet below it. The averages of 

 the four localities above given show that the 

 floor dips from Clarendon to Warren and will 

 average 1,200 A.T., or below present water- 

 level. This being the fact, the " old drift " 

 patches are shown to be the youngest of a 

 regular series, and as the rock floor level was 

 determined before deposition began, there has 

 been here no " great erosion." For 60 miles 

 of the valley we can say " no erosion." 



At Franklin we find rusty gravel on the 

 hillside north of French Creek. The new 

 water works enabled the writer to inspect a 

 deep trench for the city mains which ran from 

 just above water-level to several hundred feet 

 up the mountain, where the reservoir was be- 

 ing built. As the trench went down to soil 

 rotting in place there was a chance to see the 

 soil line and to note that the sediments were 

 washes parallel thereto, and carrying the same 

 amount and kinds of foreign rocks throughout 

 all elevations exposed. Here also the " old 

 drift " lay on top of the wash, and there was 

 no " erosion." 



Parker was made much of, as here was an 

 alleged " abandoned loop " of a mythical Alle- 

 ghany of Kansan times. The writer showed, 

 more than a dozen years ago in Science, that 

 the wide difference in elevation, material and 

 dip of the deposits precluded their being laid 

 doviTi by a stream, and this was proved by the 

 usual oil well not very far from the Alleghany 

 which went down through the " old drift " to 

 below the present water level. 



We have now performed our task, the refer- 

 ence of the " old drift " at Warren, Clarendon, 

 Franklin and Parker to the present water 

 level, and in all these places it lies over the 

 old bottom as the uppermost of a regular 



