274 



SCIENCE. 



[N. S. Vol. XVI. No. 398. 



sidered a part of our science. Paleobotany 

 has legitimate troubles enough of its own with- 

 out being taxed with this. It is diificult to 

 understand how the publication committee of 

 the Ohio State Academy of Science could have 

 admitted this paper, at least in its present 

 form. 



F. H. Knowlton. 



GEOLOGICAL EXCURSIONS IN THE PITTS- 

 BURGH COAL REGION. 



The Pittsburgh meeting of the Geological 

 Society of America and of Section E of the 

 A. A. A. S. was rendered memorable to ni.iny 

 geologists by the opportunity afforded them '.o 

 study the stratigraphy of the bituminous coal 

 fields of Pennsylvania and West Virginia, un- 

 der such an experienced and enthusiastic 

 guide as Professor I. C. White. About 

 twenty geologists and students assembled at 

 the Pennsylvania station on Tuesday morn- 

 ing, June 24, for the 6.15 train. The 

 first objective point was Garver's Perry, oppo- 

 site Preeport, on the Allegheny River. This 

 is the type locality for the Upper and Lower 

 Preeport coals, and these with their accom- 

 panying shales, fire-clays and sandy beds 

 were studied. An interesting feature was 

 the occurrence of limestone beds in this coal 

 series, which in some eases lay directly be- 

 neath the coal, and in others were associated 

 with the fire-clay. Prequently both fire-clay 

 and limestones were replaced by the sandstones 

 of the series. 



The Preeport sandstone underlying the 

 coal series was seen in the river bed. The 

 lowest member of the Conemaugh or Lower 

 Barren series in this region is the Mahoning 

 sandstone group, which often includes a thin 

 seam of coal (Mahoning) and sometimes 

 calcareous beds. The overlying Masontown 

 coal and the red beds higher up, nearly to the 

 horizon of the Crinoidal limestone, were stud- 

 ied in a walk of several miles and a climb up 

 the steep rocky cliffs. This brought before 

 the party the entire lower half of the Cone- 

 maugh, up to the horizon of the rocks ex- 

 posed at Pittsburgh. The upper portion of 

 the Allegheny or Lower Productive series 

 (Preeport coal group) was also included. 



At Kittanning, further up the river, the 

 study of the Allegheny series was taken up 

 again, and this time nearly the entire series 

 was seen from the Clarion Coal, twenty-five 

 feet above the Pottsville, to the Upper Free- 

 port coal, and also the overlying Mahoning 

 sandstones of the Conemaugh series. Special 

 attention was called to the Ferriferous lime- 

 stone and the Kittanning coals in this sec- 

 tion. Still farther up the river at the mouth 

 of the Mahoning, the greater portion of the 

 Pottsville series as brought up by the Kellers- 

 burg anticlinal, was studied. The lower or 

 Oonnoquenessing sandstone with its included 

 Quakertown coal, and the upper or Home- 

 wood sandstone with the intermediate Mercer 

 coal groups, were pointed out. 



On the return journey a stop was made 

 at Crag Dell and a short walk along the rail- 

 road tracks enabled Dr. White to point out 

 many of the interesting detailed character- 

 istics of the Upper Preeport coal and its 

 associated rocks. 



On Wednesday the party visited the inter- 

 esting region about the junction of the Oon- 

 noquenessing with the Beaver, and here the 

 Homewood and Upper and Lower Oonnoque- 

 nessing sandstones were studied at their type 

 localities. Some of the lower members of the 

 overlying Allegheny series were also studied, 

 especially the Ferriferous limestone. Later in 

 the day, near Beaver, the Brookville and 

 Clarion coals with the intervening Eagle 

 limestone were seen, thus completing the base 

 of the Allegheny series. 



The interesting glacial phenomena along 

 the Beaver, below the terminal moraine, were 

 given special attention, and the evidence of 

 the former impounding of the waters in the 

 preglacial river valleys of the Ohio and its 

 tributaries by the front of the ice sheet, as 

 pointed out by Dr. White, was pronounced 

 very conclusive. Attention was also given to 

 the character of the preglacial valleys, and 

 the high-level terraces on either side of the 

 Ohio and the Beaver, and their gradual de- 

 scent northwestward, forcibly suggested the 

 former northwest drainage into the Lake Erie 

 Valley of the river systems of this region, as 

 pointed out by White, Hice and others. 



