REVIEW OF GEOLOGICAL STRUCTUKE. 21 



were quite different from what they are along the northern line of out- 

 crop.* 



But any description of the Waverly group, as it appears on the Western 

 Reserve, would be very incomplete and inaccurate that did not i^pecify 

 and define the marked subdivisions which it shows, aud it has greatly 

 facilitated both the communication and the acquisition of a knowledge 

 of the formation to give to these subdivisions distinct names. The cus- 

 tom of attaching local names to well marked subdivisions of geological 

 formations, has been followed since men began to write on gfology, and 

 it will unquestionably continue to be followed as long as geological sur- 

 veys aqd explorations shall be made. Beyond the region where the local 

 subdivisions of a formation are distinguishable, the local classification 

 will not hold, but in the district where the Barea grit is well defined, 

 and where, as on the Reserve, it is literally a mine of wealth to the cit- 

 izens — furnishing building stones, grindstones, etc., to the amount of a 

 million of dollars annually — it is a matter of great practical consequence 

 that it should be carefully described and its place in the series be accu- 

 rately defined. To do this, it was indispensable that it should receive a 

 distinct name. 



5. The Cuyahoga shale, stated in the above paragraph to be identical 

 with the umbral of Rogers, and to reach in Pennsylvania a thickness of 

 3,000 feet, is simply one of the local subdivisions of the Waverly in 

 northern Ohio, and is not recognized in the central and southern parts 

 of the State. Its identification with the umbral of Rogers, is not sup- 

 ported by any satisfactory evidence. 



6. The Berea grit is supposed, by Professor Lesley, to split into two 

 parts in passing into Pennsylvania, the upper one to become the '' Ves- 

 pertine " or " First Mountain Sand," the lower to descend and form the 

 Chemung Conglomerate at Chautauqua Lake and Olean, New York. It 

 is scarcely necessary to say that this view is entirely untenable The 



* On page 97, note, Professor Lesley says: "Dr. Newberry, in liis Report of Progress 

 of the Ohio Survey, for ItiTO, page 59, divides it (the Waverly) into three mcmhers — 

 upper, middle, and lower — the Middle Waverly being a Congloaierate. This is the Be- 

 rea grit and the New York 'Conglomerate;' onr Venango Second Mountain sand. But 

 iu the report of 1373, the Ohio geologist divide the Waverly i;r>up iuto four for.uatinns 

 — Cuyahoga, Berea, Bedford, and Cleveland." This piragra;>h contains three erroraj 

 ■which req'iire correction. (1) It was Professor A'ldrews who divided the Waverly into 

 three members in soubhorn Ohio, Dr. Ne.vberry into four in northern OjIo; ('2) there is 

 no evidence that tha Middle Conglo nerate of t''iiir(i>ld ouity is identical with the 

 Berea, and it is quite certain that neither are the equivalents of the ' Conglomerate ' of 

 New York, for they are Waverly and that is Chemung ; and ( f) the " New York Con. 

 glomerate " is not the equivalent of the " Second Mountain saud " of Penus^ Ivania. 



