36 THE GEOLOGIST'S TRAVELING HAND-BOOK. 



In Pennsylvania, ninety feet of strata have been carefully studied and measured 

 on Sideling Hill, consisting of alternate beds of red and olive shales and sandstones 

 with Chemung fossils, ripple-marks and f ucoids, and a bed of iron ore long known 

 by the name of the Larry's Creek ore, which outcrops everywhere along the face 

 of the Allegheny Mountain. In the gaps at Blairsville and Connellsville, hi 

 Southwestern Pennsylvania, Prof. Stevenson finds Chemung fossils in what have 

 always been called the Catskill rocks, on account of their being of a red color, 

 and other geologists have made the same observation in Northern Pennsylvania. 

 In Southern New York, adjacent to Pennsylvania, Professor Hall reports 150 feet 

 of red rocks, and then thin gray rocks above with Chemung fossils. 



The Erie shale of Ohio is the equivalent of the 11 b. Chemung, and the upper 

 part of the 11 a. Portage. At Cleveland, it consists of green, gray and blue shales' 

 soft and fine, with sheets of micaceous, silvery sandstone, from half an inch to two 

 inches in thickness, and flattened masses of argillaceous iron ore. Newberry. 

 The formation also occurs in Kentucky, and Chemung fossils have been found in 

 Utah and Nevada by Clarence King and Arnold Hague. 



12. Catskill. There is no observable line of demarcation between the 

 Chemung and Catskill. The first sign of change is a more solid or hard rock 

 appearing, often accompanied by red sandstone or red shale. The group consists 

 of light colored gray sandstone, usually hard ; of fine-grained red sandstone, red 

 ghale or slate ; of dark colored slate and shale, of grindstone-grit, and a peculiarly 

 accretionary and fragmentary mass, appearing like fragments of hard elate 

 cemented by limestone, similar to what is well known in England as cornstone. 

 The hard gray sandstone often presents a highly characteristic structure, the 

 layers, one or more inches thick, being disposed in oblique divisions, the divisions 

 usually overlapping each other. This peculiar angular arrangement presents 

 altogether a singular conformation, and forms a highly picturesque rock. V. 

 You can see this at Ralston, Pennsylvania. 



The prevailing color of the sandstone is brick-red, though often it is lighter, 

 and sometimes of a deeper color, from a larger proportion of iron, while the 

 coarser parts are often gray, and the shales are green. Beds of green shaly 

 sandstone are interstratified with the red friable sandstone, and these are succeeded 

 by a compact kind of conglomerate rock. The formation expands, and augments 

 in thickness, in passing eastward, till it finally rises in the high and prominent 

 peaks of the Catskill Mountain, nearly 4,000 feet above the sea, from which the 

 formation derives its name. See note No. 9, of New York. 



The formation extends from this locality southwestward into Pennsylvania, 

 where its outcrop, 3,000 feet thick, in combination with that of the Pocono 

 sandstone above it, 2,000 feet thick, forms a terraced mountain, which surrounds 

 each of the Anthracite coal fields ; the red rocks of the Catskill making the terrace, 

 and the white rocks of the Pocono forming the crest. Piled upon one another in 

 inclined strata, they constitute the bulk of the Catskill Mountains in New 

 York, of the Pocono plateau in Pennsylvania, and the Allegheny, Savage and 

 Cumberland Mountains, far into Virginia and Tennessee. 



On all the railroads approaching the anthracite coal regions of Pennsylvania 

 one passes over these Catskill rocks, often' for many miles. They contain no coal, 

 but fossil ferns are abundant in some localities. This is the last and upper forma- 

 tion of the Devonian period, and is the foundation on which rests the carboniferous 



