THE GEOLOGIST'S TRAVELING HA^D-B'OOK. 



In Pennsylvania, the Vespertine is a white, gray and yellowish sandstone, 

 alternating with coarse silicious conglomerates, and dark-blue, olive and black 

 slates, and occasionally thin beds of coal. In Michigan, it is the Marshall group, 

 wjiich is mostly a somewhat friable rock, with a reddish, buffish, or olive color, 

 though in some regions becoming gray or bluish-gray. It forms the receptacle 

 into which the brine descends, and accumulates from the next over-lying Michigan 

 salt group, which is 13 b., and also sub-carboniferous. The Waverly group of 

 Ohio is proved, by its fossils, to be of this same age. Its sub-divisions are given 

 at the head of the chapter on Ohio. It produces the Berea grindstones and 

 Waverly sandstone, the finest building-stone in Ohio, if not in the United States. 

 In Tennessee there is a great development of the lower sub-carboniferous group, 

 the 13 a. Barren group, and 13 b. Coral, or St. Louis limestone, formerly called by 

 Prof. Safford the Silicious. Its upper part is the equivalent of the St. Louis lime- 

 stone of Missouri ; the lower is a series of silico-calcareous rocks, characterized by 

 heavy layers of chert, one inch to two feet thick. 



In Illinois the series of sub-carboniferous strata consists of the 1. Kinderhook 

 group, 2. Burlington group, 3. Keokuk group, 4. St. Louis group, the base of 

 which was formerly called the Warsaw limestone, and the 5. Chester group; all of 

 these are limestones and shale, with some sandstone in the first and last named. 

 These embrace both the lower and upper sub-carboniferous, and are 1,200 to 1,500 

 feet thick in the south-western part of Illinois, but thin-out in going north, and 

 entirely disappear before reaching Rock Island, where the coal-measures rest on 

 the Devonian limestone. In Iowa the four lower members occur, but the Chester, 

 the thickest member, is wanting, and it is almost entirely wanting in Missouri. 



, In Pennsylvania a small coal-bed has been opened on the Susquehanna River, 

 in the Pocono sandstone ; and in Huntingdon County more than a dozen small 

 layers of coal may be traced, running through the formation. In Montgomery 

 County, Virginia, two similar coal-beds attain a local importance, being on Tom's 

 Creek, respectively 4 and 8 feet thick. These represent the lower coal of East 

 Kentucky, Tennessee, and Alabama. 



In Ohio the Subcarboniferous limestone extends through some of the south- 

 eastern counties. It is quite thin, and represents only the upper or Chester member 

 of the group. Two workable seams of coal the Jackson and Wallston coals 

 are found below it. Newberry. 



13 b, Upper Sub-Carboniferous. In Pennsylvania this is the Umbral red 

 shale of Rogers, and the Mauch Chunk of Lesley, sometimes 3,000 feet thick, and 

 here consists almost entirely of very soft red shales and argillaceous red sand- 

 stone, without fossils. It gradually becomes in Virginia a triple mass of buff, green 

 and red shales below, a thick body of light-blue limestone, full of fossils, in the 

 middle, and the upper part blue, olive and red calcareous shales, with massive 

 strata of gray and brownish sandstone. It contains beds of iron ore, which are 

 sometimes very valuable. In the Western States the limestone is the principal 

 rock. It is the limestone of Greenbriar Valley in West Virginia. In Northern 

 Pennsylvania, gray and greenish shales, and gray argillaceous sandstones, are 

 introduced among the red shales, and farther west it consists of two or more strata 

 of soft red shales, separated by a thick body of gray, flaggy sandstone. It is 

 generally well marked in Pennsylvania as the softest of rocks, or simply dry red 

 mud, and is to be noticed by those in search of coal, none of which is ever 

 found in or below it. In Tennessee this formation is the mountain limestone, 



