604 



OHIO. 



tipper or Chester portion of the carboniferous 

 limestone series. The carboniferous conglom- 

 erate is the sheet of sandstone and pebble- 

 rock, known in the Old World as the " Mill- 

 stone Grit," and which underlies, there as 

 here, so much of the coal-measures. In the 

 northern part of the State it has a maximum 

 thickness of 160 feet. Toward the Ohio it is 

 much thinner and frequently wanting. It con- 

 sists of beds of coarse sandstone, with strata, 

 many feet in thickness, of conglomerate in 

 which the pebbles are generally quartz. Its 

 fossils are usually land-plants, similar to those 

 found in the coal-rocks above. In several lo- 

 calities many of the pebbles of the conglomer- 

 ate are balls of chert (flint), and contain fossils 

 which seem to prove that they were derived 

 from corniferous limestone, in which such con- 

 cretions are so common as to have suggested 

 the name given to the formation. Prof. New- 

 berry is of opinion that all the materials com- 

 posing the conglomerate have been brought 

 from the north, and distributed much in the 

 same way as the gravels of the drift were, 

 through the agency of ice. Along the margins 

 of the carboniferous conglomerate, gold has 

 been found in various localities of the State. 

 This gold, the chief geologist is inclined to be- 

 lieve, is derived from auriferous quartz, of 

 which the conglomerate is in part composed. 

 In other localities it is possible that the gold 

 has been derived from the more modern 

 gravels, transported by drift agencies from the 

 Canadian highlands. No considerable quantity 

 of gold will ever be found in these or any 

 other of our Ohio rocks, and all anticipations 

 of successful gold-mining here are sure to end 

 in disappointment. 



The portion of the great Alleghany coal- 

 field lying within Ohio covers nearly one- 

 third of the State, or from 10,000 to 12,000 

 square miles. As in this area the rocks all dip 

 toward the east, it is evident that the coal- 

 measures are thickest on the eastern border. 

 There they reach in places a thickness of 1,200 

 feet, and include ten or twelve workable seams 

 of coal. These are divided into the upper and 

 lower coal-measures, separated by the " barren 

 measures." The lower group of coals consists 

 of six to eight workable seams their thickness 

 and number varying somewhat in different 

 localities and these constitute the mineral 

 wealth of, by far, the larger part of our coal- 

 basin. The barren measures consist of heavy 

 beds of highly-colored (often red) shales, with 

 little or no workable coal. These red shales 

 form a conspicuous horizon, running through 

 the highlands from Marietta to Yellow Creek. 

 The first of the upper group of coals is the 

 Pittsburg seam, and this, with several which 

 overlie it, are found in the hills bordering the 

 Ohio, between Steubenville and Marietta. All 

 the coals of Ohio are classed as " bituminous 

 coals," but they include all known varieties of 

 this class, as the open burning or furnace coals, 

 such as the Briar Hill and Hocking Valley coal, 



the coking or " gas " coal., and the canncl 

 coals. Iron-ores of three varieties are found as- 

 sociated with the beds of coal, viz. : the argil- 

 laceous carbonate of iron (kidney or nodular 

 ore), "black band" a bituminous shale im- 

 pregnated with iron, and "block ore," usually 

 a limestone highly charged with iron. Also 

 limited supplies of brown-hematite formed 

 from the decomposition of the carbonates. Of 

 all these ores Ohio has rich deposits in various 

 localities. The fossils of the coal-measures 

 include great numbers of both animals and 

 plants; the plants being the most character- 

 istic, and so well known as "coal-plants " as 

 not to require description. The animal re- 

 mains consist of amphibians, fishes, Crustacea, 

 mollusks, crinoids, and corals, of which many 

 species in each group are found in Ohio. 



The drift deposits exhibit several interesting 

 features. In common with a large part of the 

 Northern hemisphere, all portions of Ohio, ex- 

 cept the summits of the hills bordering the 

 Ohio River, exhibit marks of glacial action in 

 the planing, polishing, and grooving of the sur- 

 face-rocks. Upon this glaciated surface, in a 

 few localities, are beds of unstratified gravel 

 and bowlders, evidently transported and de- 

 posited by glacial action, just as moraines are 

 formed by the glaciers of the present day. 

 Much more generally the glacial surface is 

 covered with a considerable thickness of fine 

 stratified clays, called the "Erie Clays," by 

 Sir William Logan. These clays contain nu- 

 merous small fragments of adjacent rocks, and 

 are evidently the flour ground by glaciers, in 

 their movement, deposited in water-basins 

 which occupied the places of the glaciers, as 

 these latter retreated northward. Above the 

 " Erie Clays," we have, in many places, a sheet 

 of carbonaceous material a black soil trunks 

 and stumps of trees, peat-beds, etc., which in- 

 dicate a forest-growth in a cold climate, over 

 much of Ohio and adjacent States. Above the 

 forest-bed are sands, clays, gravel, and bowlders 

 the latter generally of Canadian orign none 

 of which could have reached their present 

 resting-places except by a second submergence 

 of the Drift area, and the floating power of 

 icebergs. Upon the uppermost Drift sheet are 

 terraces and beaches, which mark intervals of 

 stability in the gradual recession of the water- 

 surface to its present level. 



During the season of 1870 the detail work 

 of the survey was proceeded with. In the 

 course of a very careful study of the coal- 

 strata in the northeastern section, Prof. 

 Newberry found that, instead of forming one 

 symmetrical basin, with a tolerably uniform 

 dip toward the southeast, the Ohio coal-meas- 

 ures form several troughs, more or less par- 

 allel with the axis of the great one of which 

 they form part. On the east side of each of 

 these subordinate basins, the strata rise, thus 

 neutralizing the general easterly dip, so that, 

 on the east line of Columbiana County and 

 within forty miles of Pittsburg, the section 



