603 



OHIO. 



plates of fossils of ne\v species discovered 

 during the progress of the survey. The second 

 volume of the final report is devoted to Eco- 

 nomic Geology, and includes descriptions of the 

 ores, coals, clays, limes, etc., with descriptions 

 of methods and statistics of production in all 

 branches of manufacture iron, steel, pottery, 

 etc. based on mineral staples. The final 

 report will consist of four volumes, with a 

 map. 



The second annual volume of the u Progress 

 Report of the Survey " details the work of 

 1870. Prof. Newberry, the Chief Geologist, in 

 the opening of his introductory report in the 

 volume, gives a sketch of the structure of the 

 lower coal-measures of Northwestern Ohio, 

 that is, of the group of seven, in some places 

 eight workable beds, which lie below the 

 Pittsburg seam, and include most of the im- 

 portant coal-strata of the State. Instead of 

 one symmetrical basin with a tolerably uniform 

 dip toward the southeast, the coal-measures 

 form several troughs, in a general way parallel 

 with the axis of the great one of which they 

 are parts. On the east side of each of these 

 subordinate basins the strata rise, or are hori- 

 zontal, and the easterly dip is neutralized ; so 

 that, on the east line of Columbiana County, 

 and within forty miles of Pittsburg, the centre 

 of the coal-basin, the section of the hills is 

 nearly the same with that found on the banks 

 of the Killbuck, one hundred miles west, the 

 average dip in this interval being not more 

 than three feet to the mile. From Nashville, 

 Holmes County, to the valley of the Killbuck 

 (Holmesville and Millersburg), the dip is east- 

 ward and somewhat rapid. From Millersburg 

 to th east line of Holmes County the strata 

 rise ; then dip again eastwardly into the valley 

 of the Tuscarawas. From Dover, to and be- 

 yond the tunnel, on the Tuscarawas Branch 

 Railroad, and to Carrollton, on an east and 

 west line, the dip is westwardly, while from 

 the Hanover Summit it is eastward to the 

 State line. 



The importance of the knowledge thus gained 

 will be apparent at a glance. For example, 

 it shows that the Briar Hill coal, or its horizon, 

 is within easy reach all along the valleys that 

 cut this portion of the coal-basin, and that it 

 is not, as has been represented, carried by a 

 uniform easterly dip so far below the surface 

 as to be practically inaccessible. Investiga- 

 tions during the past summer also show that 

 the number of coal-seams constituting the 

 lower group that is, those below the Barren 

 Measures has been erroneously duplicated; 

 that there is no break or confusion of the 

 strata, as has been stated, at the Hanover 

 Summit, the coal-seams being simply buried so 

 deeply there as to be invisible ; also, that the 

 Salineville coals do not dip under those exposed 

 in the lower portion of the Yellow Creek 

 Valley, but are really the highest of the lower 

 group, are immediately overlaid by the Barren 

 Coal Measures, and are identical with the 



highest three seams of the Hammond svillo and 

 Linton sections. 



Some of the general conclusions to which 

 the professor comes are, that there is no seam 

 north of the National Road (except the Briar 

 Hill) which will supply a first-class furnace- 

 coal ; that some process must be adopted for 

 ridding these coals of sulphur before they will 

 become available for important uses ; that they 

 may be used largely for the manufacture of 

 illuminating gas ; but that the best use to 

 which they can at present be applied is for 

 fuel for locomotives. Burning, as the cannels 

 do, so much like wood, they can be used in 

 ordinary locomotive-furnaces with little or no 

 change ; and, since their heating-power is twice 

 that of wood, and they crop out along the 

 sides of several of the railroads, they seem 

 destined to supply the place of wood, now in 

 many places becoming somewhat scarce. 



The professor next takes up the subject of 

 iron-ores in this section of the State, and traces 

 the Kidney ores through Holmes, Columbiana, 

 Tuscarawas, Mahoning, and Stark Counties. 

 He thinks their value has been somewhat over- 

 rated, inasmuch as, by the washing away of 

 the shales which originally contained them, 

 they have been concentrated in the surface 

 materials, where they have been readily acces- 

 sible and most cheaply mined. When, after 

 a longer or shorter time, these surface ac- 

 cumulations shall have been exhausted, he 

 fears that it will only be in rare instances that 

 these ores will be found of sufficient richness 

 to pay for drifting. 



It sometimes happens, as at Latonia, that 

 the roof-shale of a coal-seam is charged with 

 iron, and becomes a black-band ore. This 

 can then be removed with little trouble or cost. 

 Such associations of the fuel and the ore are 

 known to occur in several localities, and it is 

 probable that others will be found as a reward 

 to future search. 



Nearly every coal-seam in the series is un- 

 derlaid by a bed of fire-clay of greater or less 

 thickness. Usually these clay -beds are three 

 or four feet thick ; but that which underlies 

 the " strip vein " on Yellow Creek is some- 

 times twelve feet. These clays differ much in 

 character and value, but every county within 

 the coal-area may be said to possess abundant 

 supplies of this useful mineral. 



Among the other useful minerals of the 

 lower coal-series, the hydraulic limestones 

 should receive some notice. These are lime- 

 stones with which was mingled in their de- 

 position a larger or smaller quantity of clay, 

 and this imparts to them the property of form- 

 ing a mortar which hardens under water. 

 Limestones possessing the requisite properties 

 are found in various parts of the State^and at 

 several geological levels, especially in the 

 Upper Silurian strata, which from this circum- 

 stance have received the name of the Water- 

 Lime Group. Argillaceous limestones are, 

 however, not confined to this group. The 



