1875.] "iUi [Stevenson. 



Ill these sections the interval varies from 233 to 420 feet. In another 

 boi'ing, which passes through both the coal and the limestone, the dis- 

 tance is 364 feet. Two other wells were driven to a depth of 386 and 397 

 feet respectively below the coal, without reaching the limestone. In all 

 these wells the succession of strata is strikingly similar, though there is 

 no resemblance in the thickness of individual layers. It seems quite 

 probable that the interval is not far from three hundred feet, making all 

 due allowance for exaggerated thickness owing to ii-regular dip of the 

 rocks. The abrupt variations in the interval can be accounted for only 

 by supposing that the strata are not only broken, as they usually appear 

 in many of the railroad cuttings, but also actually crushed by lateral 

 l^ressure, as indeed is shown in one of the illustrations given above. 

 That this crushing is a common phenomenon appears from the frequent 

 occurrence of the term " floating sand " in the records. 



The record of one boring gives, as overlying the limestone, " 18 feet of 

 sandstone and coal.'''' Since this coal is referi-ed to in no other record, I 

 am inclined to regard the statement as an error. AJbove the main coal 

 and separated from it by a thin stratum of shale, there is in every in- 

 stance a sandstone, whose thickness appears to vary from 20 to 80 feet. 

 On this in two localities and eighty-five feet above the main bed is a thin 

 coal, two feet thick, and, at one place, still another seam, of similar 

 thickness occurs sixty-three feet higher. Above are shales for a consid- 

 erable distance, probably two hundred feet. These borings confirm the 

 conclusion, previously given, that the main coal is the Upper Freeport of 

 Pennsylvania, the No. VI of Ohio. 



Eleven of the borings pass through the limestone and five others show 

 by their sections that they have stopped not far short of it. In fourteen 

 of these, the overlying rock is described as sandstone and in the other 

 two as sandy shale. In twelve instances the sandstone is more or less 

 conglomerate. Respecting the limestone I have no direct information. 

 It is seen in a run near the railroad, a short distance east from Laurel 

 Junction, but no search has been made in it for fossils. Under the lime- 

 stone, sandstone occurs in ten borings and black shale in one. In four 

 instances the sandstone is quite conglomerate. Below the sandstone is 

 the variegated shale, whose thickness is unknown. Near the Staunton 

 pike it is more than seven hundred feet. 



This succession leaves no room to doubt that the overlying rock is the 

 Great Conglomerate, that the limestone is the Lower Carboniferous lime- 

 stone (Umbral) and that the underlying rocks are the Waverly Conglom- 

 erate and shales (Vespertine). 



Oil is found in the Great Conglomerate as well as in the shales and 

 conglomerate of the Waverly. The heavy lubricating oil, for which this 

 district has been celebrated, occurs at the upper horizon, while the lighter 

 oils are obtained at greater depths. Dr. Sharp informs me that extensive 

 *' water- veins " are seldom encountered in the borings. 



A. p. S. — VOL. XIV. 2z 



