GEOGRAPHICAL CHANGES DURING PENNSYLVANIAN 163 



increase is in the lower portion, between the Upper Washington and 

 Jollytown limestones, but there is a marked increase in the upper por- 

 tion also. This lower interval, 130 to 140 feet in the deepest area, of 

 Greene county, becomes only 30 feet at the West Virginia line midway 

 in the basin, and the interval. Upper Washington to Nineveh, seems to 

 be about 200 feet thence south-southwestwardly for many miles. 



That the area of deposit was contracting rapidly appears also from 

 the sandstone deposits. The important Fish Creek sandstone is a nota- 

 ble bed in Greene county and extends for a long distance in West Vir- 

 ginia. The Nineveh sandstone, well cemented like the other, is per- 

 sistent from its northern outcrop, in southern Washington county, across 

 Greene into Wetzel of West Virginia, beyond which no information 

 respecting it is available. The Gilmore sandstone, a poorly cemented 

 massive rock, remains on high knobs in Greene county, as well as far 

 southwestward in West Virginia, while the highest rock of the series is 

 a massive sandstone of which only isolated patches remain on knobs 

 in West Virginia. All of these are along the middle line of the basin, 

 where during deposition of all formations prior to the Washington the 

 sandstone intervals were usually filled with shale. The sources of supply 

 were much nearer than in earlier periods. But the basin, though rapidly 

 losing in width, still extended for not less than 200 miles in north- 

 northeast to south-southwest direction when the Nineveh limestone was 

 laid down. 



The limestones, except the Nineveh, are of little importance. No con- 

 clusions respecting the highest limestones can be offered, as those beds 

 remain only on very high knobs and in small patches; yet they are of 

 no little interest, in that they extend southward beyond most of the 

 lower limestones and yield good lime. The Nineveh limestone is per- 

 sistent throughout the whole region in which its place is reached. It has 

 been followed by Doctor White from southern Washington of Pennsyl- 

 vania to Jackson county of West Virginia, about 140 miles, and it is 

 present at localities on the Ohio river, where its place is reached in 

 Tyler of West Virginia and Washington of Ohio. Even at its most 

 southerly exposure it has 30 feet of limestone and calcareous shale. 



No marine forms have been reported from any place. There is much 

 in the character of the Nineveh limestone to lead one to expect such 

 forms, but none has been obtained. Animal remains of all sorts are 

 rare, but Doctor E. P. Whitfield has described some pulmonate forms 

 from Greene beds near Marietta, Ohio, and a few lamellibranchs of 

 doubtful relations have been obtained in Pennsylvania and West Vir- 

 ginia. There is no evidence that the sea actually entered the area in 

 which rocks of the Greene formation remain. 



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