278 W. M. Fontaine— Conglomerate Series of West Virginia. 



may be traced far to the southwest, and probably to the north, 

 and is to be explained by the existence of a fault, apparently 

 the most westerly of the system affecting the Appalachian 

 Region in this quarter. The development of this fault seems 

 to have, in a great measure, relieved the strata lying to the 

 west, from the disturbing force which so highly affected them 

 on the east and it is not necessary to suppose a gradual dying 

 away to the westward of the lateral thrust from the east. The 

 conditions seem to imply a certain amount of unconformability 

 between the Devonian and Vespertine, which is not incompati- 

 ble with other facts observed here. 



Proceeding westward along the line of the railroad from the 

 fault, the gentle rise of the Vespertine to the west brings into 

 view its middle or coal-bearing portion, here also containing 

 small coal seams. This is in the vicinity of the bridge over 

 Greenbrier Eiver, and explains the presence near this stream, 

 of the coal seam mentioned by Prof. Wra. B. Rogers in his 

 reports. The Vespertine as it crosses the stream passes into a 

 low anticlinal, which, west of the river, finally brings down the 

 Umbral limestone to the level of the railroad. This position it 

 maintains for a long distance, as far as Great Bend Tunnel, 

 near the mouth of the Hungert's Creek, Summers County, where 

 it dips under the red rocks of the Umbral series, which in this 

 district are greatly developed. The Umbral series seems to pos- 

 sess a threefold character, being at bottom blood-red shales and 

 sandstones, in the middle, grayish, bluish and brownish sand- 

 stones and shales, mainly the former ; and at top brownish 

 sandstones, blood red and varigated shales. The shales through- 

 out the series have the texture of marlites, and the sandstones, 

 although chiefly argillaceous are sometimes liighly sibceous, 

 forming huge cliflfs along the railroad, as seen near Richmond 

 Falls. These three series, the Vespertine, the Umbral limestone, 

 and Umbral shales and sandstone, thicken rapidly in proceeding 

 from northeast to southwest. Prof Rogers measured them m 

 Greenbrier Mountain, Pocahontas County, a point about sixty 

 miles northeast of Richmond Falls on New River, where_the 

 Umbral shales and sandstones are extensively exposed. With 

 respect to the limestone I have no data for comparison but the 

 indications are that on the railroad it is thicker than the measure- 

 ment given by Prof. Rogers, viz : 822 feet. For the ^^nibral 

 shales and sandstones in Pocahontas he gives a thickness of 1.6W 

 feet. My estimates along the line of the railroad, which, however, 

 have not the accuracy of measurements, give for this series a 

 probable thickness of 1,450 feet in the vicinity of Richmond 

 Falls, distributed as follows: 1. Lower red shales and sand- 

 stones, 320 feet; 2. Middle gray and greenish sandstones, 8-U 

 feet; 3. Upper red and variegated shales, 310 feet If we com- 



