STRUCTURAL FEATURES OF SPECIAL LOCALITIES. 183 



the character of the sediments deposited in these basins, and this is 

 especially true when we know so little of their source and the attitude of 

 the land surface from whence they were derived. In the opinion of the 

 writer the evidence favoring an overlap vastly overbalances the negative 

 evidence derived from the sedimentation. 



Ingles and Berringer Mountains. — These mountains have a structure 

 and history similar to Price mountain. Like it, they are surrounded by 

 the Shenandoah limestone, or rather rest upon it unconformably, for 

 their measures are entirely of Devonian age, and the interval must repre- 

 sent a great time-break. 



Ingles mountain is a small double ridge south of Radford and on the 

 south side and parallel to the old " Rock road." It is composed of a 

 sandstone which appears to be interbedded with the Walker black shales 

 and presents the same evidence of overlap as does Price mountain- 

 It has been lifted into an anticline in the same manner, and now the 

 crown of the arch is cut through, leaving two nearly j^arallel ridges of 

 sandstone, dipping moderatel}^ away from the axis in either direction. 

 At their western extremity, on the bank of New river, these two unite 

 around the end of the anticline and make a conspicuous showing in the 

 cliffs of the river. The sediments in this sup})osed basin correspond 

 much better with our ideas of shore deposits, for the sandstone forming 

 Ingles mountain is heavier near Xew river and apjDarently thins eastward 

 to but a few feet in a distance of five miles, and presumably in the direc- 

 tion of the open sea. East of Ingles mountain the " Rock road " crosses 

 this belt of Walker black shale, leaving the main mass on the northern 

 side of the road. 



Berringer mountain is formed by the Kimberling shales, which come 

 in on the northern side of the area. Its eastern termination was not 

 worked out ; so that at present it is impossible to state definitely whether 

 the line of contact along the northern face of Berringer mountain is a 

 fault or a line of overlap, but it appears to be a fault. 



Cambrian Area at Peppers Ferry. — Between Price and Berringer moun- 

 tains the limestone is greatly disturbed, and several areas of Cambrian 

 (Graysonton) shale occur. One of these areas was found along New 

 river just above Peppers ferry, five miles below Radford. This was 

 not examined thoroughly, but the contact on the south between the pur- 

 ple shales and the Shenandoah is thought to be a normal boundary, 

 while on the northern side of the area there are some heavy quartzites 

 in direct contact with the limestone. Whether this is an overlap) or a 

 fault could not be determined. An interesting fact in connection with 

 this Cambrian area is the great amount of limestone conglomerate to be 

 found in its immediate vicinity ; especially on its northern side the con- 



