184 M. R. CAMPBELL PALEOZOIC OVERLAPS IN VIRGINIA. 



glomerate is very heavy, forming a cliff just below Peppers ferry forty 

 or fifty feet high. The key to this structure will probably be found along 

 the railroad in the direction of Christiansburg, where the structure is 

 evidently quite complex. 



Syndine of Sevier Shale south of Radford. — South of Ingles mountain 

 there is a shallow syncline of Sevier shale lying perfectly conformable 

 to the limestones beneath. The presence of this remnant of shale does 

 not make it positive that the formation was originally deposited over 

 this entire region and then eroded before the later overlaps occurred- 

 True this would be the natural and reasonable supposition if it were not 

 for the presence of a conglomerate near the top of the Shenandoah lime- 

 stone. This occurs in many places between this area and the edge of the 

 great Carboniferous formations on the northwestern side of the valley. 

 Near Pearisburg, in Giles county, this conglomerate is finely exposed in 

 the bed of Stony creek, showing the regularly bedded limestone alter- 

 nating with beds of heavy conglomerate. This conglomerate has a 

 calcareous matrix and pebbles of sandstone, quartzite, vein quartz and 

 chert, some of which are four inches in diameter and generally flat and 

 well worn. This certainly points to shore conditions near this locality ; 

 but the conglomeratic phase is widespread, and would seem to indicate 

 numerous shorelines, possibly an archipelago with structural islands of 

 limestone, from which the cherty material was obtained. If such condi- 

 tions as this prevailed on the northern side of the great Appalachian 

 valley, it certainly is not unreasonable to suppose that similar processes 

 were going on here, and that this small area of Sevier shale may be but 

 a deposit in a narrow structural basin and no contemporaneous deposit 

 occurred over the limestone areas adjacent. 



Pidaski-Max Meadoivs Area: Overlap north of Pulaski. — From Rad- 

 ford to Pulaski no trace of this peculiar structure could be found. The 

 country is entirely limestone, still badly contorted. In the vicinity 

 of Pulaski there are well shown the same structural features which 

 have already been described in Price mountain. Northwest of Pu- 

 laski there is an anticline whose axis trends approximately east and 

 west, and which, as it extends westward, brings up successively lower 

 and lower formations. North of Wytheville the lowest formation ex- 

 posed is the Sevier shale, while at the Wythe-Pulaski line the Kimberling 

 shale is the lowest member. This formation forms a point about three 

 miles northwest of Pulaski, and the Price sandstone encircles this point 

 with a range of knobs called the Peak hills.' These hills are cut off near 

 the Altoona coal mine by the Walker Mountain fault, but they are 

 in contact with the same sandstones of Little Walker or Brushy moun- 

 tain. Around the margin of this formation the Pulaski red shales are 



