186 M. R. CAMPBELL — PALEOZOIC OVERLAPS IN VIRGINIA. 



hilly region just south of Max Meadows, where the core of the arch is 

 composed of the Kimberling shale. West of Hamilton knob the Price 

 sandstone comes in on the southern side of this anticline, forming a 

 curious cross-ridge of quartzite running from near Hamilton knob to 

 Max Meadows. This anticline is completely bordered by Shenandoah 

 limestone from west of Hamilton knob around through Max Meadows 

 and eastward to Clarks summit, which is the easternmost extension of 

 the limestone. This boundar}^ has many features common to the lines 

 of unconformity already described, so that it is regarded as a line of 

 overlap, but near Max Meadows it also shows considerable disturbance, 

 which indicates movement along the plane of juncture. 



Relation of Shenandoah Limestone to Devonian Shales on Hamilton 

 Knob. — In the vicinity of Hamilton knob there are some isolated out- 

 crops of limestone that probably afford more positive evidence of the 

 unconformable deposition of the Devonian and -Carboniferous sediments 

 upon an irregular surface of the Shenandoah limestone than any other 

 yet found. 



A few years since, when the great wave of mineral development swept 

 over the South, a company was organized to develop the deposit of iron 

 ore that accompanies this interesting exposure of limestone. A furnace 

 and rolling mill were built at Max Meadows, a narrow-gauge road con- 

 structed across the Devonian hills to this locality, extensive washers 

 erected and mining begun on quite an extensive scale. Unluckily the 

 deposit was found to be of quite a limited extent and the ore lean, so 

 that the boom soon collapsed without accomplishing anything in a com- 

 mercial way, except sinking a large amount of money. The excavations 

 made in their search for ore have proved of great value to the geologist, 

 for they afford him exposures of rock and contact phenomena that 

 otherwise would have been impossible to obtain. 



This area of limestone, marked Z on the map, is located on the brushy 

 spurs of Hamilton knob probably 200 feet above the stream draining 

 the area. A north and south section through this exposure shows a 

 normal condition of the country rocks that is an exact counterpart of 

 the section further west where the creek cuts the outer ridge. North of 

 the limestone is the slightly disturbed sandy shales belonging to the 

 upper Devonian, while on its southern side and directly in contact is 

 a characteristic dark fissile shale, slightly fossiliferous, agreeing with a 

 similar shale that shows in the gap of the ridge west of the limestone 

 and lies just below the heavy Price sandstone. In the ore banks at the 

 limestone outcrop these shales are considerably crushed and disturbed, 

 and a little higher on the slopes of Hamilton knob the heavy Price sand- 



