Stevenson.J l^w [Nov. 21, 



The Copper Ridge fault and the Elk Garden anticlinal. 

 The House and Baru synclinal. 

 The Clinch River system of faults. 

 The Stone Mountain anticlinal. 



The Fault of Walker Mountain. 



The Great Valley of Virginia extends in Washington and Smyth coun- 

 ties from Walker mountain south-^astwardly to the limit of those coun- 

 ties. It is underlaid by Cambro-Silurian rocks whose calcareous beds 

 have yielded readily to erosion. The dip is undulating, and one well- 

 marked anticlinal is crossed frequently by the turnpike between Seven- 

 mile ford and Bristol. 



The fault of Walker mountain is clearly the same with that which is 

 termed the South Fork of Holston Upthrow on Prof. Lesley's map of 

 1871. As, however, it nowhere approaches the South fork of Holston, 

 the writer prefers to retain the name applied to it in his memoir of 1881. 

 It is wrongly placed on the map accompanying that memoir, though its 

 position is given rightly in the text as at about four miles from Bristol. 

 The error arose Irom a misunderstanding respecting the true place ot 

 Walker mountain, so that on that map, this fault occupies very nearly the 

 place of the Saltville fault. 



This fauh, in much of Washington county, brings the Trenton lime- 

 stone into contact with the lower part of the Knox group. Where it is 

 crossed between Bristol and Mendota cannot be determined accurately 

 without detailed study, but the course is shown approximately by a 

 rather low ragged ridge of limestone which can be followed without 

 difficulty to the eastern edge of Washington county. The line of fault 

 is crossed by the Saltville branch of the Norfolk and Western Railroad 

 at the water station, somewhat less than two miles from Glade spring. 

 Thence the downthrow rapidly increases, and within two miles the 

 ragged ridge of limestone becomes Walker mountain with Medina and 

 Clinton, the fault line passing just north from Washington springs. 

 The downthrow continues to deepen, Devonian is held on the northerly 

 side of the fault, and the mountain is divided into Big and Little 

 Walker, Medina and Chemung ridges, separated by a valley of Clin- 

 ton and Hamilton. This structure is well shown on Chilhowie creek, 

 though at the place of the fault, nearly three miles north from the rail- 

 road, everylliing is wholly concealed. It is altogether probable that the 

 lowest beds of the Lower Carboniferous are held on the north side of the 

 fault toward the eastern edge of Smyth county, for in the adjoining county 

 of Wythe Vespertine coal beds occur and they have been worked. Unfor- 

 tunatel}' one cannot determine with equal ease the changes which take 

 place on the southerly or upthrow side of the fault ; the Knox limestones 

 have yielded to erosion and solution and for the most part their surface is 

 deeply buried under debris. There is no room for doubt, however, that 



