OF THE APPALACHIAN CHAIN. 



489 



the great fault, which extends along the southeastern base of 

 the Little North or Brushy mountain, hereafter to be more partic- 

 ularly noticed. 



7. Holston Division. In this region, the folded structure, at- 

 taining its maximum limits, assumes the new condition, (evinced, 

 in a few cases, in the preceding district,) wherein the inverted 

 flexures become a series of dislocations, surpassing, for their 

 length, straightness, and parallelism, any other group of faults 

 recorded. By far the greater part of the strata dip in one direc- 

 tion, or to the south-southeast, the downthrow at the faults being 

 invariably on their northwest side. In crossing this region to the 

 north-northwest, after passing for some distance to older and older 

 formations as we approach a line of elevation, instead of meeting 

 with their counterparts, in an anticlinal arrangement, we step, at 

 once from some of the oldest of the Appalachian formations, to 

 beds as recent as the European carboniferous limestone, and thus 

 behold in near contact, on opposite sides of the closed gulf, strata, 

 which originally occupied positions in the vertical column, eight 

 thousand feet apart. This abrupt transition may be noticed, many 

 times in succession, in the first thirty miles, going northwestward 

 from the base of the Blue ridge. 



8. Knoxville Division. As in the instance of the district last 

 described, the whole disturbed space is comparatively narrow. 

 Here, too, in consequence of the numerous inverted flexures and 

 parallel lines of dislocation, the strata are extensively inverted, 

 having, therefore, very generally, a dip to the southeast, and dis- 

 playing the normal form of flexm-e but rarely, until we reach the 

 northwestern side of the district. Of this universal prevalence of 

 southeasterly dip, mention is made by Professor Troost, in his 

 ' Annual Reports on the Geological Survey of Tennessee, for the 

 years 1S39 and 1840,' and we can confirm his statements by our 

 own observations, made in the northern parts of the district. An 

 interesting feature in this belt, is the analogy which it displays to 

 the other convex, or Juniata division, in the regular or uninter- 

 rupted curving of the axes and lines of strike ; and, on the other 

 hand, the decided contrast, in this respect, which they both pre- 



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