PERIODS OP APPALACHIAN FOLDING. 



189 



(Z) FOLDING 



I 



O 



(D; FOLDING 



Summary. 



In conclusion, the results of this work may be briefly stated to consist 

 of the determination of the existence of a land-surface in this portion of 

 the valley, from the beginning of the Devonian up to the time of the 

 deposition of the Carboniferous limestone. This necessarily involves 

 two periods of disturbance ; one folded the lime- 

 stones and produced the basins in which depo- 

 sition took place, the other elevated these basins 

 and brought to a close the period of sedimenta- 

 tion, and also probably folded the strata into 

 the form it shows today. 



The establishment of these two periods of dis- 

 turbance is the important fact which, taken in 

 connection with other well established periods 

 of overlaps, shows a somewhat regular distribu- 

 tion of these disturbances throughout Paleozoic 



time. 



The earliest j^eriod known, indicated by A in 



figure 1, is that which occurred in lower Cam- 

 brian time, and is represented by the overlap of 

 Chilhowee mountain.* This folding, so far as 

 known, is limited to a narrow zone on the south- 

 eastern side of the valley, and is probably repre- 

 sented in this vicinity by unconformities in Lick 

 mountain, a few miles west of Max Meadows. 



The next well known period of disturbance, 

 marked B, occurs near the top of the Shenan- 

 doah limestone, and it has been referred to in 

 this paper as being characterized by limestone 

 conglomerate throughout a wide area, and par- 

 ticularly so on Stony creek, Giles county. Lime- 

 stone conglomerates at or near this horizon are figure i.-Determined Periods of 

 known all along the eastern edge of the valley Appalachian Folding. 



across Tennessee, but have never been described. General stratigraphic column 



. 1.11 1 J. ± J.^ ' showing their approximate Po- 



In Georgia and Alabama a conglomerate at this sjtions and roughly indicating 



horizon covers a large extent of country and has their occurrence in Paleozoic 



been briefly described by C. W. Hayes.f ^"^^' 



The main period of deformation, marked C, treated of in this paper is 

 the one which folded the limestones and produced the structural basins 



I 





^ 



5 



*, 

 ^ 



-(C) FOLDING 



(B) FOLDING 



(A> FOLDING 



*Phil. Soc. of Washington, Bu'l., vol. xii, pp. 77-88. Arthnr Keith : Geology of Chilhowee Moun- 

 tain in Tennessee. 



tGeological Survey of Alabama, Bull. no. 4. Report on the Geology of Noi'theastern Alabama 

 and adjacent portions of Georgia and Tennessee, pp. 42-43. 



