G3G M. L. FULLER APPALACHIAN OIL FIELD 



STRUCTURE IN WEST VIRGINIA 



The structure in northern AVest Yh-ginia is practicalh' the same as in 

 southwestern Pennsylvania. The Chestnut and Laurel ridge anticlines 

 heconie rapidly weaker to the south, however, although other outlying 

 ridges of considerahle strength take their place. The transition from the 

 sharply folded belt into the more moderately folded and undulating dis- 

 tricts occurs Avithout material faulting. Practically all the pools are 

 associated wdth anticlines (or synclines Avhen water is absent), althougli 

 productive structural terraces exist. 



In southern West Virginia the beginnings of a distinctly different type 

 of structure, which becomes progressively more marked in Kentucky, 

 Tennessee, and Alabama, are seen. The sharp outlying folds west of the 

 Allegheny front are still present, Init instead of grading outward through 

 well defined folds, as in the northern part of the State and in Pennsyl- 

 vania, the beds dip outward (westward) in a comparatively structureless 

 homocline to the center of the basin. The anticlinal warpings are low . 

 and somewha-t poorly defined. 



STRUCTURE IN KENTUCKY 



In Kentucky the change in structure noted in southern West Virginia 

 becomes more marked. The outlying folds of moderate strength are re- 

 placed l)y the stronger folds of the Appalachian Mountain type, the 

 mountainous belt reacliing farther westward and terminating in a faulted 

 front. The beds, which in southern West Virginia dip westward from 

 the disturbed area in a homocline many miles in width, here become first 

 fiat, then dip in a reversed direction, or eastward, toward the sharp fold 

 or fault marking the western face of the mountains. The deepest part 

 of the basin is, therefore, at its extreme eastern edge. The warping of 

 the homocline is very moderate and most of the pools appear to be found 

 on terraces. 



STRUCTURE IN TENNESSEE 



The eastward-dipping homocline of south Kentucky also extends across 

 Tennessee. In this State the western edge of the strongly folded area is 

 everywhere marked by overthrust faults, with the basin beds upturned be- 

 neath them. The basin is deepest along the east edge, except in south 

 Tennessee, where there is an outlying anticline similar to that of Chest- 

 nut Eidge in Pennsylvania, but with much stronger dips and with a fault 

 of considerable magnitude on its west face. This lies about 15 miles west 

 of the normal front of the folded area, which approximately follows the 



