72 DK. E. HULL ON THE THYSICAL GEOLOGY OF 



tree-frogs. Prom the crest of the escarpment at various points 

 beautiful and extensive prosj)Ccts may be obtained of this region of 

 wooded plateaux and wide valleys, where the white man has as yet 

 done little to alter the natural landscape, or to diminish the extent 

 of the primaeval forest *. 



3. The Sequachee Valley. — The table-land thus described is inter- 

 sected longitudinally by a remarkable valley, that of the Sequachee 

 lliver, for a distance of sixty miles, in a nearly straight line north- 

 eastward from the banks of the Tennessee near Jasper, with an 

 average breadth of four miles. The narrow plateau thus formed be- 

 tween the valle}^ of East Tennessee and the Sequachee is known as 

 "Walden's Uidge " (see Map, fig. 1). The direction of the Sequachee 

 Valley is therefore parallel to that of the eastern boundary-scarp of 

 the table-land itself, where it overlooks the Valley of East Tennessee. 

 On either side it is bounded by steep and densely-wooded slopes, 

 generally crowned by cliffs of grit or conglomerate ; and at its upper 

 end the Sequachee lliver has its origin in copious springs issuing 

 forth at the foot of the sandstone cliffs. 



I was unable to visit the source of this stream, but, from the 

 accounts I had from observers in the district, it must be most 

 remarkable. Erom the foot of the cliff the waters flow down the 

 steep slopes into a natural caldron, formed in the soft shales and 

 grits overlying the Carboniferous Limestone. The latter here forms 

 a barrier, holding back the waters which have hollowed out a tunnel 

 through the rock, and on issuing forth they descend into the valley 

 in a series of cascades. 



The flanks of the Sequachee Valley are composed of Carboniferous 

 grits and shales resting on limestone, from below which the Devonian 

 and Silurian strata emerge with a dip in the direction of the sides of 

 the valley (see figs. 2 and 3). The valley is therefore clearly in the 

 line of an anticlinal axis ; and to this it probably owes its origin, 

 though it is possible that there may be a fault here running in a 

 parallel direction, along which river-erosion has acted through a 

 lengthened period. It is a striking example of valleys of this kind. 

 The Little Sequachee, a smaller valley further to the west, is prob- 

 ably due to a similar anticlinal flexure. 



4. Rochs of the Cumberland Table-land. — The geological structure 

 of the Cumberland Table-land is extremely simple. The strata of 

 which it is formed consist of grits (sometimes pebbly), sandstones, 

 and shale, with beds of coal, all of Carboniferous age, resting on 

 Mountain-Limestone, which crops out in two beds, separated by 

 soft red sandstone, all along the base of the escarpment ; the two 

 series constitute in part the " Carboniferous " and " Sub-Carboni- 

 ferous " groups of American geologists (see figs. 2 and 3). 



The Carboniferous series is succeeded, in descending order, by 

 dark Devonian shales, which, owing to their friable nature, have 



* This region v^^s the abode of Cherokee Indians, who some years ago were 

 transplanted to the Indian Reserves in the Western States. Shell-monnd 

 Station is the site of the terrible slaughter of this tribe by its white and more 

 civilized brethren in 1816, under Major Bond. 



