70 
The American Geologist. 
February, 1901. 
of the limestone. The first merits special description, the 
gorge being confined to it. 
Fig. 1. 1 Quartz schist; 2 Biotite schist; 3 Limestone; A Tallulah river ; B 
Chattooga river; C Tugaloo river; D Panther's creek. 
This quartz schist, as far as mapped, exhibits an unusually 
well developed joint structure one of whose planes corre- 
sponds closely with the schistosity dip which is about 25° in 
a direction south 20° west. 
If this schist was derived from pre-existing sedimentary 
rocks, as seems probable, the strike of the true bedding planes, 
which have since been obliterated in the perhaps several times 
repeated mctamorphism of the region, must have corre^ 
sponded with that of the limestone belt which, as can be seen 
from the map, makes a large angle with the schistosity strike. 
The course of the Tallulah, and indeed of all the streams 
in the region under consideration, seems to show no evidence 
of close adjustment between the flow of the rivers and the dip 
and strike of the rocks. 
Figures i and 2, plate IX. show very well the joint struc- 
ture mentioned above and the relation of the river to the 
rock. 
