240 The American Geologist. April, i899 
NOTES ON THE CRETACEOUS AND ASSOCI- 
ATED CLAYS OF MIDDLE GEORGIA.* 
By George E. Ladd, Rolla, Mo. 
The state of Georgia is well supplied with a large variety 
of interesting and economically important clays. None of 
these are more worthy of investigation, as regards both their 
geological occurrence and their physical properties, than those 
which are found traversing the central part of the state in the 
immediate vicinity of the "fall line." 
This line, which is practically the boundary between the 
rocks of the Piedmont plateau and the stratified deposits of the 
coastal plain, traverses the central part of the state in a gener- 
ally east and west direction and passes through the cities of 
Augusta, Macon, and Columbus. 
Journeying across the state from one of these cities to the 
other by rail, or over the dirt roads, the fall line is crossed and 
recrossed many times, and the observer recognizes here the 
features of the Piedmont plateau, and there those of the coastal 
plain. On the Piedmont side appear the well rounded hills and 
deep red soils which characterize its ancient formations. Oc- 
casionally, and especially in the vicinity of streams, are bare 
stretches of crystalline rocks, while frequently in the gullies 
and road-way cuts various transitions are exposed between 
the fresh crystalline rocks and the products of its decomposi- 
tion which constitute the soils. The schists are brilliantly col- 
ored, especially where decomposed, yellow and green shades 
predominating. The soil above the crystallines is compara- 
tively fertile and yields abundant crops. 
On the coastal plain where the highest elevation is about 
seven hundred and fifty feet, the well defined hills of the Pied- 
mont belt are" replaced by broad flat-topped plateaus and wide 
reaching terraces, the latter particularly predominating in the 
vicinity of the great rivers. 
Occasionally streams and railroad cuts penetrate through 
the sedimentary strata to the crystalline rocks below, and it 
is often hard to distinguish where the one ends and the other 
begins, the lowest of the sediments being composed of the 
coarser elements of the underlying crystallines, large boulders 
of which frequently occur in the sedimentary beds. 
*Published with the permission of the" State Geologist of Georgia. 
