a3 
tertiary deposit of considerable’ thickness, consisting of ‘slaty clays, 
quartzose sand, loam of a brick-red colour, and beds of siliceous burr- 
stone. Mr. Lyell is not aware of any published description of this 
formation, though he afterwards met with it on the Savannah: river. 
In both localities some of the clays break with a conchoidul flinty 
fracture when dry, and even occasionally pass into a stone closely re- 
sembling menilite. The fossils which he found were in the state of 
casts. He does not determine whether this formation should be re- 
garded as an upper division of the eocene group or not ; but he has 
little doubt that it is of the ‘same age as the burr-stone: series of 
Georgia, In the notice of the cretaceous and tertiary strata of the 
Southern states, drawn up by Dr. Morton from the notes of Mr. Va- 
nuxem, the tertiary limestone and the burr-stone sand and clay are 
included in the same group, and Mr. Vanuxem informed Mr. Lyell 
that he had not been able to determine their relative position ; but 
from what Mr. Lyell saw on the Savannah river, he infers that the 
burr-stone formation is above the limestone. One of the strata at 
Stoudenmire is extremely light and of white colour and resembles 
calcareous tufa, but according to the analysis of Prof. Shepard it con- 
tains no carbonate of lime; Mr. Lyell, therefore, states it may pro- 
bably be of infusorial origin. , 
At Aikin, sixty miles west of Orangeburg, and near. the left bank 
of the Savannah, an inclined plane ina railway has been cut through 
strata 160 feet in thickness, consisting of earth and sand of a vermi- 
lion colour and containing much oxide of iron ; also of mottled clays 
and white quartzose sand with masses of pure white kaolin. These 
strata are within ten miles of the junction of the tertiary formation 
and the great hypogene region of the Appalachian or Alleghany 
chain, and their materials, Mr. Lyell states, have evidently been de- 
rived from the decomposition of clay-slate and granitic rocks... No 
fossils were observed by him in the deposit at) Aikin. A similar for- 
mation is extensively developed at Augusta, where the Savannah di- 
vides the states of South Carolina and Georgia, and it must, in some 
places, be more than 200 feet thick. Three miles above the town are 
the rapids, which descend over highly inclined clay-slate and chlorite 
schist, overlaid unconformably by tertiary beds. ‘This point is the west- 
ern boundary of the supracretaceous series; and Mr. Lyell observes, 
that/on all the great rivers of the Atlantic border from Maryland to 
Georgia, and still further south, the first falls ov rapids are along aline 
at which the granitic and hypogene rocks meet:the tertiary, and which 
isnearly parallel to the Atlantic coast, but.at the distance of 100 or 150 
geographical miles.» This great feature, Mr. Lyell states, was first 
pointed out by Maclure, but hevadds that portions of the tertiary 
formations usually cover the hypogene rocks for a certain distance 
above the Falls, and that their outline is very irregular and )sinuous. 
On Race’s Creek near Augusta, the highly inclined clay slate, con- 
taining chloritic quartzose beds with subordinate strata much charged 
with iron, are decomposed to the depth of many yards into clays and 
sands which resemble so precisely a large portion of the horizontal 
tertiary strata of the neighbouring country, that the disintegrated ma- 
