SECOND ANNUAL REPORT—-STRATIGRAPHIC GEOLOGY. 
143 
upon the question. For this reason, the matter should be left for subse¬ 
quent investigation. 
Thickness:—Though widely distributed, the Lafayette formation is 
comparatively thin, seldom exceeding 30-60 feet, and having perhaps an 
average thickness of less than 50 feet. 
Physiographic Expression:—The Lafayette has undergone exten¬ 
sive erosion since its deposition, and so much of the original material 
has been re-worked and re-deposited under varying conditions and in 
different physiographic positions that it is now difficult to determine 
which deposits were original and which are to be classed as the second¬ 
ary products from the erosion of the original. However, considered 
from a broad physiographic standpoint, there are a series of more or 
less flat-topped hills and dissected table lands, in the northern part of 
the State, which can best be explained as remnants of a more extensive 
deposit which was formed when the region was one of low relief. It 
is difficult to make any close correlation between the separate remnants 
of this upland because the amount of erosion which they have suffered 
since deposition has varied greatly, and, furthermore, if the formation is 
non-marine, close accordance in altitude is not to be expected, because 
the surface of such a deposit would probably not be even, but would 
vary slightly from place to place. The general range in altitude for 
this tableland is approximately 50 feet, and there is a gradual increase 
from about 250 feet above sea level at the southern margin of the up¬ 
land to nearly 300 feet above the same datum plane along the northern 
boundary of the State. 
Paleontologic Characters:—The Lafayette formation is not known 
to contain fossils of marine organisms, except such as have been derived 
from the erosion of older strata. Remains of land and fresh water 
fossils have been found outside the state; but no fossils of any sort have 
been reported from this formation in Florida, and since the beds are 
well exposed, it appears safe to say that it does not contain many. 
Structure:—The Lafayette formation shows no structural features 
of interest, though it may have been subjected to the same deformation 
which produced the gentle arching of the marine Pliocene beds. 
Local Details:—The Lafayette formation occupies a belt about 40 
miles in wddth, extending from near the Suwanee River westward to 
Escambia County. Some large tracts are found in Gadsden, Leon and 
Jefferson Counties on the east side of the Apalachicola River; and in 
Holmes, Walton, Santa Rosa and Escambia Counties in West Florida. 
This formation is typically developed in the upland of the counties along 
the north line of the State, but good exposures are rare. The red sands 
of the counties mentioned are largely assigned to the Lafayette forma¬ 
tion, though the accuracy of this correlation is sometimes doubtful, be¬ 
cause of the absence of fossils. The selection of typical sections of the 
