324 
GEOLOGY OF THE FOURTH DISTRICT. 
There appear to have been several periods of deposition, where the laminae do not coincide, 
and which are separated by stronger lines of division. The section is a perfect representation 
of the face of the hill: nearly all the strata dip towards the west, and the accumulation doubt¬ 
less took place from this direction, from the heaping of the coarse gravel upon the fine sand. 
The gravel consists principally of waterworn fragments of the Niagara limestone, on which 
the whole deposit rests, and of the sandstones and limestones on the north. There are some 
boulders of the limestone, from two to four feet in diameter, worn perfectly smooth, or often 
striated with shallow grooves; and from the fact that this is the subjacent rock, they have 
received their rounded forms and smooth surfaces from attrition near the spot where we now 
find them. 
This character of the hills of the northern range of counties could be illustrated by nu¬ 
merous sections, showing the diagonal lamination, removal and re-deposition of deposits. 
Scarcely a hill can be excavated, where this kind of structure is not observed in a greater or 
less degree, and sometimes the whole deposit is in such confusion as to present no definable 
structure. 
In the southern counties, after leaving the deeper valleys, the superficial detritus is less, 
and differs in character from that in some of the more northern parts of the district. Its con¬ 
nection with the stratified rocks below is the same, and resting upon them we find an ac¬ 
cumulation of fragments of variable dimensions, mixed with clay, gravel and rounded pebbles. 
The materials, however, bear less evidence of attrition than those farther north, and there are 
but few rounded pebbles. The “flat gravel” of the hills, and the “round gravel” of the deep 
valleys, has before been noticed. These terms serve to distinguish different degrees of attri¬ 
tion, as well as marking different portions of country. The origin of the mass is the same as 
in the northern part of the district, but it has been less subjected to subsequent operations, and 
may be regarded as presenting the primitive state of drift, or diluvium. It must be recollected 
also that in all these situations there are no primary boulders intermingled with the mass, 
though they are occasionally seen upon the surface. The materials of the northern stratified 
rocks of the district appear never to have been lifted to this elevated portion of the country, 
and are found only in the lower valleys. 
I may here remark, that these investigations were commenced with a belief in certain views 
and theories regarding the production of drift; but as my observations progressed, the diffi¬ 
culty of reconciling the facts with these preconceived notions became constantly more apparent. 
In conclusion, therefore, although some of the foregoing arguments may not appear quite 
satisfactory, or free from doubt, it must be remembered that long continued and extensive 
examinations are necessary to put us in possession of all the facts bearing upon the subject, 
while comparatively little time could be devoted to this department; and I have been unable 
to revisit localities, where, two, three, and even four years ago I noted circumstances and 
appearances, which at present, with the different views to which I have been led by multiplied 
observations, coincide with and confirm these inferences. 
The theory usually inculcated in regard to the great body of drift covering the surface of 
the strata, is that it consists of granite and other materials of far northern origin, which have 
