Mesozoic and Cenozoic Geology and Paleontology. 187 
pebbles of the same occur. In some places the coarser and _ finer 
materials are intermingled, in the greatest confusion, and heaped up 
into conical hills thickly scattered over the surface. And again the 
same materials are accumulated in long hills or ridges having a deter- 
minate direction, and sloping down from a high northern elevation to 
the general level of the country south. 
On one hand, we have comparatively an evenly distributed deposit, 
as if made by the retiring waters of an ocean; on the other, the long 
hills, with certain directions, show a determinate course and more 
powerful current in the ocean, while the irregular, conical and dome- 
shaped hills, with deep, bowl-shaped cavities, show the force of con- 
tending currents, or of other obstructions, in the course of the trans- 
ported materials. 
The great bulk of the deposit, whether evenly distributed or irregu- 
larly raised into hills and ridges, is composed of the rock but a short 
distance on the north, or perhaps of the one on which it rests, with a 
constantly decreasing proportion of rocks of northern origin. The 
‘materials of the primary rocks constitute but a comparatively small 
proportion of the superficial accumulations of western New York. The 
local origin of the drift is shown by the sections everywhere examined. 
A section on Irondequoit bay, is as follows: 1. Medina sandstone, 
shaly with bands of green. 2. Fragments and rolled masses of the 
sandstone below, with gravel and sand; this contains a few pebbles 
of the shaly, calcareous sandstone next on the north. 3. Bed of fine 
sand. 4. Stratum of sandstone pebbies, cemented into a conglomer- 
ate by oxide of iron and carbonate of lime. 5. Stratum of pebbles 
and sand. 6. A course deposit of pebbles of the Medina sandstone 
below, with gravel und sand. 7. The soil of sandy loam. An- 
other section 70 miles farther west on the bank of lake Ontario, 
at the town of Wilson, in Niagara county, is as follows: 1. Red 
clay and gravel of the Medina sandstone. 2. Blue clay and gravel. 
The pebbles are principally of the rocks of the Hudson River Group. 
3. Gravel, clay and sand, of the neighboring ‘rocks, folding over 
and passing beneath No, 2. 4. The soil of clayey loam with clay 
below. The sections of the drift almost universally correspond with 
these, and their explanation, viz: a bed of broken fragments, with 
worn pebbles resting upon the rock from which they are derived. The 
granite and other materials of a far northern origin rarely constituting 
apart. And where they do form a part, the deposit may have under- 
gone some subsequent change. 
