42 TRANSACTIONS OF THE [Dezc. 5 
extension of the Great Lakes many of these clays were deposited. 
They contain in many instances limestone pebbles. A thin layer 
of yellow sand, suitable for tempering, often overlies the clay 
around Buffalo, 
An extensive bed of clay of a red and grey color and horizon- 
tally stratified occurs at Watertown. It is one of the few of 
which an analysis has been made, and it is here given. 
SiOz “| : : : 64.39 
Al,O3_.. : : : 14.40 
Fe.03 ; 5.00 
H20 and Org. Matter ; 6.64 
CaO : : 3.60 
MeOn = : : F 1.31 
Alkalies : : : 4.66 
100.00 
The bank is some twenty feet thick and rests on Trenton 
limestone. 
A deposit of considerable thickness occurs at Ogdensburgh. 
The clay is of a blueish color, the upper ten feet being some- 
what sandy. A depth of 60 feet of clay has been proven, At 
places it is found to be underlain by limestone. 
At Madrid, in St. Lawrence county, isa small deposit, proba- 
bly the remnant of a formerly extensive one, in which the sec- 
tion is, 
Yellow stratified sand ‘ ; : 3 feet. 
Blue clay with shells : : : 1 foot. 
Blue clay : : : : . 20 feet. 
Total thickness . F . 24 feet. 
The shells are probably Mucoma Per 
The clay beds along Lake Champlain are estuary formations 
of the same age as those along the Hudson Valley. Openings 
have been made in them at Plattsburg, Essex, and a few other 
localities, but owing to the lateness of the season when I visited 
them information was hard to obtain, 
Clays of the Mohawk and Hudson River Watershed. 
Deposits of common brick clay are found at many points along 
the line of the New York Central Railroad from Syracuse to 
Schenectady. They are used at many points for the manufac- 
ture of brick and tile. 
Very interesting are the Hudson River clays. They are estu- 
ary deposits and extend from Croton more or less continuously 
up the Hudson Valley to Glens Falls and westward to Schenec- 
tady. These clays were deposited during a post-glacial sub- 
