312 
The American Geologist. xovembeiMooi. 
Subsequcntlv a snowy climate again caused an ice-sheet 
to overspread this area, with repeated oscillations of its bor- 
der. The oncoming- and wavering of this glaciation, shown 
by its drift series, have also been described by Coleman as 
follows : 
The halt at the Scarboro' delta was long, and must have included at 
least three great osci'llations of retreat and advance, to account for the 
complex of tills separated by stratified materials now crowning the 
hights. The first sheet of till is shov/n for about nine miles continuously 
at Scarboro' with the shape of a slightly bent bow, touching the lake 
at each end, and with a sharp downward dip at the Dutch church. The 
latter is however, less symmetrically placed than in a bow, being only 
three miles from the west end and six from the east. The hollow of 
the Dutch church valley was filled with till containing comparatively 
few stones to a level 50 or 60 feet above the present lake, then merging 
into gray stratified clay which rises to a hight of 165 feet, where it is 
covered with a few feet of much later Iroquois beach gravel. Very sim- 
ilar clays rising to the same hight, or a little higher, are found at brick- 
yards to the north of Toronto. They burn to a gray brick, and so are 
easily distinguished from the peaty clay which makes red brick. 
The highest part of the Scarboro' escarpment, about a mile east of 
the Dutch church, gives the best section of these complex glacial de- 
posits. At the point where the old Iroquois beach is cut off for a dis- 
tance by the present lake cliff, there is a face of 270 feet displaying 
three layers of boulder clay separated by stratified sand, the whole 
overlying the stratified fossiliferous sands of the Toronto formation. 
A few hundred yards to the east of this the escarpment reaches its 
highest level, 354 feet above the lake, but the lower part is not so 
well shown. The upper portion is, however, more complete, since over- 
lying the third till sheet one finds laminated grayish blue or purplish 
clay followed by evenly bedded fine sand, on which rests a fourth 
boulder clay. Putting the two sections together, we have the follow- 
ing complete section : 
FEET. 
Boulder clay, No 4 48-354 1 
Stratified sand overlying | • ■ 
stratified clay 36-306 j 
Boulder clay, No. 3 32-270 | 
Silty sand, the upper layers } 203 feet, Glacial complex. 
crumpled 25-238 j 
Boulder clav. No. 2 . 9-213 | 
Cross bedded sand 29-204 | 
Boulder clay. No. i 24-175 j 
FossiHferous sand 59-I5I 1 ^r-, fgeli Toronto forma- 
Peaty clay 92-92 ^ ti^^^ 
Lake Ontario o | 
No fossils have been found in the sands or clays of the glacial 
complex at Scarboro', but a few have been picked up in stratified sand 
lying between two beds of boulder clay at the Metropolitan power 
