. Bulletin of the Geological Society of America. Geology. 206 G. F. WRIGHTâAGE OF DON RIVER GLACIAL DEPOSITS as when laid down. But the water from some unknown cause rose as the accumulation progressed until it was 150 feet higher than now, when the upper sediments of coarser gravel were deposited; then the water began to fall and a period of erosion succeeded. This proceeded until at Scarboro a V-shaped channel, one mile wide at the top and 150 feet deep, was worn in the sedimentary deposits, where- upon the ice advanced again and covered the whole with sheets of boulder- clay and assorted ru
. Bulletin of the Geological Society of America. Geology. 206 G. F. WRIGHTâAGE OF DON RIVER GLACIAL DEPOSITS as when laid down. But the water from some unknown cause rose as the accumulation progressed until it was 150 feet higher than now, when the upper sediments of coarser gravel were deposited; then the water began to fall and a period of erosion succeeded. This proceeded until at Scarboro a V-shaped channel, one mile wide at the top and 150 feet deep, was worn in the sedimentary deposits, where- upon the ice advanced again and covered the whole with sheets of boulder- clay and assorted rubble drift to a total depth of 200 feet. Here certainly seems to be an interglacial deposit of unusual extent. Nor is the character of the fossil plants and animals included in the interglacial deposits any less noteworthy. Both the fauna and the flora of the lower, or Don, beds indicate a much warmer climate than those of JroSuo,s Beach the UPPer' 0r Scar" boro, beds. In the Don beds there are found leaves and wood of maple, elm, ash, hickory, basswood, and even of pawpaw and â scarboro' peaty c/ay^^j^^ osage orange, which (coo/ climatel ^Er^^ nQW flourish only in. Don beds l^-i-^-^"tHk latitudes several de- (warm c/imate) I; c. -_~i~7^_ '." â ' : -H-A&y â =nrbite~sr5b'u/der cia)T~x^°__^ EB5^ ££-ci°^=^ grees south of To- Lorraine shale â : IT^-TIââ\^ ronto ; also, of the mollusks found in the Figure 1.âSection of Don Valley Brickyard, Toronto (Coleman) T Don beds, four of the species are not now found in the Saint Lawrence basin, but only after passing the watershed which separates it from that of the Mississippi. On the other hand, the upper, or Scarboro, sands and clays are wanting in the species indicating a warmer climate, but abound in both a flora and a fauna suggestive of Labrador and of the region north of Lake In the opinion of Professor Coleman, these facts can not be accounted for except on the supposition that the e
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