. Biological series. Biology. 68 Glacial and Post-glacl\l Lakes in Ontario their cour-e in from 20,0(i0 to 35,000 or possibiy 39,000 years. Mow i^ the tinif: lo l>e di\-if]erl amoni,^ them? Two of these !)odic.^ of water, Lake Iroquois and Lake Ontario, were much alike in area and have Ix-achcs of about the same maturity. The work performed on their shores shows that botli must have been long Hved; the intervening stages, inclu(Jing the marine episode, are represented by much less perfectly formed beaches, sug- gesting a shorter time for v/ave action. It should be added, however, tha
. Biological series. Biology. 68 Glacial and Post-glacl\l Lakes in Ontario their cour-e in from 20,0(i0 to 35,000 or possibiy 39,000 years. Mow i^ the tinif: lo l>e di\-if]erl amoni,^ them? Two of these !)odic.^ of water, Lake Iroquois and Lake Ontario, were much alike in area and have Ix-achcs of about the same maturity. The work performed on their shores shows that botli must have been long Hved; the intervening stages, inclu(Jing the marine episode, are represented by much less perfectly formed beaches, sug- gesting a shorter time for v/ave action. It should be added, however, that the shores of Admiralty lake, whirl: came just before the marine inva-ion. probably mostlv .~ub- merged under Lake Ontario and so out of reach. Lake Ontario is still at work and it is iK>ssibie to measure the results of its wa\e action. For this purpose the recession of the cliffs of glacial and interglacial deposits at Scart>orough Heights east of Toronto is well suited. The first accurate sur\-ey of Scarborough was made in LSG2 and the distance of the cliffs from seventeen fixed points was remeasured in 1912. Some of these lines came out at ravines which 15. Map of Silure and Island at Toronto. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original University of Toronto; Toronto, Ont. University. University of Toronto studies. Biological series. Toronto University Press [etc. ]
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectbiology, bookyear1898
