No. 4.] SPENCER — SURFACE GEOLOGY. 213 



SURFACE GEOLOGY OF THE REGION ABOUT THE 

 WESTERN END OF LAKE ONTARIO. 



By J. W. Spencer, B.A.Sc, M.A., Ph.D., F.G.S., 

 Vice-President of the University of King's College, Windsor, Nova Scotia. 



(This Paper is Part II. of the <' Geology of the Region About the 

 Western End of Lake Ontario." For Part I., see this .lournal, Vol. 

 X., No. 3.) 



I. — INTRODUCTION. 



We have seen in Part I. of the " Geology of the Region about 

 the Western End of Lake Ontario" that a lars^e and varied 

 study may be made out of the exposures of the old rock-forma- 

 tions. In the present portion of the study, it will be found 

 that the Surface Geology is not only of local interest, for, from it 

 we are taught many things concerning the vexed subject of glacial 

 geology ; — about the origin of the Lower Great Lakes, the terraces 

 and the transportation power of pan or floe ice, besides the 

 physiography of the region before the advent of the Ice Age and 

 especially the causes which combined to form this very picturesque 

 region of Canada. 



In Part I, on the Palaeozoic Geology, a portion of the surface 

 features were described with reference to the exposures of Palae- 

 ozoic formations. The present descriptions of topography have 

 reference only to the Surface Geology. 



In order to more fully explain the causes which conspired to 

 bring about the present features, it is necessary to wander some- 

 what beyond the Region about the Western End of Lake Ontario. 

 The descriptions of the topography and a portion of the study of 

 the origin of the Lower Great Lakes have already been published ^ 



* " Discovery of the Preglacial Outlet of the Basin of Lake Erie into 

 that of Lake Ontario ; with Notes on the Origin of our Lower Great 

 Lakes." By J. W. Spencer, B.A.Sc, Ph.D., F.G.S., King's College, 

 Windsor, N. S. Ptead before the American Philosophical Society, 

 March 18, 1881, and published in the Proceedings of the Society. The 

 same paper was re-published in Report Q., of the Pennsylvania Geo- 

 logical Survey, with Notes by Prof. J. P. Lesley, the Director. A 

 portion of the paper on the Origin of the Lakes is copied from mj'^ 

 Paper on the subject, read before A.A.A.S., Cincinnati, Aug., 1881. 



