1881.] Oi^i [Spencer. 



on the topography, this broad valley continues to Cayuga within a few 

 miles of the lake, whence its former probable course was by a nearly 

 direct line to Lake Erie, now filled with drift, near the present bend in 

 the river towards the eastward. At Cayuga, the rock beneath the drift-bed 

 of the river is below the lake level, on the margin of its ancient valley. 

 (See note, Section II.) * 



Having observed the connection between the Dundas valley, Grand 

 river and Lake Erie, it dawned on me that I had established the knowledge 

 of a channel having a very important bearing on the surface geology of 

 the lake region. It now became apparent that Lake Erie had flowed by 

 the Grand river reversed to a point west or north-west of Seneca, and 

 thence by the Dundas valley into Lake Ontario ; also that the upper 

 waters of the Grand river, previously discovered as passing down the 

 Dundas valley, were really tributary to the outlet of Lake Erie, and joined 

 it somewhere south of Harrisburg ; and that the basin between the Brantford 

 (and the Grand river of to-day) and the Great Western Railway, at Cope- 

 town, formed an expanded lakelet along the course of the ancient outlet of 

 Lake Erie, scooped out of the softer rocks of the Onondaga Formation be- 

 fore noticed. As the waters excavated a bed in a deeper channel, of course 

 this lakelet would become an expanded and depressed valley, such as we 

 often see amongst the hills of drift, at a short distance westward of Dun- 

 das. Possibly the Grand river divided and flowed around an island, the 

 western side of which is occupied now by the town of Paris. At any rate, 

 Neith's «;reek, at that town formed a large tributary to the river then 

 flowing down to Lake Ontario. 



Along the course from Cayuga to Lake Ontario all obstacles to the outlet 

 of Lake Erie appear to be removed. But along the present course of the 

 Grand river, eastward of Cayuga, the waters flow over Coniferous lime- 

 stone. But this difficulty is removed on observing that the river, filled 

 with drift, approaches Lake Erie to within a direct distance of about six 

 miles, but that at this place it leaves its southward course and also its C(m- 

 spicuous valley and flows eastward, in the same manner as the Niagara 

 river, above the Whirlpool, left its old choked-up outlet by the valley of 

 St. David, and cleaned out a new channel for itself through several miles, 

 in hard rock, from Queenston southward. 



We have recently seen by a note in the second section of this paper, that 

 the Grand River bed is near the eastern margin of its ancient valley at 

 Cayuga. From northward of this town, at about half a mile to the west- 

 ward of the river, a deep depression in the drift indicates the deeper por- 

 tion of the ancient river as it left the modern channel direct for the Lake 

 Erie basin. Also along this route the hard rock is known to be absent to 

 a depth below the surface of Lake Erie. 



In Ohio, the Geological Survey considers that Maumee river emptied into 

 the Wabash. If the waters of Lake Erie ever passed by this route into the 

 Mississippi river when they were at no higher level than at present, then 

 there must be a channel buried to a depth reaching at least 170 feet above 



