No. 2.] SPENCER — PREGLACIAL OUTLET OP L. ERIE. 71 



the surface of the country is more generally covered with Coruife- 

 rous limestone. 



Country between the Grand River and Dundas Valleys. The 

 watershed between these two present drainage systems is at only 

 a short distance southwest of Copetown, and the distance in a 

 direction from the Fairchild's to the Dundas side of this divide 

 is less than seven miles, with an average altitude of less than 480 

 feet (the same as that of the Fairchild's Creek, as it crosses 

 the Great Western Railway). The highest point that I have 

 levelled is 492 feet above Lake Ontario. On receding westward 

 from the divide, the country gradually descends to the Fairchild's 

 Creek, which as it crosses the Brantford and Harrisburg Railway 

 is 407 above the Lake. It is considerably lower where it enters 

 the Grand River. The region between the divide and the Grand 

 River is traversed from north-west to south-east by a considerable 

 number of streams, all with relatively large valleys, cut in the 

 drift, since the present system of drainage was inaugurated in 

 Post Glacial times. 



The country from Jerseyville (about 465 feet above lake) slopes 

 gradually to the Grand River, from six to eight miles distant to 

 the southward. 



On examination, it may be seen that the country is too high 

 to permit the Fairchild's Creek or Grand River, as they are at 

 present situated, to flow over the height of land into the upper 

 portion of the Dundas valley. As referred to before, the Niagara 

 limestone forming the summit of the escarpment at Ancaster 

 and eastward has a height of about 500 feet. These beds dip at 

 only about 25 feet in a mile (to about 20 degrees west of south) 

 and are not generally covered by a great thickness of drift, but 

 in many places are exposed on or near the surface. Westwa.rd 

 of Ancaster these limestones are nowhere to be found, but the 

 country is covered only with drift. At a short distance west of this 

 village, we find streams flowing north-easterly and easterly with 

 very deep valleys in the drift, indicating the absence of the floor 

 of limestone to a depth of over 250 feet below the surface of the 

 escarpment. But on going westward we find that the streams 

 have not cut to an equal depth, but are still running deeply 

 through drift. Eventually we reach the divide, after which we 

 find that other systems of streams also cut deeply in the drift 

 running in a south-easterly direction to join the Grand River ; but 

 the Niagara limestone is absent from a considerable extent of 

 country. 



