of the Paleozoic Outlier of Lake Timiskaming. 307 



feet thick, and from calculations made on the average 

 thickness of the bands, this represents at least 2000 years 

 for deposition. In a well drilling at Uno Park 216 feet 

 of clay were passed through, and at the town of New Lis- 

 keard near Wabi creek there was 100 feet. It is possible 

 that this may not all be stratified clay, but as the New Lis- 

 keard well does not represent the maximum depth nearer 

 the fault-line to the west, it is thought that 250 feet for a 

 total thickness of the clays would be a very conservative 

 estimate. This would mean at least 3600 years for the 

 duration of Lake Barlow. It therefore appears certain 

 that this lake lasted at least 2000 years, but the probability 

 is that the larger figure of 3600 is more nearly correct. 



Economic Geology. 



Water supply. — The fault which has formed the 

 straight western shore of Lake Timiskaming and its con- 

 tinuance seen in the fault-line scarp northwest of it, has 

 brought about a tilting of the Paleozoic strata to the west 

 in all of the area on the east side of the fault-line. Except 

 for a ridge of rock extending northwest from Wabi penin- 

 sula, the whole surface is now covered by the clay deposits 

 of Lake Barlow. These clays are relatively impervious 

 to water, and the settlers have found that surface wells 

 are for the most part unsuitable for human use. The 

 problem of water supply is therefore very important to 

 the agricultural development of this district, and in many 

 places deep well boring has been done. In the final report 

 a list of such well records will be published and a detailed 

 account given. 



In the low plain which includes the valley of Wabi 

 creek and a strip of country to the west of Earlton and 

 Thornloe and east of the Paleozoic boundary on the west, 

 a great many wells have been obtained and artesian wells 

 are not uncommon. The rocks under this plain dip west, 

 but on the east they outcrop as a ridge stretching north- 

 west from Wabi peninsula. It has been found that be- 

 tween the clay and the underlying westward dipping lime- 

 stone there is a layer of bowlders which are the glacial 

 materials left on the retreat of the continental ice sheets. 

 This layer of bowlders is very favorable for the permea- 

 tion of water along the upper surface of the limestone, and 

 it has been found that good wells frequently develop as 

 soon as the layer of bowlders is tapped. 



Am. Jour. Sci— Fourth Series, Vol. L, No. 298.— October, 1920. 

 22 



