2o8 The Ottawa Naturalist. [February 



to by Sir William Logan as existing in the Laurentian. On page 

 32 and 33 of the same volume, somewhat detailed descriptions 

 are given of conglomerates occurring in the Hastings Series then 

 classified as Laurentian. Vennor, in 1869,* gives a three-fold 

 classification of similar rocks occurring in the Hastings Series. 



In most if not all of these instances, there seems to have 

 been no well directed attempt to find the source of this coarse 

 fragmental material, or a basement from the disintegration of 

 which they might possibly have been derived. Of course at that 

 time such search was deemed unnecessary as the pre-existence 

 of the Laurentian was considered beyond question, and the 

 granitic aspect of most of the fragments seemed to point unmis- 

 takably to their derivation from similar material although their 

 exact source was not known. It will thus be evident that the precise 

 uature of these reported coarse fragmental rocks cannot be here 

 discussed as the descriptions at present available are necessarily 

 vague and unsatisfactory so that further examination will have to 

 be made at the several localities before a final decision can be 

 reached. 



In the region to the north of the occurrences mentioned in 

 thes2 old reports, several localities were however found where 

 pseudo-conglomerates are very typically developed. The most 

 noteworthy of these, showing very extended outcrops of these 

 rocks, are to be found in the northern part of the township of 

 Tudor between St. Ola Village and Gilmour Station on the 

 Central Ontario Railway. 



At this place also the true nature of these supposed con- 

 glomerates which it is the purpose of the present paper to 

 describe was first clearly understood. Other exposures identical 

 in origin were noticed on lot 18 con. Ill of Wollaston on the road 

 between Coe Hill and The Ridge P.O., on lot 10 con. XIV of 

 the same township a few miles east of Faraday P.O. ; also on 

 lot 26 Con. XIV of Carlow and on lot 2 con. XIX of Raglan. 

 These by no means exhaust the localities where similar rocks 



*See Rep. Geol. Surv. Can. 1866-69, p. 157. 



