S6 



\re find they are connected by a similar ridj^e, 1 lit the rocks of which are here- 

 only exposed at ihe surface over a limited extent in the rerr of the Indian- 

 Reserve at Oka, while the rest of this old ridge is concealed liy a covering of fiat 

 lying strata of sandstone. Within these limits 125 miles long and about 50 mile* 

 wide lies what may be geologically described as the Ottawa Valley Pala?ozoic 

 Basin. 



This basin must, for immense periods of time have been occupied by the 

 water of the ancient lower Pahiiozoic sea; whether continuou.sly or with inter- 

 vening periods of dry land is uncertain. Portions of it, however, were certainly, 

 in its earlier stages, either shore lines or shallow tidal flats dry at low water, as 

 evidenced by the tracks of animals and wind ripple marks, all of which you can 

 see fine examples of in the Geological Museum. Slowly and gradually, however, 

 the basin became filled by successive layers of sedimentary matter, pebbles, sand, 

 mud, lime, forming the sandstone, shales and limestones which make up the so 

 called Cambrian or Carabro-Silurian systems and formations. 



Almost every layer of these ancient rocks is to the industrious geologist, 

 aided by pick and hammer, as it were the pages of a voluminous work in which 

 he can study and decipher the history, life habits, and surroundings of successive 

 generations of animals and plants, similar though in no case identical with those 

 which now inhalat our seas and continents. 



The portions of this voluminous old manuscript which arefnsented for our 

 perusal and t-tudy in the Ottawa Valley may be designated : 

 Vol. C. — Chapter 1 and 2. 

 Vol. 1).— Chapter 1, 2, and 3, 

 otherwise known as : 



0. — Cambrian System — Potsdam and Calciferous Formations. 

 D. — Cambro-Silurian System — Chazy: Black River; '1 ronton: Utica and Hudson 



River Formations. 

 The seven volumes from E to L inclusive, in which are written the records of 

 millions of centuries, and of manx- generations ot animals and plants, appear never 

 to have been placed in the Ottawa Valley library, or else they have since been 

 lost, stolen, or destroyed. Vol. M, the last ot the series, is, however, to be found 

 there in excellent preservation and offers many interesting and instructive pages, 

 though its widespread occupation of the shelves often proves a serious hindrance 

 to the study of the earlier volumes, and makes one wish it had shared the fate of 

 the seven missing volumes referred to. 



The names given to the formation are all taken from the localities in the 

 State of New York where they were first studied by American geologists, and 

 the names have been adopted by Sir W. Logan for Canada, with the addition, how- 

 ever, of three new and purely Canadian names, Levis, Lauzon, and Sillery, making 

 what he has called the Quebec (iroup, at the same time stating that ii repre- 

 sented the Calciferous and Chazy formations. Each of the formations I have 

 named and which have together filled in the Ottawa basin to a depth in some 

 parts (<f perhaps 1,500 or 2,000 feet, is supposed to be characterised by a peculiar 

 and distinctive assemblage of life form, and the discovery of any of the indi- 

 vidual species of these groups in <an outcrop is sometim- s held to be sufficient 

 evidence for determining the formation to which the outcrop belongs. Such 

 evidence is doubtIe^s an invaluable aid to stratigraphy, but we must bear in 

 mind that it is at best negative evidence, and it may be that some fossil which 

 we have for a long time considered to be characterist'c of a peculiar formation 

 may suddenly be discovered in the strata either much higher or much lower in 

 the series, and more especially is this likely to occur in new and only imperfectly 

 examined regions. Too much reliance on imperfect pala^ ntologic al evidence has, 1 

 think, led to many grave errors and complications in Canadian stiatigraphy, and 

 to needltss multiplication of formations and group"^. the introduction of which 

 tends to complica'e stratig-aphical work. Often such formations represent only 



