BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA 

 Vol. 1, pp. 311-334 April 9, 1890 



ON THE PLEISTOCENE FLORA OF CANADA. 



BY SIR WILLIAM DAWSON, P. R. S., AND PROFESSOR D. P. PENHALLOW, F. R.S. C. 

 (Read by abstract before the Society December 28, 1889.) 



CONTENTS. 



Page. 



I. Geology of the Deposits. By Sir William Dawson 311 



General Geology of the Pleistocene.,' 311 



Special Localities of Fossil Plants 316 



Geographical and Climatal Conditions , 318 



II. Notes on the Pleistocene Plants. By D. P. Penhallow 321 



Annotated List of Canadian Plants 321 



Description of New Species 327 



Kevision of previously recorded Pleistocene Plants 329 



Lignites 332 



Woods from Illinois :::;:: 



Synopsis 333 



I. GEOLOGY OF THE DEPOSITS. BY SIR WM. DAWSOX. 



General Geology of the Pleistocene. 



The Pleistocene deposits of Canada may be defined as consisting of three 

 principal members, which may be characterized as follows, in ascending 

 order : 



1. The Till, or lower bowlder clay, a tough or sometimes sandy clay, 

 containing local and traveled stones and bowlders, often glaciated. It 

 usually rests on glaciated surfaces, but is sometimes underlain by stratified 

 gravels or by old soil surfaces or peaty beds. These are, however, rare and 

 local.* In the more maritime regions — e. g., in the lower St. Lawrenc( — it 

 contains marine shells of arctic species. Farther inland — c. </., in western 

 Ontario and in the plains west of Red river — it is not known to hold marine 

 remains. 



2. Stratified clays and sandy clays. In the more maritime regions these 

 are the lower and upper Leda clays, holding many marine shells of boreal 

 rather than arctic types, especially in the upper part. They also contain 

 locally, drift plants, insects, and land or fresh-water shells, indicating the 



♦Acadian Geology, 1878, p. 03. 

 XLI— Bum.. Geol. Soc. Am., Vol. 1, 1889. ( 31 [ ) 



