[parks] presidential ADDRESS 27 



FOERSTE's classification of the ORDOVICIAN— ConC</ 



Lorraine 



Maysville 



Eden 



Horizon undefined 

 Utica 



Collingwood 

 Trenton 



Older Ontario 



The chief contribution to the stratigraphie geology of lower 

 Ontario in the early part of our period was the "Hamilton Group of 

 Thedford, Ontario," published in the Bulletins of the Geological 

 Society of America by Shimer and Grabau in 1902. The authors 

 divide the formation into five faunal zones, give complete lists of 

 fossils, some new, also interesting discussions of the phylogeny of 

 type forms and correlation with American deposits. 



Grabau and Scherzer in a study of the Monroe formation, pub- 

 lished by the Michigan survey in 1909, did much to clear up the 

 complicated problem of the Silurian-Devonian contact in Essex 

 county. Their conclusions, which have not gone unchallenged, were 

 as follows: — ■ 



GRABAU AND SCHERZER's DIVISIONS OF THE MONROE FORMATION 



Dundee (Onondaga) 



Monroe formation 

 Monroean 



Upper Monroe Lucas dolomite 



or Amherstberg dolomite 



Detroit River Anderdon limestone 



series Flat Rock dolomite 



Sylvania sandstone and dolomite 



Lower Monroe Raisin River dolomite 



or Put-in-Bay dolomite 



Bass Island Tymochtee shales 



series Greenfield dolomite 



Salina formation 



Important contributions to this question were also made by 

 Rev. Thomas Nattress in 1910 and 1911. 



The first sign of revival on the part of the Canadian authorities 

 was the appointment of Dr. C. R. Stauffer, then Professor of Palae- 



