Dec, 1912.] Ordovician Section, Lake Huron Area. 37 



THE ORDOVICIAN SECTION IN THE MANITOULIN AREA 



OF LAKE HURON. 



Aug. F. Foerste. 



1 . Introduction 37 



2. Basal beds; red clay shales; Lowville 38 



3. Swift Current beds; chiefly whitish limestones; Leray 38 



4. Cloche Island beds; "Black River" limestones 39 



5. Curdsville and other Trenton exposures on Goat Island 41 



6. Trenton exposures at Little Current, including Collingwood 



formation 42 



7. Cincinnatian beds on Manitoulin Island 43 



A. Sheguindah beds; Eden 43 



B. Wekwemikongsing beds; Lorraine 44 



8. Richmond strata on Manitoulin Island 45 



C. Waynesville beds, or Lower Richmond 45 



D. Kagawong beds, or Upper Richmond 46 



Columnaria reef 46 



Stromatocerium reef 47 



Rhy timya and ostracod horizons 47 



E. Queenstown shales 47 



1. Introduction. 



During the summer of 1911 and 1912, the writer was given the 

 opportunity, b}^ Dr. R. W. Brock, of visiting the Ordovician sec- 

 tions in the Lake Huron area under the auspices of the Canadian 

 Geological Survey. During the first summer he was accompanied 

 by Prof. Arthur M. Miller, who made a special study of the 

 Mohawkian strata on Cloche and Goat islands, and in the vicinity 

 of Little Current, and Avho gave him the benefit of his extended 

 acquaintance with Mohawkian strata, especiaUy in relation to the 

 correlation of these strata as exposed in the Lake Huron area with 

 those of Kentucky. During the summer of 1911, and during a 

 part of 1912, he had also the assistance of Mr. E. J. Whittaker, of 

 the Canadian Geological Survey, especially in his investigations of 

 the Cincinnatian strata. Mr. Whittaker has since given special 

 attention to the Cincinnatian strata in the vicinity of Meaford, 

 and some of his observations are here incorporated. The notes 

 here presented are merely preliminary to a more extended study 

 of the field. 



As will be noted on the following pages, the writer has had the 

 frequent assistance of Dr. E. O. Ulrich, Mr. R. S. Bassler, Prof. 

 Percy E.. Raymond, Dr. Rucdemann, and others, in the interpre- 

 tation of the fossil faunas. It will be readily recognized, however, 

 that these investigators were at a disadvantage in not being able 

 to examine the faunas themselves in the field, since the writer may 

 have failed to collect some of the most valuable diagnostic fossils. 



