BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA 

 Vol 34, pp. 609-648. PLS. 5-12 SEPTEMBER 30. 1923 



EANGE ANB DISTRIBUTION OF CERTAI^^ TYPES OF 

 CANADIAN PLEISTOCENE CONCRETIONS ^ 



BY E. M. KINDLE 



{Presented hefore the Society December 20, 1922) 



CONTENTS 



Page 



Introduction 600 



Nomenclature of concretions 611 



Labrador concretions 614 



Slave River concretions 617 



British Columbia concretions 617 



Ottawa Vallej' concretions 620 



General statement 620 



Rideau River and Greens Creek section.. 621 



Concretions of the lower clays 621 



Concretions of the upper clays 626 



Pleistocene sand and shell concretions 627 



Summary 683 



Discussion 6^M 



Bibliography 63r» 



Explanation of plates 647 



IJsTTRODUCTION 



Concretions do not lend themselves to the exact methods of descrip- 

 tion used by the mineralogist. Paleontologists are likely to mention 

 them only casually in connection with the fossils which they often inclose. 

 Other geologists are apt to let them severely alone save for the briefest 

 possible mention. Concretions may therefore be said to belong to a sort 

 of "no-man's-land" in geology. Notwithstanding excellent descriptions 

 of particular kinds of concretions which have appeared^ we are still with- 

 out criteria which will enable geologists to agree as to whether certain 

 forms are of organic or inorganic origin. Cases have been recorded 



^ Manuscript received by the Secretary of the Society February 20, 1923. 

 Published with the permission of 'the Director, Geological Survey of Canada. 



XL — Bull. Geol. Soc. Am., Vol. 34, 1922 (609) 



