1^70 Canadian Record of Science. 



3. The Saguenay anorthosite area. 



4. Various other anorthosite areas. 



(a) In Labrador. 



{/>) In Newfoundland. 



(c) On the north shore of the Gulf of St. Lawrence. 



(d) On the north shore of the River St. Lawrence. 



(e) In the State of New York, U. S. A. 

 (0 On the east coast of Lake Huron. 

 ((f) Elsewhere in Canada. 



5. Age of the anorthosite intrusions and their relation to the margin 



of the archaean protaxis. 



6. Occurrence of similar anorthosites in other countries. 



7. General summary of the results. 



8. Tables of analyses. 



9. Literature relating to the anorthosites of Canada. 



The present paper is based upon a study of the Canadian 

 anorthosites in the field, a work which was carried out for 

 the Geological Survey of Canada and occupied five sum- 

 mers, as well as upon the examination of a large number of 

 thin sections of these rocks and a careful study of all the 

 literature relating to them. 



The petrographical part of the work was done for the 

 most part in the Mineralogical Institute of the University 

 of Heidelberg, and I take the liberty of expressing my 

 hearty thanks to my teacher, Professor Eosenbusch, for his 

 assistance and advice during the progress of the work. 



I am furthermore under special obligations to Dr. A. E. C. 

 Selwyn, Director of the Geological Surve} 7 of Canada, for 

 permission to make use of material hitherto unpublished 

 and which is the property of the Geological Survey Depart- 

 ment. 



I.-GENEEAL STATEMENT CONCEENWG THE 

 GEOLOGY OF THE LAUEENTIAN. 



The nucleus of the North American continent consists, as 

 is well known, of a large area of Archaean rocks which lie, 

 for the most part, in the Dominion of Canada, and occupy 

 an area of not less than 2,031,000 square miles. They form 

 what Suess l calls " the Canadian shield " as well as the 

 more mountainous district along the coast of Labrador. 



1 Suess, Das Antlitz der Erde, Bd. II., p. 42. 



