THE MAXIMUM EXTENT OF PLEISTOCENE GLACIATION 353 



3. Wide areas of the High Arctic may have been covered by cold, thin, 

 stagnant ice, of which no trace remains today. 



From these three points it is apparent that much more systematic research 

 is needed. The following problems present themselves for urgent 

 consideration : 

 Outline of Problems for Future Investigation 



1. How does mountain-top detritus form? Detailed quantitative studies 

 of its structure and internal temperature conditions are required under 

 existing cHmatic conditions. Studies of the structure should establish whether 

 or not individual boulder fields pass downwards into bedrock and are 

 therefore the product of weathering in situ. Similarly, additional mineralogical 

 studies and intensive work on areal and vertical distribution in areas of 

 contrasting rock types are needed. 



2. Further investigations are needed to estabhsh the presence or absence of 

 glacial erratics on high coastal summits. Thus the Kaumajet Mountains, 

 southern Torngat, and Cape Dyer become critical areas. In the Cape Dyer 

 area it is beUeved that the outer coastal mountains, which rise to elevations 

 exceeding 1200 m, are composed of a Tertiary volcanic sequence. The 

 Tertiary outcrop is not more than ten miles wide and farther inland the 

 mountain country is composed of the regular Archaean gneisses. This should 

 provide an ideal situation for such a study. In any future attempt to estabhsh 

 the occurrence of erratics at high altitudes, Dahl's criteria should be used 

 (Dahl, 1961). 



3. Perhaps the most fruitful line of approach would be a more extensive 

 study of the history of glaciation in Labrador-Ungava and Baffin Island. In 

 this, particular attention should be paid to the problem of dating the lateral 

 and end moraine systems and to relating them to late and Post-glacial marine 

 phases. Especially important is the need to follow up the hypothesis that 

 Hudson Strait may have been largely ice-free during the Classical Wisconsin 

 maximum. 



All of these problems are being investigated as part of the northern research 

 programme of the Geographical Branch, Department of Mines and Technical 

 Surveys, Ottawa, Canada. 



Acknowledgments — The author expresses his indebtedness to numerous 

 colleagues who have either directly assisted in the field work or who have 

 discussed many aspects of the problems of interpretation of the field data. 

 Special thanks are due to Professor R. F. Fhnt, Dr. R. P. Goldthwait, Dr. E. 

 Dahl, Drs. Askell and Doris Love, Professors G. Hoppe and S. Rudberg, for 

 their many critical discussions and suggestions. In particular, the author was 

 fortunate to accompany Dr. Dahl on an excursion through parts of central 

 and western Norway in 1960 where the striking field evidence relating to the 



