382 j^. A. Dalu— Post-Glacial Warping of 



case of the post-Glacial warping here considered. The 

 writer spent the season of 1920 in the effort to add to the 

 field data necessary for profitable attack on the difficult 

 problem. Among the regions where special investigation 

 has long been needed is Xewfoundland. The observa- 

 tions there made have been quite insufficient for the 

 mapping of the isobases or lines of equal uplift in post- 

 Glacial time. Accordingly, strategic points along the 

 Newfoundland coast were selected for study, in the hope 

 that the essential data for this area could be secured and 

 compared with the measurements already in hand for 

 northeastern Labrador and for the Nova Scotia-New 

 England coast. ^ Some time was also given to shore 

 studies in Nova Scotia, where the zero isobase has yet 

 to be definitely located and where the phenomena outside 

 the upwarped area are particularly of importance for the 

 geophysical interpretation of the post-Glacial deforma- 

 tion. 



In 1900 the writer found what appeared to be good 

 proof of post-Glacial uplift at St. John's, Newfoundland.- 

 The amount of elevation then measured — more than 

 500 feet — was too large to be readily understood if the 

 upwarping were either isostatic or purely elastic, but the 

 record seemed advisable. For twenty years the writer 

 has been suspicious of this result and a principal object 

 of the 1920 field-work was to become better acquainted 

 with the local facts at St. John's. The doubt was well 

 justified, the post-Glacial uplift at that point now proving, 

 practically beyond question, to be zero. One purpose of 

 the present note is to advertise the mistake. 



It is a pleasure to record the courtesy of the New- 

 foundland Department of Mines and Agriculture, who 

 supplied maps and reports used during the investigation. 



Methods of Determining Amount of Emergence. — As 

 a rule the same method was employed as that which in 

 1900 proved successful along 600 miles of the Labrador 

 coast. At each locality appropriate headlands were 

 examined for evidences of wave-washing. On the well- 

 exposed shores of both Labrador and Newfoundland, the 

 lower limit of unwashed glacial drift could usually be 

 located with considerable accuracy. Allowing for surf- 



^ For a bibliography of the subject, see H. L. Fairchild, Bull. Geol. Soc. 

 America, vol. 29, p. 229, 1918. 



2 E. A. Daly, Bull. Museum Comp. Zool., vol. 38, p. 257, 1902, 



