Glacial geology of Grand Manan Island, New Brunswick: Discussion

Abstract

Robert Legget's review of and contribution to knowledge of the glacial geology of Grand Manan Island bring forward a number of pieces of new information and present several other aspects that make his paper a most welcomed and interesting note. My main concern is that there are sections in the paper that leave me wanting further observations. Perhaps Mr. Legget could be encouraged to have a second look at some few localities and phenomena on future visits to the island. Aside from the steep rock faces ranging up to 120 high (p. 441, col. I), I am obliged to note that the author has referred to a large number of localities not shown on the only map. The author could have been influenced to use a more detailed map at larger scale so that all pertinent sites might be located more readily. Of less frivolous concern is the matter of the origin of the flocks of sheep (p. 446 et seq .). To this reader, the most significant fact presented in the description and in the illustrations of this phenomenon is that some of the larger boulders on the landward side of the flock are embedded in gravel and sand. The body of gravel and sand has a flat upper surface (e.g., Figs. 9b, 10) reminiscent of raised wave-washed surfaces on the New Brunswick mainland. The material appears to be very similar in nature to the material overlying till shown in Fig. 5, except perhaps for the maximum size of boulders. Because the flocks of sheep and the associated bouldery gravel and sand apparently lie not much more than 4 m above present sea level (my estimate from Fig. 9 a and b), and because marine fossils have been collected from a similar level (4 m above HWOST, p. 451, col. l ) , would it not be possible to suggest, as a working hypothesis, that the bouldery gravel of Figs. 5