722 ABSTRACTS OF PAPERS 



Discussion 



Prof. J. B. WooDwoRTH stated in brief tliat the pool and accumulation of 

 blocks in "the Gulf" at Covey had been interpreted by Gilbert, himself, and 

 others as evidence of a torrential flow of waters out of all proportion to the 

 existing stream. As for the altitude of the upper marine limit on the north 

 side of Covey Hill, he had revisited the field since the paper, "On the ancient 

 water-levels of the Hudson-Champlain Valleys," was published, in company 

 with Professor FairchlV and accepted the latter 's determination of the upi)er 

 marine limit. The eievations given in that report were based on an old and 

 inaccurate altitude of Covey Hill, and can not be relied upon. 



Prof. H. L. Fairchild: Dr. Spencer's present views are a great change 

 from those of the last twenty years, during which he has advocated the ma- 

 rine origin of all the glacial lake beaches, including the Iroquois. Now he 

 doubts the marine origin of the lowest series of close-set bars in the Cham- 

 plain- Saint Lawrence depression, and which clearly correlate with deposits 

 containing marine fossils, and which have for nearly a century been recog- 

 nized by all workers as oceanic. There can be no doubt of the marine origin 

 of the Covey Hill beaches. The deformation of the Iroquois plane clearly 

 proves that the Covey Hill bars were below sealevel at the close of the 

 Iroquois time. The absence of a great cataract cliff at the Covey Gulf is 

 due to the fact that the ice-sheet lay close against the west slope of the 

 Champlain Valley or the east slope of the Covey Hill promontory, and the 

 outflow of Iroquois waters at the gulf was held up at high level and produced 

 the extensive areas of bare rocks on the Mooers quadrangle, formerly de- 

 scribed by Professor Woodworth. The history of this locality will be given 

 and the features described in my paper, "Closing phase of glaciation in New 

 York," to be delivered later in this meeting. 



Dr. Spencer replied : Points emphasized in my paper are : That Covey Hill 

 Gulf is due to postglacial local erosion and not to drainage of a glacial lake ; 

 that the spillway over the hill was from a glacial lake other than the Iro- 

 quois, probably an older one ; that I saw no evidence then of any of the 

 beaches being marine. In making the original surveys of lakes Warren, 

 Algonquin, and Iroquois, I had adopted the hypothesis that they were not of 

 glacial origin. At that time the phenomena of the spillways had not been 

 well investigated. Since my return to these researches I have accepted gla- 

 cial dams on fuller evidence. For this change of hypothesis, or progress, my 

 friend, Professor Fairchild, would impale me. But my former argument in 

 favor of the marine origin of Lake Iroquois he has adopted in support of 

 Gilbert Gulf, of whose existence I have failed to find evidence. 



GEOLOGY OF STEEP ROCK LAKE 

 BY ANDREW C. LAW SON 



(Abstract) 



The paper gave a brief historical summary of the geology of Steep Rock 

 Lake and an account of a visit to the lake during the summer of 1911. The 

 observations that were made confirm the conclusion of Smyth as to the exist- 

 ence of the Steep Rock series as a distinct member of the Archean and its 



