4 



NEW YORK STATE MUSEUM 



INTRODUCTION 



The Mooers quadrangle includes an area of about 225 square 

 miles c overing a part of the northeasternmost spur of the Adiron- 

 dack^ and the gravelly and sandy lowlands west of Lake Cham- 

 plain. The international boundary line between New York and 

 the Dominion of Canada forms the northern limit of the map 

 [pi. 1]- 



The geologic description of the hard rocks of this area has 

 already been given in a bulletin of the Museum by Professor Cush- 

 ing. In this and earlier reports published under the auspices of 

 the Natural History Survey of the State, brief references are made 

 to the glacial and postglacial deposits which in this district oc- 

 cur along the margins of Lake Champlain. In the appendix to 

 this paper will be found a list of the principal references, a num- 

 ber of which are quoted in the text. 



The Pleistocene geology of this area is of peculiar interest be- 

 cause of the submergence of the Lake Champlain district beneath 

 the sea in the closing stage of the Pleistocene period. The detailed 

 study of the area was undertaken for the purpose of obtaining a 

 more complete and accurate knowledge of the shore lines of this 

 epoch of marine submergence than could be gained by the rapid 

 reconnaissance conducted by the writer in reference to the same 

 problem in the major portion of the valleys of the Hudson and 

 Lake Champlain. 



It is necessary to state here that the author found, on selecting 

 this area for examination, that he had been preceded in the same 

 quest by Dr G. K. Gilbert, of the United States Geological Sur- 

 vey. Through Dr Merrill, state geologist, Dr Gilbert very gener- 

 ously offered his field notes for such use as could be made of them, 

 not only for the Mooers district but also for the northern flank 

 of the Adirondacks as far Avest as Lake Ontario. These notes have 

 been used first as guides for localities to be visited and secondly 

 as important checks on the observations and conclusions of the 

 writer, who wishes here to express his great indebtedness to 

 Dr Gilbert. 



SURFACE DEPOSITS OF THE AREA 



The surficial or loose deposits of the Mooers quadrangle so far 

 as known, pertain altogether to the Pleistocene period or to more 

 recent accumulations which are still in progress. For the most 



