i\ 



68 NEW YORK STATE MUSEUM 



wide that an oceanic current could enter the epicontinental sea from 

 the northwest, bringing with it new faunal elements, and spreading 

 mud shales over a large area of eastern North America. 



The evidence of a deeper sea in the Levis channel, furnished by 

 the series of Lower Siluric graptolite shales, was also presented, 

 and the relations of the graptolite shales to the mobile parts of the 

 earth crust, the geosynclines, briefly mentioned. 



Friday evening the party went to Cliff Haven, 3 miles south of 

 Plattsburg, where the authorities of the Champlain Assembly had 

 placed at the disposal of Section E the New York cottage, in 

 which the party were delightfully housed for five days. Excursions 

 were made each day to various points, and in the evening all re- 

 turned to the broad piazzas of the cottage, where they sat and dis- 

 cussed the various trips, within a few feet of one of the striking 

 fault-line scarps of the region, looking out over the waters of Lake 

 Champlam. 



On Saturday morning, July 6, the party gathered on the steam 

 launch kindly furnished by the State of New York, and under the 

 guidance of Professor Gushing, Dr Ruedemann and Professor Hud- 

 son, took a charming sail on Lake Champlain. The party visited 

 Crab and Valcour islands and studied the Palezoic sediments 

 which are there so beautifully exposed with their many interesting 

 structural features. 



At noon the party enjoyed the delightful hospitality of Prof, and 

 Mrs George H. Hudson of Plattsburg at their charming camp on 

 Valcour island. After lunch a talk was given by John M. Clarke 

 on 



Lake Champlain 



Dr Clarke spoke of the origin of the Lake Champlain valley as 

 the result of a series of downthrown fault blocks having the evident 

 aspect of a grabcn. He referred to the later evidence as confirm- 

 atory of Logan's conception of the Lake Champlain fault and indi- 

 cated that this origin was borne out by the present attitude of the 

 downthrown Paleozoics- against the abrupt eastern scarps of the 

 Adirondack crystalline shield. 



Reference was also made by the speaker to the possibility that 

 the geographical name Trembleau, which designates the prominent 

 headland and mountain ridge just south of Port Kent, embodies 

 the recoid of an ancient seismic disturbance, and with this as a text 

 fuller reference was made to the Canadian earthquake of 1663 



