SECOND REPORT OF THE DIRECTOR I905 



'5 



In the valleys of Seneca and Keuka lake there is a pronounced and 

 sometimes steep dip of the strata toward the lakes independent of the 

 general but irregular dip to the south. A similar condition exists 

 in the Genoa quadrangle where the dip is toward Cayuga lake. 

 This important determination indicates that these lake valleys are 

 not valleys of erosion alone but were originally the structural troughs 

 or synclines produced in the folding of the region and are hence of very 

 ancient date. 



The work on these quadrangles has been in charge of D. D. Luther. 



Morrisville quadrangle. This quadrangle embraces an inter- 

 esting area inasmuch as it covers the original and typical outcrops 

 of the Hamilton formation, a name which has entered into the no- 

 menclature of the New York rocks in the broad meaning of a group 

 term and whose original significance has been lost sight of. The 

 work here has been in charge of Mr H. O. Whitnall of Colgate Uni- 

 versity and has developed an admirable section extending from the 

 lower beds (Vernon shale) of the Salina, upward into the Ithaca 

 flags of the Neodevonic. The original Hamilton shale of Hamilton 

 is shown to be the uppermost member of the Hamilton stage and is 

 the undifferentiated equivalent of the Moscow, Tichenor, Canan- 

 daigua and Ludlowville units in the region farther west. Its uni- 

 form sedimentary facies and distribution of fossils does not permit 

 of subdivision. Of further interest is the entire absence of the Oris- 

 kany sandstone in this region though its presence both east and west 

 is well known. 



' Syracuse quadrangle. The northern part of this region has here- 

 tofore been somewhat avoided by the student of rock geology for it 

 is heavily mantled with drift and lacustrine deposits. There seem, 

 however, to be sufficient natural and artificial sections through the 

 overlying mass to make the elucidation of the rock succession clear 

 and final. The southern portion of the quadrangle includes the edge 

 of the plateau region and outcrops are frequent so that mapping has 

 proceeded with accuracy of detail. The work here has been in 

 charge of Prof. T. C. Hopkins. 



Valcour island. Valcour island lies in Lake Champlain about 5 

 miles south of Plattsburg. It has a length of about 2 miles, a 

 width of a mile and a half with an irregular coast line. It is a small 

 area but of special geologic interest both for the formations rep- 

 resented and the fossils available. Prof. G. H. Hudson has 

 undertaken to map the area on a larger scale than is afforded by the 

 topographic maps and to plot the geologic structure with corres- 

 ponding exactitude. The island presents a practically complete 



