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NEW YORK STATE MUSEUM 



elusions representing those parts last torn away from the cover 

 formerly overlying the granite which was then in such viscous con- 

 dition that the inclusions have moved but little from their point of 

 detachment. Unlike the granite gneiss, this Picton granite was 

 well supplied with mineralizing agents and has produced consider- 

 able contact effect on the adjacent rocks, notably a striking develop- 

 ment of tourmalin. 



There is also a considerable development of wide trap dikes on 

 Grindstone and Wellesley islands from which an abundant and 

 cheap supply of the very best road rock can be readily obtained. 



Eastern Adirondacks. The mapping of the Elizabethtown- 

 Port Henry quadrangles is reported by Professor Kemp as prac- 

 tically complete and the manuscript of the bulletin prepared. This 

 is a complicated region including the extensive iron bodies of Mine- 

 ville and vicinity and has required repeated review. An exposition 

 of the Mineville mines and ores prepared by Professor Kemp has 

 been published during the year as a special part of Bulletin 119, 

 Geology of the Adirondack Magnetic Iron Ores. The regions 

 referred to carry, along the shore of Lake Champlain, an in- 

 teresting display of the Paleozoic formations which have been 

 specially reviewed by Dr Ruedemann who has found that the 

 Paleozoic areas which are of semioval or semielliptic shape, open- 

 ing toward the lake and suggesting embay ments, consist of groups 

 of small fault blocks bounded on the west by northeasterly master 

 faults and broken up again by transverse faults at various angles 

 to the former. The small blocks may dip in various directions but 

 hold a prevailing dip away from the mountains or toward the east. 

 The work on the Ausable and Westport quadrangles has progressed. 

 The geology involved herein is similar to that on the Elizabethtown 

 and Port Henry sheets and with the adjustment of the latter, the 

 other work will lend itself to readier solution. 



Southeastern New York. Geology of the Hudson Highlands 

 and cooperation with the New York City Board of Water Supply. 

 An agreement entered into in the past year by the chief engineer 

 of the Board of Water Supply of New York City and the State 

 Geologist gives to the latter access to the highly important records 

 of dcej) seated geologic structure from the southern Catskills 

 southward to the mouth of the Hudson, acquired in the course of 

 the remarkable engineering undertaking with which that board 

 is concerned. By innumerable deep borings on both sides of the 

 Hudson river and through its bed. in a region where the geology 

 is highly complex, the operations of the board's engineers have 



