162 NEW YORK STATE MUSEUM 



Washington county 

 Fort Ann 



In the report of the state museum for 1897, p. 529-32, a prelimi- 

 nary sketch of Fort Ann township is published together with a 

 partial map. The topography and the drainage are there briefly 

 described, and some notes on the petrography of the gneisses, 

 crystalline limestones and gabbros of the eastern part of the crys- 

 talline area are given. In August 1898 Mr Hill spent several 

 days in traversing the ridges in the central and western part of 

 the township and as the results of his observations, the map has 

 been extended as shown in the accompanying plate. The high 

 ridge of Putnam mountain and the ridge connecting Pilot Knob 

 with Sugar Loaf on the western limits of the town are all gneiss 

 and apparently of the same general character as that already 

 described from Pinnacle mountain. Basic hornblendic bands 

 have been noted in a few instances. Also, near Mt Hope, sheared 

 augite syenites of the " Whitehall type ", as described in our last 

 report, p. 507. Just west of Copeland pond gabbro has been dis- 

 covered in two places, viz, one on each of the highways. 



The boundaries of the gneisses as against the paleozoics have 

 not been sharply delimited in the southwestern part of the town- 

 ship, partly because of the abundant drift and partly from insuf- 

 ficent observations. There is one outlier of the Cambro-Silurian 

 strata that lies on the gneisses to the northwest of West Fort 

 Ann. It is shown on the map prepared by Charles D. Walcott to 

 accompany his paper on the " Taconic system of Emmons, etc." 

 (Amer. jour, of science. April 1888. pi. 3), and on the large, 

 geologic map of the state issued in 1894. While the crystallines 

 are drawn on the map where Mr Hill has observed them, the ob- 

 servations are not sufficiently detailed to revise the details of the 

 earlier map, and the latter is on a scale so much smaller that in- 

 corporation is unfeasible. 



One iron mine of considerable size was formerly operated near 

 Podunk pond. 



