New York State Museum 



GEOLOGY 



Owing to the liberal aid received from the legislature of 1899 

 and 1900, the director and state geologist is enabled to report 

 a very satisfactory degree of progress in the work under his 

 supervision. 



In the field of geology the following is a synopsis of the results 

 accomplished. 



PRE-CAMBRIAN AND CRYSTALLINE ROOKS 



The resurvey of Westchester county, begun some years ago by 

 the present state geologist and since continued under his direc- 

 tion, has been carried nearly to completion by Edwin C. Eckel, 

 assistant in geology, and Harry C. Magnus, volunteer assistant. 



During the month of October Mr Eckel was engaged in areal 

 work in Westchester county, covering the region near the Croton 

 river. Kecords of borings for dam sites along the Croton river 

 were obtained from Alphonse Fteley, chief engineer of the Croton 

 aqueduct, and the materials shown by these borings were re- 

 ferred, so far as possible, to their respective geologic formations. 



From Nov. 1 to Jan. 15 he was employed on field and office 

 work in the final revision of the geology of the Harlem quad- 

 rangle for the New York folio. In order to use all new informa- 

 tion rendered available by recent excavations, a number of bound- 

 aries were retraced, and careful search was made for records of 

 borings on and near New York island. As several Jersey City 

 records mentioned the occurrence of " gneiss," several days were 

 spent searching for outcrops in Jersey City and in mapping the 

 serpentine area at Hoboken. 



His time from March 8 to April 8 was occupied with the final 

 drafting of the geology of the Harlem quadrangle. During the 

 remainder of April and all of May he was engaged in detailed 

 work on the Carmel quadrangle and in reconnaissance work in 

 Fairfield county, Ct. This work proved that the two bands of 

 Harrison diorite shown in Westchester county on the map of 

 1895 unite in Connecticut and cover a large area. 



