32 NEW YORK STATE MUSEUM 



tion of a small quantity of chrysotile or serpentine asbestos. The 

 latter occurs principally within a small but rather persistent zone of 

 the limestone that takes a northeasterly course parallel to the general 

 structural trend. Within this zone occur numerous veinlets that 

 carry a very light, silky asbestos of a maximum length of about an 

 inch, most of which is apparently of good quality. The veins are 

 not persistent, but thin quickly and merge into the massive serpentine 

 of the country rock. Outside the main zone, bunches of serpentine 

 are to be seen which are shot through with fiber, or show the presence 

 of whitish asbestiform material. The general average of the fiber 

 is probably not more than one-fourth of an inch. Samples were 

 shipped by the owner of the property to asbestos manufacturers 

 who reported favorably upon its quality. Although a part of the 

 rock, no doubt, is of workable grade, not a very large quantity of 

 that kind has as yet been exposed in the workings. 



A small prospect showing serpentine asbestos of fairly long fiber 

 was seen by the writer some years ago on the north side of Brant 

 lake, in the town of Horicon, Warren county. It is not known by 

 whom the property was explored, but apparently the results did 

 not warrant a continuance of the work. 



Serpentinous limestones are also found in the Highlands region 

 in Putnam and Orange counties; from the locality in Philipstown 

 east of Cold Spring many samples of chrysolite have been gathered 

 for museimis. Mather in the New York Geological Reports for 

 1839 mentions an occurrence at Cotton rock in the same town on 

 the bank of the Hudson, 35 miles below West Point. 



On Staten Island and near the Village of Rye, Westchester county, 

 are bosses of serpentine which ftimish the closest parallels to the 

 Canadian and Vermont occurrences. The Staten island boss has 

 a surface of about 1 5 square miles and constitutes the central elevated 

 part of the island. The rock is apparently an igneous derivative, 

 as unaltered remnants of olivine and pyroxene have been discovered 

 in it. Both amphibole and serpentine asbestos occur within the 

 area, the former variety being restricted to the border where the 

 serpentine is in contact with schistose rocks belonging to the 

 Manhattan formation. Examples of amphibole asbestos have been 

 collected from Pavilion hill near Tompkinsville and at Fort George; 

 one specimen found by the writer near the latter place possessed 

 fibers nearly a foot long. Chrysotile is less common, but a very 

 few years ago was still to be found on Pavilion hill. 



