32 Staten Island Association of Arts and Sciences 



and minerals recently collected, and to discuss their characters 

 and the conditions under which they were found. I am indebted 

 to Dr. Charles P. Berkey, of Columbia University, for the prepa- 

 ration of their sections for microscopic examination, and to Dr. 

 Alexis A. Julien, of the same institution, for their critical exami- 

 nation and the determination of their specific characters. 



The rock is traversed by a system of jointing which simulates 

 more or less closely the features of dip and strike in sedimentary 

 rocks. In fact deductions based upon these features alone would 

 justify the opinion expressed by earlier investigators that the 

 rock might represent a metamorphosed series of sediments. This 

 jointing is best seen in the vicinity of Richmond, near the Latou- 

 rette farm, and may be observed in- many of the bowlders scat- 

 tered over the morainal region to the south, some of which, when 

 broken and reduced to hand specimens, might well be mistaken for 

 shale or schist. 



Over the unglaciated area on Todt Hill and on the tops of the 

 hills at New Brighton and Tompkinsville, where glacial erosion 

 was limited, the rock is weathered into a soft, yellowish, fractured 

 condition, to which the name " soapstone " is generally applied. 

 In the vicinity of Richmond, where glaciation was more pro- 

 nounced, the upper, weathered zone was eroded and the rock 

 now exposed at the surface is hard and dense in texture and dark 

 green in color. 



One of the finest series of rock specimens and characteristic 

 minerals thus far obtained from the Staten Island serpentine area 

 was recently collected during the progress of excavating the 

 trench for the retaining wall along the east side of Jay Street at 

 St. George. A projecting spur of the serpentine escarpment was 

 cut away for a distance of some seventy-five feet, almost down 

 to tide level, exposing a vertical face twenty feet in height and 

 affording a view of the rock at a lower level than had been pre- 

 viously visible anywhere on the island. The serpentine rock was 

 very dark green in color, hard, and much seamed and fractured, 

 the fractures often filled with talc, marmolite, magnesite, calcite, 



