THE PELHAM AND WILBKAHAM AREA. 55 



THK PELHAM SERPENTINE. 



About 325 feet west of the asbestos mine, on a small flat which inter- 

 rupts the western slope of the hill on the eastern side of which the mine is 

 situated, a great boss of serpentine rises thi-ough the till, and a little south of 

 it a second, of which it can only be said that they occur within the limits of 

 the Monson gneiss. The rock is a deep dull-green, opac^ue when wet, and 

 containing chromite in some abundance. Over a large portion of its sm-face 

 it is changed for some distance inward into a white talc, and as this change 

 follows the surface of the rock it is plainly a change of the serpentine into 

 talc since the erosion of the Glacial pei-iod. 



TH«: SHUTESBUUY SERPENTINE. 



A second locality identical with the "asbestos" mine in Pelham occurs 

 a mile south of the village of Shutesbury, in a pasture south of the house 

 of C. Leonard. Fragments, some of large size, lie over the surface in a 

 space a few yards square, turned up by plowing. One large mass of 

 rusty-brown, half-decomposed olivine rock, shot through by white authophyl- 

 lite fibers and full of chi-omite, is not to be distinguished from similar 

 masses at the Pelham locality. The fibrous asbestiform and woody varieties 

 of anthophyllite are repeated here also, and masses of a green chlontic 

 mineral occur. The deposit is surrounded on all sides by outcrops of the 

 Monson gneiss, but its exact relation and size can not be determined. 



THE NEW S.\I.EM SERPENTINE. 



This locality is situated uu the west slope of Rattlesnake Hill, aljout 

 300 yards northeast of A. A. Haskell's house. The country rock is a rather 

 coarse biotite-granitoid gneiss, striking north-south and dipping 1)0=. The 

 old digging is covered, and no contacts can be seen. The oU^^ne rock is 

 at most 50 feet wide and may be 150 feet long. The nearest outcrops of 

 the gneiss are wholly normal and do not betray the presence of the foreign 

 body. This is apparently a lenticular mass, its greatest diameter coinciding 

 with the strike. The greater portion of the rock taken out is deep dull- 

 l)lack ohvine, with small glistening scales of a micaceous mineral, appar- 

 ently clinochlore. The rock weathers to a pale isabella-yellow from the 

 removal of the black ore and the hydration of the olivine. Associated 

 with it in some quantity is a fine fibrous light-gray anthophyllite, largely 

 altered to an imperfect steatite. I was guided to the spot by an aged man 



