370 



Scientific Geology. 



dip and direction of the strata conforming to those of the mica slate, 

 Its predominant colour is black : but it contains a mixture of indurat- 

 ed greenish talc, and an amphibolic mineral of a gray colour. (No. 

 893.) A considerable part of the rock, however, contains granular 

 carbonate of lime : or rather in some parts of the bed this mineral 

 predominates, and the serpentine is disseminated through it in small 

 pieces. (No. 899.) 



Nearly half a mile north of this spot, serpentine again appears on 

 the noth bank of Westfield river in Russell ; and I have strong reas- 

 ons for believing it to be a continuation of the bed in Westfield, just 

 described. The rock in Russell is a mixture of black serpentine with 

 green, the latter being sometimes very compact and traversed by 

 veins of indurated talc (?) or Deweylite. (?) (No. 885.) 



I can hardly doubt but many more beds of serpentine might easily 

 be discovered in the Hoosac mountain range, if ever it shall be an ob- 

 ject to make such discoveries. I make this inference from the fact 

 that I have found some of those above described, under circumstances 

 the most unfavourable. 



On the east side of Connecticut river but few beds of serpentine 

 have been found in Massachusetts. That marked in Pelham occurs 

 in the southwest part of the town, and exhibits itself over an area of 

 only a few square rods. One may doubt whether this rock should be 

 called serpentine, or steatite : for these two minerals enter into its 

 composition. In general, however, the latter, which is of a black 

 colour, predominates. It also contains a considerable quantity of as- 

 bestus. This bed lies in gneiss ; although the actual contact is hid- 

 den by the soil. But at a little distance on both sides this rock ap- 

 pears, and no other rock occurs in the vicinity. 



The steatite marked as occurring in Shutesbury appears to be pas- 

 sing in some parts into black serpentine ; as may be seen from the 

 specimen No. 805. At the steatite bed in New Salem this change is 

 still more decided, so that large blocks of what must be called black 

 serpentine are found there. (No. 890.) 



In giving an account of the limestone found at Newbury, I have 

 mentioned nearly every important circumstance respecting the ser- 

 pentine of the same spot. It occurs there in veins or irregular mass- 

 es of only a few inches diameter. It will be seen by the polished 

 specimens that several varieties at this locality are very beautiful • 

 but they are so intersected by various minerals that only small pieces 

 can be obtained. 



