420 V. P. MARSTERS — ASBESTOS DEPOSITS OF BELVIDERE MOUNTAIN 



Page 



Local variations 438 



Garnet zone 438 



Development of anthophyllite 439 



Serpentine 439 



Criteria for determining origin 439 



Micro-structure of Belvidere serpentine 440 



Types 440 



Fibrous serpentine 440 



Lamellar and bastite serpentine 441 



Discussion as to origin 441 



Contact phenomena 441 



Applications of Emerson's views 442 



Analyses of type rocks and fiber 443 



Conclusions ... 445 



Early Views on the Stratigraphy of Vermont 



The occurrence of serpentine and associated minerals was early known 

 to the pioneer geologists of Vermont. In the report prepared by Pro- 

 fessor Edward Hitchcock and his co-workers (1861) frequent mention is 

 made of them, and it is stated that in many instances more or less as- 

 bestos and talc, in several varietal forms, are to be found. While con- 

 siderable preliminary prospecting was carried on in the early seventies, no 

 industry of any moment was established until a comparatively late date. 



According to the observations of Professor Hitchcock, the serpentine 

 formations are very largely confined to a broad band of so-called talcose 

 schists which enters Vermont on the north in Orleans county. At the 

 northern boundary of the state the schist belt has a maximum width of 

 some 15 miles, with its eastern limit near the western shore of lake 

 Memphramagog. This series of metamorphics is shown on his map as 

 extending the entire length of the state and occupying portions of Orleans, 

 Lamoille, Washington, Addison, Orange, Windsor, and Windham coun- 

 ties and having a minimum width at the southern boundary of the state 

 of some 2h miles. While some ten occurrences of serpentine are reported 

 to exist in the southern half of the talcose belt, by far the largest of these 

 deposits is located in Orleans and Lamoille counties. It is very probable 

 that this serpentine and the associated schists belong to the same group 

 as those of the Thetford region. The schists are regarded by the Canadian 

 Geological Survey as Cambrian in age. 



Location of Belvidere and Lowell Areas 



The small area under consideration in this paper lies within the adjoin- 

 ng townships of Eden, in Lamoille, and Lowell, in Orleans county. 



