emerson's scheme of metamorphism 443 



Original rock. First stage. Second stage. 1'hird stage. 



Pyroxenite Sahlite serpen- Serpentine Talc, 



limestone. tine (tremolite). (steatite). 



Enstatite Enstatite serpen- Serpentine. Talc. 



Ferruginous '-«*»»• gS^E™* 



aud lite >- 



. -n m „ Amphibole Amphibolite Serpentine. Talc. 



Aigillaceous limestone. (epidote). 



limestones. TremQlite _ Talc . 



limestone. 



Olivine serpen- Serpentine Talc, 



tine (tremolite). (asbestos). 



At the present stage of investigation of the Belvidere region it can 

 only be said that neither the amphibolite nor the serpentine has been 

 found in association with limestones or highly calcareous rocks of any 

 sort which would in any respect show an analogy with the occurrences 

 in Old Hampshire county, Massachusetts. 



Analyses of Type Rocks and Fiber 



An inspection of the following analyses and comparison with those of 

 chrysotile from the Canadian area bring out some significant facts. 



Number Si0 2 A1 2 3 Fe 2 3 FeO MgO H 2 CaO Total 



45 41.84 2.23 41.99 14.28 .... 100.34 



48 40.57 0.90 .... 2.8L 41.50 13 55 .... 99.33 



49 40.52 2.10 .... • 1.97 42.05 13.46 .... 100.50 



1 39.97 7.27 .... 40.78 12.51 0.50 101.03 



2 44.10 43.00 12.90 .... 100.00 



Numbers 45, 48, and 49 are analyses of chrysotile from Shipton, Quebec, Brough- 

 ton, and Templeton, and are selected from a series in Dana's Systematic Mineral- 

 ogy, page 673. 



Number 1. Belvidere chrysotile (cross-fiber) from the Tucker prospect; analysis 

 by Mr C. H. Jones, Burlington, Vermont. Both the oxides of iron and the alumi- 

 num are included under the 7.27 per cent. 



Number 2. Theoretical composition of chrysotile, as given in Dana's Systematic 

 Mineralogy, page 671. 



In the Belvidere fiber number 1 it will be noted that the silica runs 

 somewhat lower than is indicated in the Canadian cases and considerably 

 lower than the theoretical limit, while the total alumina and iron is, on 

 the other hand, much higher than in numbers 45, 48, and 49. The iron 

 is probably somewhat high, for the reason that the fiber contains micro- 

 scopic grains of magnetite tucked away between the films to such an 



LX— Bull. Geol. Soc. Am., Vol. 16, 1904 



