96 NEW YORK STATE MUSEUM 



Minor intriisives, cutting all the above masses, occur as bosses 

 or dikes of gabbro, pegmatite, or diabase. 



An important structural feature is the presence of numerous 

 normal faults Avhich have greatly dissected the region. 



DESCRIPTION OF THE GARNET DEPOSITS 

 There are at least seven localities in Warren county where gar- 

 net mining has been carried on as follows: (i) Rogers (Bar- 

 ton) mine- near the top of Gore mountain and three and one-half 

 miles west-southwest of North Creek ; (2) near the top of Oven 

 mountain and four miles south of North Creek; (3) the Rexford 

 mine, one and one-third mileS a little east of south of North 

 Creek; (4) the Parker mine just southwest of Daggett pond and 

 four and one-half miles northAvest of Warrensburg; (5) the San- 

 ders Brothers mine near the niouth of Mill Creek and two miles 

 east of Wevertown ; (6) two and three-fourths miles north of 

 North Creek; and (7) the Hooper mine just east of the northern 

 portion of Thirteenth lake. Of these, only the Rogers, Sanders 

 Brothers, and Hooper mines are now in operation. The Rogers 

 and Hooper mines lie within the Thirteenth Lake quadrangle and 

 the others within the North Creek quadrangle. All the above mines 

 have been visited by the writer. 



I In the Rogers mine the mode of occurrence and the size of 

 the garnets are of unusual interest. The matrix or rock carrying 

 the garnets is a gray, medium grained gneiss which, in thin sec- 

 tion, show^s : 20 per cent orthoclase ; 20 per cent labradorite ; 40 

 per cent hornblende ; 15 per cent hypersthene ; 3 per cent biotite ; 

 together with a little magnetite and zoisite. Imbedded in this 

 gray matrix are numerous, well-scattered, translucent, reddish- 

 brown garnets, those with diameters up to five or six inches being 

 very common, while the largest ones taken out are said to have 

 been about the size of a bushel basket. These garnets, Avhich 

 are of the almandite variety, are always pretty badly crushed or 

 coarsely granulated and they never show crystal outlines. 



A remarkable feature is the never failing occurrence of a rim 

 or envelop of pure, black, medium grained hornblende crystals 

 which completely inclose each garnet. Occasionally a half inch 



1 This is called Moore's mine on the topographic map. 



