ELIZACETIITOWN AND PORT IIEXRY OUAIJRAA' GLES 1 ^^CJ 



The ore occurs in a moderately large mass of gabbro which can 

 be traced in the vicinity. It is a dark green or black rock, con- 

 sisting of augite, hypersthene, brown hornblende, garnet, original 

 basic plagioclase, charged with pyroxenic dust and minute spinels, 

 secondary plagioclase in clear rims around the last named, and of 

 the magnetite-ilmenite mixture. The ore is lo feet or more thick, 

 and forms a flattened body, which strikes into the hill n. 7o°-8o° e. 

 and dips 50° south. An open cut has been- excavated 30-40 

 feet deep and 25 feet high. From its mouth the old dump of 

 broken ore streams like a talus down to the lake shore. To the 

 south another small opening is reported but this has not been vis- 

 ited by the writer. 



AVhile- the rock mass is faintly foliated from dynamic effects, 

 there is no sharp transition from ore to rock. The former is 

 simply a basic phase of the latter and the exposures are so good 

 that this locality is a specially favorable one for the studj of the 

 relations. 



In cracks through the ore a curious isotropic green substance is 

 somewhat rarely found which contains some dusty magnetite and 

 the decomposed remains of feldspar crystals. It has been pre- 

 viously described by the writer as a glass, but its identity can not 

 be sharply determined without a cjuantitative chemical analysis. 

 Its specific gravity is 2.822 which is higher than the common iso- 

 tropic minerals which might occur in these relations. 



An analysis of the wall rock has been made by W. F. Hillebrand 

 and also one of the ore, nos. i and 2 below. No. 3 is an analysis 

 by George W. Maynard, made in the early seventies. Nos. i and 

 2 are from the 19th Annual Report of the United States Geological 

 Survey, volume 3, page 402 ; no. 3, Journal of the British Iron 

 and Steel Institute, volume i, 1874. 



I 2 3 



SiO. 47.88 I7-90 16.46 



TiOa 1-20 15-66 14-70 



Cr^Oa tr. ? .51 



AI2O3 18 . 90 10 . 23 -34 



Fe.Os 139 15-85 38-43 



FeO 10-45 27.94 23.40 



NiO.CoO .02' not det. not det. 



MnO -16 tr. .23 



MgO 7-10 6.04 2.13 



CaO 8.36 2.86 3-54 



SrO tr. 



BaO tr. 



