212 RECORD OF SCIENCE FOR 1886. 



Bay than iu the Labrador peninsula or north of Hudson's Strait. The 

 same author, in a paper on the mineral resources of the Hudson's Bay 

 Territory, states that on the eastern shore of the bay there occurs a 

 series of sedimentary rocks apparently identical with the Animikieand 

 Nipigon groups. On the western and northwestern shores there are 

 altered rocks resembling the gold bearing series of Nova Scotia, some 

 similar to the Huronian of Lake Huron, and others like the crystalline 

 series near Cherbourg, Quebec. Between the Laureutian nucleus and 

 the Rocky Mountains there is a great basin of Silurian, Devonian, Cre- 

 taceous, and Tertiary rocks, which give place northward to limestones, 

 probably of Mpigon age. On the shores of the Arctic Ocean similar 

 limestones, associated with traps, are the prevailiug rocks between 

 Mackenzie and Coppermine Rivers, and the copper-bearing rocks of the 

 latter region appear to correspond with those of the Lake Superior dis- 

 trict.* 



69. Willis, in a report on a trip to the Upper Mississippi and Vermil- 

 lion Lake, Minnesota, describes some structural relations of the Vermil- 

 lion Lake iron-bearing series, the supposed northern equivalent of those 

 of Marquette. The beds are all vertical, and pressed into close folds with 

 exceedingly intricate relations. The iron-bearing bed is of jasper, hold- 

 ing non-magnetic specular ore, and is associated with semi-crystalline 

 schistose rocks and a bed of quartzite containing grains of magnetite. 

 The Vermillion and Two River ranges are thought to be anticlinal 

 ridges, eroded down to the chloritic schists. Some of the structural 

 features are very curious, and the relations under one swampy area were 

 worked out by tracing the magnetite-bearing quartzite with the mag- 

 netic needle.t 



70. Britton's report (already referred to) is a preliminary account of 

 the continuation of Smock's studies of the Highland Archean for the 

 New Jersey Geological Survey. Smock's discovery that the crystalline 

 rocks could be divided into "massive" and " bedded " was taken up, 

 and the areal and structural relations of each worked out for a portion of 

 the district. The massive and underlying rocks consist in the main of 

 quartz, syenites, grauulites, and hornblendic granulites, and graduate 

 into the stratified rocks, which are gneisses, hornblendic schists, etc., 

 but all are considered equivalent to the Laurentian in age. The struc- 

 tural relations are not particularly complicated so fir as determined, 

 and the eastern side of the Highlands appears to have been more over- 

 turned than the western. | 



71. Farther northward, in the Highlands in New York, Ruttman gives 

 an account of a detailed study of the Tillie Foster magnetite deposit. 



* Canada, Geol. Survey, Report for 1885, DD., and Am. Inst. Mining Engs., Trans., 

 1886. 



+ Tenth Census, Report on Mining Industries, pp. 457-467. 



t Geological Survey of New Jersey, Annual Report of the State Geologist for 1885, 

 pp. 36-55. 



