64 PROCEEDINGS OF THE CANADIAN INSTITUTE. 



MiNERALOGICAL NoTES ON SuDBURY ANTHRACITE. By G. R. MiCKLE, B.A. 



(Read February 27, 1897.) 



On the map of the Sudbury District, pubhshed by the Geological Survey De- 

 partment, an oval area about 8 miles wide and 30 miles long vi^ill' be observed. 

 This oval area is mad*e up of a central part of " dark argillaceous and gritty sand- 

 stones " and a border of " blackish, siliceous volcanic breccia and black slate in 

 places." The rocks found in this area are possibly Cambrian, but no fossils have 

 been found to determine the age definitely. The deposit, or vein, vi^hich will be 

 here described, is in the border. Another deposit or vein has been found about five 

 miles further west, near the shore of Vermillion Lake. 



The writer's attention was first called to this occurrence of coal-like substance 

 early in June last year, when he made some preliminary tests on this peculiar min- 

 eral, which showed that it acted like anthracite. Shortly after this the surface soil 

 was stripped off, and when visited by the writer, early in July, there was a consid- 

 erable quantity of this mineral in sight. During the summer the vein was uncovered 

 for about 70 feet, the average width being probably about 9 feet. The strike is about 

 N. 20 degrees W., and the dip apparently about 45 degrees to E. Intermixed with 

 the coal there is in places a considerable amount of quartz, and occasionally a little 

 iron pyrites. The quartz forms, sometimes, a network, in which rectangular frag- 

 ments of coal are imbedded; in other places the coal is almost free from quartz. 

 If one of these rectangular fragments is partially burnt, and then examined by a 

 glass, minute veins of quartz can be seen traversing it. 



The mineral has a lustre like anthracite, only higher. Its hardness is between 

 3 and 4. This is considerably harder than ordinary anthracite, which is given as 

 2 — 2.5. The specific gravity, as determined by Mr. Lawson, -s 1.865, the specific 

 gravity of anthracite being 1.4 — 1.7; the average of ten commercial samples from the 

 western middle coal fields of Pennsylvania was found to be 1.658 ; from the other 

 coal fields of that State it was less (Penn. Geol. Survey, 1895, p. 1929). Some 

 Rhode Island anthracite has specific gravity 1.81 (Dana). A mineral closely 

 resembling this one was found in the Huronian formation near Lake Onega, in 

 Russia. The lustre is described as adamantine metallic ; hardness, 3.5-4 ; specific 

 gravity, 1.84, and chemical composition similar to the Sudbury mineral (Naumann 

 Mineralogie). The hardness and specific gravity of this interesting mineral from 

 Sudbury are, therefore, on the extreme outer limit of anthracite. Another coal-like 

 substanc^e, which is shown in the sketch, is classed by Mr. Miller, of Kingston, as 

 anthraxolite. Mr. Miller says: "The anthraxolite which I sent was collected by 

 me ' in situ,' about six miles north of this city. It occurs in a vein which has 

 been worked for barite on the farm of John Woodruff, the north part of lots 16 

 and 17, in fourth concession of the Township of Kingston. The vein, which is 

 nearly vertical, is about 2 1-2 feet wide, and cuts the limestone of the Black River 

 formation of the Silurian system. This limestone is very fine grained, and litho- 

 graphic in character, and forms a comparatively thin layer over the Laurentian 

 gneiss, which is exposed at places in the valleys. The most abundant mineral in 

 the vein is barite, but calcite and fluorite are also found, as well as anthraxolite 

 This vein can be traced across country for over one and a half miles in the 

 limestone ; it is, however, not found in the valleys where gneiss is exposed. 



The anthraxolite has been deposited after the barite and other minerals, as it 

 •coats them and fills crevices in them. It is probable it has been derived from the 



