50 
FIFTEENTH REPORT. 
Another specimen shows a grain of calcite 0.5 mm. in diameter, which 
wholly or partially enclosed twenty ragged grains of gold. The gold is 
irregularly scattered through the calcite, but it is mostly at the edges. 
The calcite is surrounded by tine quartz 0.05 mm. in diameter. 
5. Gold among grains of finely crystalline quartz, e.g. One very 
irregular area of gold, 1 mm. long and varying in width from 0.02 to 
0.1 mm. is almost completely enclosed by fine grained quartz, the par- 
ticles of which average 0.03 mm. in diameter. That part of the gold, 
not enclosed by quartz, is in contact with calcite. It is noteworthy that 
most sections, showing gold, show also fine (probably granulated) 
quartz and small amounts of calcite. 
CHARACTERISTICS OF THE WALL ROCKS. 
The gold quartz occurs in rocks of the Keewatin and Huronian series. 
The Keewatin is composed largely of igneous with some sedimentary 
rocks. The Huronian is largely sedimentary. Most of the deposits are 
in altered quartz porphyry, others in more basic rocks — porphyrites, 
basalts, etc. — conveniently called greenstones. Some are in conglomerate 
and greywacke-slate. 
Mr. A. G. Burrows, who has mapped the area for the Ontario Bureau 
of Mines, gives the following succession of formations for the district: 
“ Pleistocene . — Post Glacial— stratified clay, sand and peat. 
Glacial — boulder clay. 
Pre-Cambrian. — Later Intrnsives — quartz-diabase, olivine, diabase, etc. 
Igneous contact : 
Cobalt Series — conglomerate. 
Unconformity : 
Temiskaming Series — conglomerate, greywacke, quartzite, slate or deli- 
cately banded greywacke. 
Unconformity : 
Laurentian — A complex of granites older than the Cobalt series. Tt 
intrudes the Keewatin, but its relationship to the 
Temiskaming is not definitely known; it may be in part 
older and in part younger than the Temiskaming series. 
Tgneous contact: 
Keewatin — The series consists chiefly of basic to acid volcanics, much 
decomposed, and generally schistose; amygdaloid basalts, 
serpentine, diabase, quartz or feldspar porphyry, felsite. 
iron formation, rusty weathering carbonates, and other 
rocks have been recognized.” 
The Cobalt and Temiskaming Series referred to by Mr. Burrows are 
divisions of the Huronian corresponding to those made by Hr. W. G. 
Miller at Cobalt and by Mi*. Robert Harvie 2 in the area east of Lake 
Temiskaming. Mr. Harvie calls the lower sediments “the Fabre series.” 
The gold is found in quartz occurring in the several types of rock com- 
prising the Keewatin and Temiskaming series, but it is noteworthy that 
the wall rocks of all the ore bodies, while probably originally quite 
different, have remarkably similar composition. This similarity is due 
to alteration, by which the minerals have l>een replaced by sericite, car- 
2 Geology of a portion of Fabre Township, Quebec Mines Branch, 1911. 
