6 4 



The acid intrusives of the Keewatin are on the whole 

 younger than those of more basic composition. Certain 

 diabases are intrusive into the basalts and iron formation. 



No granite, or granite gneiss, older than the Lorrain 

 granite, occurs in the immediate vicinity of Cobalt, but 

 certain pebbles and boulders in the conglomerates of the 

 silver area have been derived from the Laurentian. 



The name Laurentian is applied to granite or granite 

 gneiss, typically of grey color, the gneiss frequently poss- 

 essing alternate dark and light colored bands. The well- 

 banded gneiss owes its composition and structure to the in- 

 clusion of fragments and masses of Keewatin in the intrus- 

 ive granite, which have been squeezed or drawn out. 



The Laurentian intrudes both the Keewatin and the 

 Grenville series. The Temiskaming is the oldest fragmental 

 series known in the region that is of post-Laurentian age. 



THE TEMISKAMING SERIES 



The Temiskaming series is composed of conglomerates, 

 greywackes and slates. The conglomerates show a great 

 variety of pebbles, including the following: basalt, diabase, 

 green schist, pyroxene or hornblende-porphyry, quartz- 

 porphyry, feldspar-porphyry, felsite, jaspilyte, grey, white 

 and red cherts, grey granite, granite gneiss and coarse 

 porphyritic syenite with crystals of feldspar one-half to one 

 inch in length. 



The Temiskaming series is generally distinctly bedded, 

 and the strata are everywhere seen to have been tilted up 

 until they now rest in a vertical, or almost vertical, attitude. 

 Cross-bedding has been noted in some of the greywackes. 

 Along the shores of lake Temiskaming, between Haileybury 

 and New Liskeard, the strike ,4s easterly, observations) 

 giving strikes of N. 60 degrees to 70 degrees E., and steep 

 dips to the south. At the northwest corner of lot 8, in the 

 second concession of Bucke, the strike is N. 20 degrees W., 

 with steep dips to the east. In various places the series is 

 intersected by quartz stringers a few inches in width and a 

 foot or more in length. 



An unconformity is inferred to exist between the Lauren- 

 tian granites and gneisses and the Temiskaming sediments, 

 because granite, syenite and granite gneiss pebbles are found 

 in these sediments. 



