SOME PRE-CAMBRfAN LITER ATirRK OF NOR 1 11 AMERICA 463 



Baker"^ stales that the pre-Cambrian rc^cks of the Lower M;i,t- 

 tagami basin arc pink gneisses of Laurentian age, Post-Middle 

 Huronian diabase dikes, a small outcrop of a banded sidcrite, fjuartz 

 conglomerate, and quartzite which may be U])i)er Tfuroni;!,!). 



Baker^ states that the pre-(Jambrian in the Lake Abbitibi area 

 consists of Keewatin schistose, ellipsoidal greenstones, and otiier 

 metamorphosed eruptive rocks infolded with dolomites, graphitic- 

 slates, jaspilites, and fragmental materials, all intruded by Laun-n- 

 tian granites, pegmatites, and granite porj)hyries. Tliis old 

 complex is intruded by post-Huronian quartz diabase, quartz 

 gabbro, and Camj)roi)hyric and a})Iitic flikes. The diabase is 

 associated with veins showing traces of silver and gold, but no 

 important metal depcjsits have thus far been found. 



Baker-^ states that the pre-Cambrian rocks of the Mattagami 

 River region are Laurentian granites and gneisses intruded by 

 diabase dikes, probably Post Middle Huronian in age, Up[)er 

 Huronian siderite, sideritic conglomerate, and quartzite. 



Bancrciff re[)orts the following f)re-C'ambrian formations from 

 the Keekeek and Kewagama Lakes region, 40 miles northeast of 

 Lake Temiskaming. 



Post Huronian — ^dikcs and stocks of basic inLrusivcs probably Kewcenawaii 

 Huronian ( ?J — conglomcraLe, arkose, and graywackc — all schistose 

 Laurentian — balholiths and stocks of granite and syenite 

 Keewatin — basic and acid scliists, iron formation, tuffs, vcjicanic breccias, 



rhyolites, Ijasalts, basic and acid extrusives 



iiurr<;ws' states that the South l^orrain silver area is nortfi of the 

 Montreal River and west of Lake Temiskaming, and about 16 miles 

 southeast of the Cofjalt district. The pre-Cam};rian rocks are 

 Keewatin, basic igneous rocks, and minor acid intrusives, intruded 



' M. IJ. Bilker, " [row and Lij^nitc in l.hc Miil.l.agami Hasin," OnL /iiir. Mines, 2olh 

 Ann. Kepi., j)p. 214-46, 37 figs. 



^ M. \i. Baker, "Lake Abbitibi Area," Onl. Bur. of Mines, iHlh Ann. RepL, 

 XVIII (1909), 263-83, pi. I, 9 figs. 



3 M. B. Baker, "The Iron Ores of the Mattagami River," Jour. Can. Min. Inst., 

 XIV, 299-309. 



4 J. Austin Bancroft, "Report on the (ieology and Mineral Resources of Keekeek 

 and Kewagama Lakes Region," Province of (2u(ihec, hjji, i)[). 160. 



5 "South r^orrain Silver Area," Onl. Hur. Mines, iHlli Ann. Kept. iujoH) pi. 2, 

 pp. 21-31, 1909. 



