Annual report . ilway,states that a little farther down stream he observed a basic looking rock in the bed Rep. Ont. Bur. Min., Vol VIIl 1899, page 184. Bureau of Mines No. 4 of the river. This rock was seen when the water was very low; a specimen of thefloat picked up on the river bank showed it to be a highly altered gabbro ( ?). Generally speaking, the rocks at the head of Lobstick portage, represented bybiotite, and augite-syenite gneisses, with occasionally the more massive and acidicfacies, pass gradually by differentiation, into the typical gabbro observed in theCanyon. Mattagami Basin,
Annual report . ilway,states that a little farther down stream he observed a basic looking rock in the bed Rep. Ont. Bur. Min., Vol VIIl 1899, page 184. Bureau of Mines No. 4 of the river. This rock was seen when the water was very low; a specimen of thefloat picked up on the river bank showed it to be a highly altered gabbro ( ?). Generally speaking, the rocks at the head of Lobstick portage, represented bybiotite, and augite-syenite gneisses, with occasionally the more massive and acidicfacies, pass gradually by differentiation, into the typical gabbro observed in theCanyon. Mattagami Basin, Railway to Paleozoic Sediments The Groundhog river, a tributary of the Mattagami, joins the latter at adistance of about thirty-five miles north of the National railw^ay. The rock ex-posures along the Groundliog and Mattagami rivers are much more numerous thanon the Abitibi river. The exposures consist largely of hornblende, and biotite-granite gneiss, until about the junction of the Kapuskasing river. From the. Mattagami river, below the Lono- portage. At the point on the bank of the river to theright of the small island is an oociurence of lire clay of good quality. junction with the Kapuskasing to tbe head of Little Long portage the rocks assumeii more basic character, hornblende giving place to biotite. The feldspar isgreenish in colour, and is ai)])arently a plagioclase variety; quartz is subordinate inamount. The gneissic structure is highly developed, and in places is schistose,particularly in the vicinity of Devils portage. At the head of Little Longportage the gneiss becomes highly garnetiferous, these garnetiferous biotite-gneissescontinuing to the foot of Long portage, where the last pre-Cambrian exposure wasobserved. About fifteen miles below the foot of Long portage, the Paleozoic sedi-ments were encountered: these consisted of an outcropping of oil shale and greenshales. Four and one-half miles below this point, at the head of Grand rapids, theCorniferous limesto
Size: 2092px × 1194px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1890, booksubjectminesandmineralresou
