JOGIBILIUCAL IHOUN S, Dat 
Low‘ describes the Archean of Portneuf, Quebec and Montmorency 
counties in Quebec. These rocks cover about 980 square miles, and 
are covered on the south by Cambro-Silurian limestones and shales. 
A rough section from west to east across the northern_portion at right 
angles to the strike through lake Simon is as follows: 
(1) Dark schistose mica-gneiss, interbanded with coarser red and 
gray mica-gneisses. 10 miles. 
(2) Fine-banded gray, pink and red mica-gneisses, and mica- 
hornblende-gneisses. ro miles. 
(3) Dark gray garnetiferous hornblende-gneiss. 2 miles. 
(4) Fine-banded gray, pink and red mica-gneisses and mica- 
hornblende-gneisses. 7% miles. 
(5) Dark green basic, crushed granitic gneiss. 1% miles. 
(6) Coarse red and gray augen-gneiss. 2% miles. 
(7) Fine-banded gneiss (2) and (4). 6 miles. 
(8) Coarse red and gray augen-gneiss. 6 miles. 
(9) Fine-banded gray and pink mica-gneiss. 14 miles. 
(10) Anorthosite. 2 miles. 
(tr) Fine-banded, gray and pink gneisses. 12 miles. 
In this section the rocks are grouped in accordance with the pre- 
dominating kind, although bands of other varieties are included in all 
of the rough divisions. Divisions 1, 2, 3, 4, 9 and 11 appear to have 
been originally clastic rocks, subsequently completely metamorphosed 
into schists and gneisses, and subjected to great pressures, which have 
folded and twisted them so that their original horizontal succession is 
greatly obscured. ‘The different bands are conformable and appear to 
grade into one another. ‘The 5th division embraces rocks probably of 
igneous origin, which have been injected along a line of weakness 
between the banded gneisses and the coarser-grained rocks of the 6th 
division. The 6th and 8th divisions are usually gneissic, but often are 
granitic. They appear to underlie the banded gneisses, and are either 
the remains of older beds that have been re-fused or are original 
molten matter which has dissolved and floated portions of the banded 
beds, since fragments of them are enclosed in the coarser gneisses. 
The anorthosite is also igneous, having apparently been intruded in its 
present position after the formation of the banded gneiss with which 
‘Report on the Geology and Economic Minerals of the Southern Portion of Port- 
neuf, Quebec and Montmorency Counties, Province of Quebec, by A. B. Low. Ann. 
Rep. Geol. Sur. of Canada for 1890-91, Vol. V., Part 1, L, pp. 5-82, 1892. 
