The Long Labrador Trail Part 22

11--Phyllite--same location as No. 9.

A dark red, finely laminated rock consisting chiefly of decomposed biot.i.te and feldspar, occasional quartz grains and sericite and much iron oxide.

The rock has been subjected to strong shearing force, producing a good example of schistose structure.

12--Quartzite--Same location as No. 9.

A compact rock of light red color, made up of uniformly rounded grains of quartz, and the feldspar with occasional grain of magnet.i.te.

A fine siliceous material discolored by iron oxide, acts as a cement between the grains.

The quartz grains show secondary growth. 13--Altered Gabbro--Thirty-two Miles Above Wuchusk Nipi on Nascaupee River.

A coa.r.s.e dark green rock whose princ.i.p.al const.i.tuents are pyroxene plagioclase and magnet.i.te.

There is a slightly developed diabasic structure and the rock is much altered by weathering; the resultant product being chlorite.

14--Quartizite--Bibiquagin Lake.

Hard compact rock of light red color, cut in all directions by narrow veins of quartz, from microscope size to one-half an inch in width.

The grains of the const.i.tuent minerals, quartz, feldspar and magnet.i.te have an angular brecciated appearance; showing uneven extinction and strong crus.h.i.+ng effects.

The magnet.i.te is somewhat decomposed, the resulting hemat.i.te filling the s.p.a.ces between the quartz grains.

15--Anorthosite--Sh.o.r.e of Lake Michikamau.

A coa.r.s.e grained rock of dark gray color, in which labradorite is the chief mineral. Magnet.i.te and Kaolin are present in small quant.i.ties.

The labradorite contains inclusions of rutile and biot.i.te and has a well-developed wedge structure and cross fracture due to the pressure and shearing which it has undergone.

It is also somewhat stained by the decomposition of the magnet.i.te.

SOURCES OF INFORMATION

On the map of the portage route to Lake Michikamau; that lake, the Grand River and Groswater Bay are taken from the map accompanying the report of Mr. A. P. Low.

The location of the Susan and Beaver Rivers with their tributaries was obtained from Dillon Wallace's map in "The Lure of the Labrador Wild."

The instruments used were a Brunton Pocket Transit, a small taffrail log and an Aneroid Barometer. Distances on land were approximated by means of a pedometer and by rough triangulation.