Cross Lake Project (1983-86)


Geologist    P.G. Lenton     Year    84     STATION    5531
EASTING   568909     NORTHING   6053538     ZONE   14     DATUM   NAD83
Date of mapping    07/03/1984

STRUCTURAL DATA

Planar Structures:
Structure type Strike Dip Separation
cataclastic foliation 243 68

PETROLOGIC DATA

Rock Number: 1

Rock Type: gneiss
Descriptors:
MLNT

Field Description:

-shore line along this section is 65% intrusive and 35% GRCK
-lots of pelite and semi-pelite with subordinate psammite
-highly garnetiferous
-shearing is so intense that granite, pegmatite and GRDR lit are largely homogenized into seds. resulting in a mylonitic schlieric gneiss
-pelite is preferentially invaded
-numerous rusty gossans

Minerals of Note
Mineral Abundance (%)
garnet

Rock Number: 2

Rock Type: granite
Descriptors:
porphyritic
muscovite microcline

Field Description:

-LARGE SAMPLE FOR ANALYSIS

-microcline porphyritic 2 mica granite as dikes parallel to foliation upto 1.5 m thick and down to cm size lit
-large dikes sheared but not as much as seds.
-small veins are augened
-possible candidate for young batholith source
-analysis may tell

Rock Number: 3

Rock Type: gabbro
Descriptors:
schistose
hornblende bearing

Field Description:

-old gabbro dike parallel to cataclasis
-it is extensivly sheared, recrystallized and altered
-around 5 m exposed as south side of narrow swampy break in outcrop
-could be as much as 25 or 30 m max.

Rock Number: 4

Rock Type: granodiorite
Descriptors:
massive
biotite

Field Description:

-grey homo-equi fine grained GRDR similar to youngest unit in CWB complex
-<1% of dikes are this material


Manitoba Geological Survey, 2017