Cross Lake Project (1983-86)


Geologist    P.G. Lenton     Year    83     STATION    5079
EASTING   572171     NORTHING   6039270     ZONE   14     DATUM   NAD83
Date of mapping    06/27/1983

STRUCTURAL DATA

Planar Structures:
Structure type Strike Dip Separation
schistosity 236 74

Exposed contact of footwall of the gabbro to the west

PETROLOGIC DATA

Rock Number: 1

Rock Type: granodiorite
Descriptors:
porphyritic
leucocratic
augened

Field Description:

-slightly augened porphyritic granitoid

Textural Features
Type Mineral Min. Size Max. Size Abundance (%) Unit
mafic mineral biotite 0.0 0.0 13.0 %
groundmass grainsize 0.5 2.0 mm
phenocryst plagioclase 0.0 0.0

Rock Number: 2

Rock Type: amphibolite
Descriptors:
mafic
volcanic derived
occurs as a raft
ultramafic flow
location is 70% bedrock exposure
possible tuff
1.5 metres wide

Field Description:

-70% of outcrop is complex raft system comprising dominantly ultramafic flows and derived tuffs. In one spot even looks like an ultramafic flow 1.5 m. thick with more felsic 25 cm flow top breccia (if you really stretch your imagination)


Manitoba Geological Survey, 2017