Cross Lake Project (1983-86)


Geologist    P.G. Lenton     Year    83     STATION    5100
EASTING   573701     NORTHING   6040462     ZONE   14     DATUM   NAD83
Date of mapping    07/08/1983

STRUCTURAL DATA

Planar Structures:
Structure type Strike Dip Separation
cataclastic foliation 79 69

PETROLOGIC DATA

Rock Number: 1

Rock Type: two component schlieric gneiss - intimate mixture of 2 major units
Descriptors:
cataclastic

Field Description:

-Typical of the old granodiorite in zone of extreme compression
-reduced to coarse hornblende-bearing augen gneiss
- plagioclase highly sericitized.
-one unusual aspect is that quartz is random in homogeneous distribution with no tendency to segregate in the foliation plane

Minerals of Note
Mineral Abundance (%)
hornblende

Rock Number: 2

Rock Type: amphibolite
Descriptors:
layered
hornblende - diopside bearing

Field Description:

-much more diversified assemblage of rock type.
-layered sedimentary amphibolites are much more common
-breccia zones of massive black hornblendite occur in 2 locations
-massive volcanic ampb is commonly reduced to epidosite

Rock Number: 3

Rock Type: granodiorite
Descriptors:
porphyritic
biotite

Field Description:

-boudins of younger grey granodiorite completely dismembered in the foliation plane but as usual does not show an extensive history of intrusion and deformation
-phenocrysts granulated and ghostly

Textural Features
Type Mineral Min. Size Max. Size Abundance (%) Unit
groundmass grainsize 0.0 5.0 mm
mafic mineral biotite 0.0 0.0 18.0 %


Manitoba Geological Survey, 2017