Cross Lake Project (1983-86)

Geologist P.G. Lenton Year 85 STATION 6002
EASTING 576287 NORTHING 6045630 ZONE 14 DATUM NAD83
Date of mapping 06/07/1985

STRUCTURAL DATA

Planar Structures:
Structure type | Strike | Dip | Separation
schistosity | 306 | 56 |
fracture cleavage | 244 | 74 |

-PHOTOS
1,2,3 relationship of grey porphyry to pink granite-mylonite contact
4 general of contact with amph.

PETROLOGIC DATA

Rock Number: 1

Rock Type: amphibolite
Descriptors:
massive
volcanic derived
Field Description:

-Greenish black Ampb with strong SC
-probably largely cataclastic
-layering not apparent, although scattered feldspathic knots up to 1 cm that may have been feldspar phenocrysts
-probably massive basalt or plag. pheric basalt

Rock Number: 2

Rock Type: granite
Descriptors:
porphyritic
microcline - biotite bearing
Field Description:

-mottled grey and beige, averages 30 % quartz with variable 20 to 35 % subhedral MC phenocrysts ranging from 3 to 7 mm. Biotite, only mafic, seems to contain traces of MG and rare pale violet FL.
-Extensively layered with rocks three and four. Cataclase has largely obscured the relationships but rock four appears to be younger.

Minerals of Note
Mineral | Abundance (%)
fluorite

Rock Number: 3

Rock Type: granite
Descriptors:
aplitic
leucocratic
Field Description:

-Approximately 3 m, massive fine grained slightly porphyritic granite. Occurs at contact with ampb.
-this may be a chill, possibly of rock type 2 although it is considerably more leucocratic.
-there appears to be a gradational relationship between them.

Rock Number: 4

Rock Type: granite
Descriptors:
gneissic
leucocratic
Field Description:

-pink weathering, slightly cataclastic ranging to augen granite. -35% quartz
-trace of MG
-appears to be the major unit occuring throughout middle of Spod. Bay.
-has typical mottled pink and white colour with microcline Fe stained.
-relationship appears to intrude grey porphyry although contacts commonly mylonitic. No visible FL.
-interlayering with rock type 2 decreases to the south and pink granite becomes dominate rock type within 75 m of Ampb

Manitoba Geological Survey, 2017