Cross Lake Project (1983-86)

Geologist P.G. Lenton Year 83 STATION 5073
EASTING 571996 NORTHING 6041763 ZONE 14 DATUM NAD83
Date of mapping 06/26/1983

STRUCTURAL DATA

Planar Structures:
Structure type | Strike | Dip | Separation
schistosity | 89 | 75 |

PETROLOGIC DATA

Rock Number: 1

Rock Type: tonalite
Descriptors:
schlieric or schlieren present
leucocratic
Field Description:

-Minor component of megacrystic granodiorite.
Unusual feature:
Because of less deformation and shearing here there are preserved blocky blue-grey an pink microcline megacrysts upto 20 cm floating in the tonalite. They are not dike or pegamtite related and don't appear to be structural features such as boudins. I can see no explanation for these other than magmatic megacrysts.

Textural Features
Type | Mineral | Min. Size | Max. Size | Abundance (%) | Unit
phenocryst | potassium feldspar | 0.0 | 20.0 |  | cm

Minerals of Note
Mineral | Abundance (%)
biotite
garnet

Rock Number: 2

Rock Type: amphibolite
Descriptors:
layered
hornblende-epidote bearing
occurs as a raft
Field Description:

-many large rafts of highly folded mafic amphibolite.
-contains large deformed pods with hornblende-epidote rims and webwork of white quartz through a core of pale orange carbonate mineral - could be siderite - sample 2B carbonates for x-ray I.D.

Minerals of Note
Mineral | Abundance (%)
garnet

Rock Number: 3

Rock Type: pegmatite
Descriptors:
granitic
aplitic
dike
Field Description:

-Pegmatite and aplite dike swarms. Samples of aplite.
-Varicolored blocky microcline in grey quartz.
-Biotite only mafic.
-Garnet most abundant in quartz-poor margins.

Minerals of Note
Mineral | Abundance (%)
garnet
biotite

Manitoba Geological Survey, 2017