Cross Lake Project (1983-86)

Geologist P.G. Lenton Year 83 STATION 5069
EASTING 571124 NORTHING 6038591 ZONE 14 DATUM NAD83
Date of mapping 06/25/1983

STRUCTURAL DATA

Planar Structures:
Structure type | Strike | Dip | Separation
cataclastic foliation | 56 | 72 |

-complex mafic to intermediate dike sequence

PETROLOGIC DATA

Rock Number: 1

Rock Type: multi-component schlieric gneiss
Descriptors:
complex
tonalitic
granodioritic
Field Description:

-complex tonalitic to granodioritic gneiss sequence much as on north side and in Clearwater Bay

Textural Features
Type | Mineral | Min. Size | Max. Size | Abundance (%) | Unit
mafic mineral | biotite | 0.0 | 0.0 | 4.0 | %

Rock Number: 2

Rock Type: quartz diorite
Descriptors:
beige in color
grey
massive
leucocratic
salt and pepper texture
intrudes rock #1
Field Description:

-extensive areas of coarse salt and pepper beige to white weathering intermediate rock that intruded the MCSG
-quartz 10 to 15 %

Textural Features
Type | Mineral | Min. Size | Max. Size | Abundance (%) | Unit
mafic mineral | hornblende | 0.0 | 0.0 | 12.0 | mm

Minerals of Note
Mineral | Abundance (%)
quartz | 12.0

Rock Number: 3

Rock Type: diorite
Descriptors:
charcoal grey
black
massive
intrudes rock #1
intrudes rock #2
boudin or boudinaged
Field Description:

Many large boudins 1-3 m across by several metres long of mafic, occassionally porphyritic diorite
-Shows obvious intrusive contacts on both rocks 1 and 2
Approximate sequence of events:
1) intrusion of main tonalite
2) extensive tonalitic veining
3) deformation
4) intrusion of quartz diorite (rock #2)
5) intrusion of diorite (rock #3)
6) extensive shearing
7) deformation and folding
8) late shearing and cataclasis

Textural Features
Type | Mineral | Min. Size | Max. Size | Abundance (%) | Unit
mafic mineral | hornblende | 0.0 | 0.0 | 35.0 | %
phenocryst | plagioclase | 0.0 | 0.0 |  |

Manitoba Geological Survey, 2017