Cross Lake Project (1983-86)

Geologist P.G. Lenton Year 83 STATION 5001
EASTING 571846 NORTHING 6046645 ZONE 14 DATUM NAD83
Date of mapping 06/17/1983

STRUCTURAL DATA

Layering:
Layering type | Strike | Dip | top Direction
bedding | 286 | 71 | N

Planar Structures:
Structure type | Strike | Dip | Separation
schistosity | 286 | 71 |

Dikes and Sills:
Rock Number | Type | Width (m) | Strike | Dip
0 | pegmatite | 0.20 | 208 | 76

-slightly sheared quartz poor pegmatite
-photos bedding in gr. greywacke
-deformed, some boudinage 20 cm

PETROLOGIC DATA

Rock Number: 1

Rock Type: greywacke
Descriptors:
bedded
psammite
faser kiesel (sillimanite-quartz knots) present
parallel laminated
graded bedding present
Field Description:

-Dominantly graded and parallel laminae layers with minor ripple layers.
-No E division numerous faserkiesel in semi pelite layers.
-Minor 10-30cm amphibolite layers
Turbidite

Textural Features
Type | Mineral | Min. Size | Max. Size | Abundance (%) | Unit
faser kiesel | sillimanite | 1.0 | 10.0 | 4.0 | cm
groundmass grainsize |  | 0.0 | 0.5 |  | mm
bedding thickness |  | 1.0 | 10.0 |  | cm

Minerals of Note
Mineral | Abundance (%)
garnet
sillimanite

Rock Number: 2

Rock Type: wacke
Descriptors:
laminated
mafic
Field Description:

-As at 1st stop an amphibolitic wacke/tuff mixture.
-Mainly to south of greywacke

Textural Features
Type | Mineral | Min. Size | Max. Size | Abundance (%) | Unit
mafic mineral | hornblende | 0.0 | 0.0 | 30.0 |
groundmass grainsize |  | 0.0 | 0.2 |  | mm

Minerals of Note
Mineral | Abundance (%)
hornblende
garnet

Rock Number: 3

Rock Type: aplite
Descriptors:
massive
granitic
dike
Field Description:

-Bright pink with a glassy look
-numerous dikes parallel to contact with granodiorite; range from 5 cm to 1 m in thickness
-scattered potassium feldspar megacrysts

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

PHOTOS

Graded bedding in garnet-sillimanite bearing greywacke. Thin layer of hornblende-garnet+/-dioside amphibolite exhibits boudinage. Greywacke has disruption of layering and incipient mobilizate developing in the semi-pelitic beds.

As previous photo showing prefferential shearing an isoclinal folding in the bedding plane of the most pelitic beds.

Oblique view of previous photo

Manitoba Geological Survey, 2017