Cross Lake Project (1983-86)

Geologist P.G. Lenton Year 86 STATION 6380
EASTING 565227 NORTHING 6048765 ZONE 14 DATUM NAD83
Date of mapping 07/17/1986

STRUCTURAL DATA

Planar Structures:
Structure type | Strike | Dip | Separation
schistosity | 270 | 61 |

PETROLOGIC DATA

Rock Number: 1

Rock Type: granodiorite
Descriptors:
megacrystic
biotite
Field Description:

-excellent exposure of unit 90
-mottled pink-grey -white, med. grained leuco-GRDR with seriate phenocrysts from 4 mm to 8 cm and represent 15% of rock
-mega's are rectangular-->oval, augen and comprise microcline with concentric shells of plag. and BO inclusions with an overgrowth of creamy yellow plag. on the surface
-plag. overgrowth corresponds to the margins even when rolled suggesting the plag. growth was syntectonic
-presents a problem in interpretation suggesting 2 possibilities: (1) late magmatic stage occupied in a directed stress field with plag. overgrowths
-a late magmatitic feature or
(2) plag. is post-magmatic metasomatic origin
-I tend to favor the 1 st interpretation as the microclines show a preferred orientation in the fabric without excessive crushing and fracturing of the crystals
-foliation is invaded by numerous foliated pegmatites

Manitoba Geological Survey, 2017