Cross Lake Project (1983-86)

Geologist P.G. Lenton Year 83 STATION 5099
EASTING 573555 NORTHING 6040306 ZONE 14 DATUM NAD83
Date of mapping 07/07/1983

STRUCTURAL DATA

Planar Structures:
Structure type | Strike | Dip | Separation
gneissosity | 72 | 79 |
fault | 298 | 77 |

Fault is a 20 cm brecciated mylonite

PETROLOGIC DATA

Rock Number: 1

Rock Type: two component schlieric gneiss - intimate mixture of 2 major units
Descriptors:
cataclastic
Field Description:

-Base rock is augen-granodiorite, highly schlieric
-early pegmatite injection is near totally homogenized by shearing
-schistosity is highly erratic, but gneissosity is planar
-biotite shows moderate segregation

Minerals of Note
Mineral | Abundance (%)
hornblende

Rock Number: 2

Rock Type: amphibolite
Descriptors:
layered
hornblende - diopside bearing
Field Description:

-highly varied inclusions of obvious volcanic source appear to be dominantly flow derived with a minor source from volcanic sediments
-highly brecciated and deformed
-much of the schlieric matierial is hornblendic and probably derived from the amphibolites

PHOTOS

General texture of the augen grandiorite showing the intense fabric.

Mylonite cutting the old granodiorite with brecciated and rotated fragments in the ultramylonite.

Layered amphibolite reduced to agmatite then schollen screens in the old augen grandiorite

Manitoba Geological Survey, 2017