Cross Lake Project (1983-86)


Geologist    P.G. Lenton     Year    86     STATION    6131
EASTING   557849     NORTHING   6024562     ZONE   14     DATUM   NAD83
Date of mapping    06/14/1986

STRUCTURAL DATA

Planar Structures:
Structure type Strike Dip Separation
schistosity 35 67

PETROLOGIC DATA

Rock Number: 1

Rock Type: gabbro
Descriptors:
massive
hornblende bearing
leucocratic

Field Description:

-leucogabbro
-sample taken
-most of island (around 80%) dark grey speckled with black mafic intrusive rock either leucogabbro/diorite
-plag. alters to GR-epidote indicating Ca-plag. comp inclusions of UM-hornblendite and fine grained black diorite (see rock #2)
-gabbro agmatized by buff peg-granite (see rock #3)
-variety of inclusion (probably cognate in gabbro of both fine and coarse grained mafic rock)

Rock Number: 2

Rock Type: diorite
Descriptors:
massive
mesocratic

Field Description:

-sample taken
-fine grained greenish black weakly-non-foliated homogeneous equigranular field rel. uncertain but appears to be included in gabbro as a single inclusion 1x2 m

Rock Number: 3

Rock Type: granite
Descriptors:
pegmatitic
leucocratic

Field Description:

-2 samples taken
-leucogranite modal white and biege quartz-rich granite
-grain size: 3 mm equigranular-->GRDR pegmatite
-contains minor MG BO only mafic


Manitoba Geological Survey, 2017