Cross Lake Project (1983-86)


Geologist    P.G. Lenton     Year    84     STATION    5460
EASTING   574512     NORTHING   6060515     ZONE   14     DATUM   NAD83
Date of mapping    06/24/1984

STRUCTURAL DATA

Planar Structures:
Structure type Strike Dip Separation
schistosity 175 89

Linear Structures
Type Plunge Azimuth
clast elongation 0 0

-F2 is a passive crenulation
-maximum stretching along F1, F2 intersection

PETROLOGIC DATA

Rock Number: 1

Rock Type: conglomerate
Descriptors:
polymictic

Field Description:

-highly stretched and crenulated, massive unsorted ungraded
-clast dominantly sedimentary with siltstone and feldspathic greywacke the most common type
-contains 3 to 5% white tonalite cobbles
-less than 1% of clasts are mafic
-these units do not appear in the Beryl Island section
-there may be thin sands horizons

Minerals of Note
Mineral Abundance (%)
garnet

Rock Number: 2

Rock Type: pegmatite
Descriptors:
granitic

Field Description:

-Microcline Oligoclase pegmatite with no definable zonation
-biotite is the principle phyllosilicate
-muscovite appears to be secondary on shears
-tourmaline is abundant occurring as clusters of large shattered crystals of up to 10x25 cm
-there is no detectable beryl
-intrusion is generally parallel to F1 but is sheared and folded about the F2 axial planar schistosity
-this seems to correspond to the most north easterly occurance of Middle Group

Minerals of Note
Mineral Abundance (%)
garnet
tourmaline
biotite


Manitoba Geological Survey, 2017