Cross Lake Project (1983-86)


Geologist    P.G. Lenton     Year    84     STATION    5536
EASTING   569559     NORTHING   6054339     ZONE   14     DATUM   NAD83
Date of mapping    07/05/1984

STRUCTURAL DATA

Planar Structures:
Structure type Strike Dip Separation
schistosity 78 84

Linear Structures
Type Plunge Azimuth
rodding 68 74

PETROLOGIC DATA

Rock Number: 1

Rock Type: greywacke
Descriptors:
schistose
psammitic

Field Description:

-interlayered sequence of feldspathic light grey weathering, grey adn beige on fresh surface, possibly lithic arenites, dark grey siliceous Burntwood style psammite and mafic, probably hornblende bearing
-CLCC rich psammite
-around 50 % of outcrop is intruded material

Minerals of Note
Mineral Abundance (%)
garnet

Rock Number: 2

Rock Type: granite
Descriptors:
pegmatitic
leucocratic

Field Description:

-transition from seriate to mica granite to a mix of porphyry GRNT, patched PGMT adn PGMT dikes
-the leucogranite becomes very coarse containing a grain size of 1 cm or more, and starts to acquire isolated blocky microclines and small quartz pods
-this is followed by rapid transition into biotite rich pegmatite containing numerous inclusions of greywacke
-the pegs. at this location were sampled by Anderson
-garnet is abundant in sed. but rare in pegmatite
-muscovite is still a primary phase in the coarse granite but absent in pegmatite
-although there is little physical continuity the dikes frm azimothal networks
-in general, the sequence is 3 to 4 m dikes of coarse 2 mica granite with patched pegs
-margins spreading into an irregular, deformed pegmatite stock work
-there is no trace of molyphysical in any place


Manitoba Geological Survey, 2017