Cross Lake Project (1983-86)

Geologist P.G. Lenton Year 86 STATION 6284
EASTING 569883 NORTHING 6047645 ZONE 14 DATUM NAD83
Date of mapping 07/04/1986

STRUCTURAL DATA

Planar Structures:
Structure type | Strike | Dip | Separation
cataclastic foliation | 281 | 65 |

Linear Structures
Type | Plunge | Azimuth
rodding | 24 | 91

-complex of intrusive rocks with inclusions as a layered cataclasite sequence
PHOTOS
1,2 -rock 2 included in rock 1
3 -general view of outcrop
4 -ampb inclusion
5 -rock 4 augen leuc. GRNT
6 -rock 5 sheared aplite
7 -rock 6 sheared GRDR dikes in rock 1

PETROLOGIC DATA

Rock Number: 1

Rock Type: granodiorite
Descriptors:
cataclastic
leucocratic
Field Description:

-grey subgneissic rock with slight augen texture produced by feldspar aggregates sandwiched between BO lenses
-this appears to be the dominant rock as it includes rock 2 and rock 3 but is cut by rock 4, 5, 6
-it bears some resemblance to the grey porphy but could just as easily be a CWB TNLT-GRDR
-no trace of FL ro GR
-BO is extensivly chloritized on the shears
-QUARTZ=25%

Rock Number: 2

Rock Type: tonalite
Descriptors:
augened
biotite
Field Description:

-dark grey augen gneiss that may have been a HB TNLT
-highly flattened and sheared inclusions in rock 1 ranging from 15% to locally 65% of exposure
-essentially an aggmatite
-I can't correlate this with the fluorite complex or with CWB
-quartz appears to be low, may be 10 to 15% (?) so this may actually be an old QZDT and part of old mafic complex

Rock Number: 3

Rock Type: amphibolite
Descriptors:
massive
hornblende - biotite bearing
Field Description:

-probably derived from basalt
-occurs as inclusions in both rock 1 and 2
-highly flattened and sheared
-HB extensivly altered to BO

Rock Number: 4

Rock Type: granite
Descriptors:
augened
leucocratic
Field Description:

-may also contain a trace of GR
-orangy red quartz rich (35%) granite
-has good augen texture with red feldspar aggregate augen surrounded by quartz lenses
-dikes rangig from 30 cm to 2 m
-this could be the red augen granite associated with the fluorite complex

Minerals of Note
Mineral | Abundance (%)
muscovite
chlorite

Rock Number: 5

Rock Type: granite
Descriptors:
cataclastic
aplitic
Field Description:

-very fine grained beige layered (by cataclasis) almost glassy aplite
-may be related to augen GRNT
-some segregation of QZ stringers

Rock Number: 6

Rock Type: granodiorite
Descriptors:
augened
leucocratic
Field Description:

-white weathering GRDR or granite that intrudes as a late (?) dike swarm in the foliation plane and is extensivly sheared
-it doesn't seem to be garnetiferous, but it commonly has garnets on the contacts with all other rocks, sometimes as 1 to 2 mm red GR and sometimes as 1 to 2 cm GR-QZ aggregates

Minerals of Note
Mineral | Abundance (%)
garnet

Manitoba Geological Survey, 2017