Cross Lake Project (1983-86)

Geologist P.G. Lenton Year 83 STATION 5076
EASTING 571673 NORTHING 6039025 ZONE 14 DATUM NAD83
Date of mapping 06/27/1983

STRUCTURAL DATA

Planar Structures:
Structure type | Strike | Dip | Separation
schistosity | 231 | 81 |

PETROLOGIC DATA

Rock Number: 1

Rock Type: tonalite
Descriptors:
schlieric or schlieren present
leucocratic
anastomosing vein network
aplitic vein webwork
pegmatite lit
aplite veins/dikes present
Field Description:

-Anastomosing vein network of augen tonalite as previous station
-Heavily intruded by old sheared pegmatite/aplite/fine-grained granite vein networks.
-produces network with local developement of more extensive pods

Rock Number: 2

Rock Type: amphibolite
Descriptors:
massive
gabbroic
occurs as a raft
salt and pepper texture
Field Description:

-salt and pepper gabbroic rock comprising fine grained plagioclase surronding coarser 2-3 mm equant hornblende
-could possibly be volcanic derived but seems a little too massive and featureless - I would prefer to call it and early gabbro intrusive - probably intruded the volcanics
-sample B is odd - looks like a psammite but has little or no quartz - all hornblende-biotite-plagioclase -probably a fine diorite or leuco-gabbro
-Sample C- finer more mafic gabbro

Textural Features
Type | Mineral | Min. Size | Max. Size | Abundance (%) | Unit
mafic mineral | hornblende | 2.0 | 3.0 | 60.0 | mm
groundmass grainsize | plagioclase | 0.0 | 1.0 | 40.0 |

Manitoba Geological Survey, 2017