Cross Lake Project (1983-86)

Geologist P.G. Lenton Year 83 STATION 5154
EASTING 573378 NORTHING 6049103 ZONE 14 DATUM NAD83
Date of mapping 07/20/1983

STRUCTURAL DATA

PETROLOGIC DATA

Rock Number: 1

Rock Type: pegmatite
Descriptors:
large dike
Field Description:

-ANDERSON DIKE A-8
-3 photos of dike cross cutting quartz - calcite - tourmaline - chlorite - garnet vein system
-This would seem to indicate tourmaline vein alteration preceded the rare element enriched dikes or alternately that fluids from main dike invaded the older quartz-carbonate vein system.
-dike has strong preferred fabric of tourmaline and spodumene with less preferred orientation of microcline
*Trend 043 degrees
-Dike is actually just a big podiform body at its maximum thickness at the exposed area
-general trend of body around 297 degrees
-coarse granitic with rare beryl, very abundant tourmaline and spodumene
- tourmaline dominantly fine acicular - no large masses like at 5153
- garnet along borders pale orange - probable spessartine
-apatite aquamarine

PHOTOS

Anderson dike A-8
Spodumene bearing dike cutting highly deformed pillow basalt and mafic sediments.
Quartz carbonate veins with chlorite, tourmaline and garnet appear to preceed the spodumene dike but may have been invaded and altered by the younger dike.
Note the strong preferred orientation of the spodumene and tourmaline crystals.

Closeup of quartz carbonate vein. Note the alteration veins crossing into the pegmatite.

Manitoba Geological Survey, 2017