Cross Lake Project (1983-86)

Geologist P.G. Lenton Year 83 STATION 5160
EASTING 573414 NORTHING 6049865 ZONE 14 DATUM NAD83
Date of mapping 07/24/1983

STRUCTURAL DATA

PETROLOGIC DATA

Rock Number: 1

Rock Type: pegmatitc granite
Field Description:

-eastern most end of pegmatite granite
-contrast on north with greywacke
-there are several dikes (folded) the same as previous station
K-feldspar, plagioclase, tourmaline, biotite, garnet, apatite (green to bluish green) with no muscovite
-transition into pegmatitic granite is accompanied by appearance of coarse muscovite and disappearance of apatite
-this disappearance of apatite may suggest folded dikes have a different and possibly older source
-pegmatitic granite is probably properly named as it is significantly different in texture from pegmatites
-there are large areas of coarse to very coarse biotite, muscovite, albite, quartz, tourmaline +/- microcline granite
-in addition there are regular style pegmatitic pods up to several metres in size with giant blocky microcline, blocky albite up to 50 cm, massive quartz and 5 to 30 cm biotite, muscovite and large columnar tourmaline.
-the textural disparity of much of the dike suggests it really is pegmatitic granite

Manitoba Geological Survey, 2017