Cross Lake Project (1983-86)
Geologist P.G. Lenton
Year 83
STATION 5046
EASTING 570847
NORTHING 6040535
ZONE 14
DATUM NAD83
Date of mapping 06/23/1983
STRUCTURAL DATA
Structure type | Strike | Dip | Separation |
---|---|---|---|
gneissosity | 52 | 65 | |
fault | 61 | 82 | dextral |
fault | 303 | 87 | dextral |
-beautiful 5 cm mylonites with pseudotachylite and dextral fault drag
-major mylonite zone 5 metres wide
PETROLOGIC DATA
Rock Number: 1
-much more like 5006
-complex multi-component migmatite(gneiss) with 2 dominant phases; old gneissic tonalite (sample A) and younger grey porphyritic granodiorite (sample B) with numerous generations of pegmatitic lit, aplite and pegmatite dikes, and some minor unidentifiable granitoid phases.
sample C of 5 cm wide mylonite
Rock Number: 2
-partially digested, partly schlieric 30x100 cm rafts elongate in foliation
PHOTOS
Dextral mylonite with well developed pseudotachylite seams cutting the old leucocratic augen tonalite.
Close-up of the late shear showing quartz infill in extension zone (?).
Manitoba Geological Survey, 2017