Cross Lake Project (1983-86)


Geologist    P.G. Lenton     Year    83     STATION    5129
EASTING   575887     NORTHING   6041837     ZONE   14     DATUM   NAD83
Date of mapping    07/10/1983

STRUCTURAL DATA

Dikes and Sills:
Rock Number Type Width (m) Strike Dip
1 Molson dike 0.00 236 77

PETROLOGIC DATA

Rock Number: 1

Rock Type: gabbro

Field Description:

Footwall section
-1a lower chill
-1b 6.5 m above lower contact - 2 pyroxene gabbro
-1c coarse leucocratic gabbro with cumulate layering 14 m. above footwall
-excellent cumulate features including scours and cross bedding
PHOTO 1 - contact between cumulous and leucocratic gabbro layers
PHOTO 2 & 3 - truncation of layers in cross bedded sequence
PHOTO 4 - truncation of layering in scour
PHOTO 5 - high angle truncation of layering by leucocratic gabbro
PHOTO 6 - reprosentative photo of leucocratic gabbro
PHOTO 7 - cross bed truncation
PHOTO 8 - lamination in magma tube
PHOTO 9 & 10 - over view of outcrop showing magnitude of cross bedding

PHOTOS


Contact between orthocumulate layer and leuco-gabbro layer.


Layer truncation in crossbedded sequence.


Larger view of previos layer trauncation.


Truncation of layering in a scour. Note the autolith below the scale card.


High angle truncation of layering by leuco gabbro.


Representativee photo of the leuco gabbro (anorthositic gabbro).


Crossbed truncation.


Lamination in a magma tube piercing thick bedded orthocumulate.


Overview of outcrop showing the scale of the crossbedding.


Manitoba Geological Survey, 2017