Cross Lake Project (1983-86)
Geologist P.G. Lenton
Year 83
STATION 5041
EASTING 570986
NORTHING 6041657
ZONE 14
DATUM NAD83
Date of mapping 06/23/1983
STRUCTURAL DATA
Structure type | Strike | Dip | Separation |
---|---|---|---|
schistosity | 220 | 0 |
Rock Number | Type | Width (m) | Strike | Dip |
---|---|---|---|---|
3 | diabase | 1.55 | 142 | 80 |
Type | Plunge | Azimuth |
---|---|---|
rodding | 60 | 115 |
PETROLOGIC DATA
Rock Number: 1
-grey tonalite/granodiorite
- appears to be the older unit but not as severly deformed or sheared as at other locals. Weathers pale greyish-white with a well defined lensoid BO segregation visible on fresh surface.
-weakly megacrystic-felspars 2 to 3 mm in an average 1 to 1.5 mm grain size
Type | Mineral | Min. Size | Max. Size | Abundance (%) | Unit |
---|---|---|---|---|---|
phenocryst | plagioclase | 2.0 | 3.0 | mm | |
mafic mineral | biotite | 0.0 | 0.0 | ||
groundmass grainsize | 0.0 | 1.5 | mm |
Rock Number: 2
-first convincing pillowed volcanic seen in Clearwater Bay.
-black weathering massive amphibolite with anastomosing veinlets of hornblende + plagioclase +/- epidote that look like selvages
Mineral | Abundance (%) |
---|
hornblende |
plagioclase |
epidote |
Rock Number: 3
-155 cm maximum width with 10 cm chill margin
-sample A 40 cm into dike
-sample B lower contact chill margin
-weathers dark green with some remnant plagioclase lathesd; diabasic texture
PHOTOS
Fine grained greenish black diabase dike. The unfoliated nature, clean sharp contacts and strike of 142° suggests this may be a Mackenzie dike rather than an offshoot of the Molson dikes.
Flattened and stretched amphibolite raft that still has convincing characteristics of pillowed basalt.
Manitoba Geological Survey, 2017