It has no surface exposure and was identified based on geophysical signatures and drilling during mineral exploration by Cominco during the 1990s.
The Trans-Hudson Orogen was a continental collision that formed following the closure of the ancient Manikewan Ocean.
[9] Mafic to ultramafic magmatism in the Winnipegosis Komatiite Belt is contemporaneous with ongoing magmatism in the Snow Lake Arc, which implies the Winnipegosis Komatiite Belt formed along a convergent plate boundary.
[1][3][5] These overlie a thin interval of conglomerate and sandstone, which lies unconformably on Superior Craton tonalites dated to 2792 million years old.
The entire belt underwent sub–greenschist to greenschist facies metamorphism, during the Trans-Hudson Orogeny.
Location of the Winnipegosis Komatiite Belt in relation to the Circum-Superior Belt (CSB) and Trans-Hudson Orogen (THO). CSB exposures on the Ottawa and Sleeper Islands are circled due to their small size. CSB-related mafic dykes and carbonatite complexes are shown as thick red lines and dots, respectively. Boundaries of cratons and CSB shown are surface exposures except Sask craton and WKB, which are not exposed at the surface, approximate subsurface extents are shown. All other geology is not subdivided (white areas). Blue areas indicate water bodies. WKB = Winnipegosis Komatiite Belt, TNB = Thompson Nickel Belt, FRB = Fox River Belt. Blue dotted line indicates the extent of the Reindeer Zone, the juvenile core of the THO. Based on work from these references.
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Dendritic clinopyroxene textures in massive Winnipegosis Komatiite flows. Ol = olivine, cpx = clinopyroxene, gl = glass. Both 'swallowtail' and 'feathery' clinopyroxene dendrites are visible.
