Hearne Craton

Hearne is one of the six Archaean cratons of the Canadian Shield (the other being Slave, Rae, Wyoming, Superior, Nain) that are bound together by Palaeoproterozoic orogenic belts.

During the Neoarchaean and Palaeoproterozoic the STZ played a major role when the Western Churchill Province was first assembled and then reworked.

[3] The Manikewan Ocean, a palaeocean named by Stauffer 1984, started to open along the south-east margin of Hearne at 2.075 Ga and had reached a width of 5,000 km (3,100 mi) after a hundred million years.

Intra-oceanic arc collision resulted in the Amisk Collage and the Flin Flon – Glennie Complex around 1.92–1.88 Ga.[4] Today these Palaeoproterzoic structures in the Trans-Hudson Orogen welds the Archaean Hearne and the Superior cratons.

The final closure of the ocean around 1.83 Ga, when Hearne, Superior, and Sask cratons merged with the Flin Flon – Glennie Complex, was followed by a period of metamorphism that peaked around 1.82–1.8 Ga.[4] The Manikewan Mobile Belt now covers an area of 600,000 km2 (230,000 sq mi) but is overlain by Middle Proterozoic Athabasca sandstone.