Sanborn-Barrie et al (2001), describe three hundred million years of tectonic history in the Red Lake greenstone belt. The Red Lake belt records a long history of episodic magmatism, sedimentation and tectonothermal activity along the south margin of the 3 Ga North Caribou terrane. According to Sandborn-Barrie et al, autochtonous assemblages appear to reflect initial (2.99 - 2.96 Ga) plume magmatism, 2.94 to 2.91 Ga arc magmatism, 2.90 to 2.89 Ga sedimentation, and protracted Neoarchean continental arc and intra-arc rift-related magmatism (2.75 - 2.73 Ga). They postulate a ca. 2.85 Ga oceanic assemblage containing MORB-like basalt may have been accreted and caused early uplift and erosion prior to Neoarchean magmatism. This was followed by collisional orogenesis at ca. 2.72 Ga, the Uchian phase of the Kenoran Orogeny, which was accompanied by extensive hydrothermal alteration and gold mineralization.

Sanborn-Barrie et al indicate that the Red Lake greenstone belt comprises six distinct supracrustal assemblages of which three are important in the vicinity of the Cochenour-Campbell-Red Lake gold mines: the Balmer, Bruce Channel and Huston Assemblages. The following descriptions have been extracted from Sanborn-Barrie et al:

The Balmer Assemblage (2.99-2.96 Ga) is dominated by submarine tholeiitic basalt, komatiite and komatiitic basalt with minor felsic volcanic rocks, iron formation, and fine grained clastic rocks. This lithological association suggests deposition of the earliest recognised supracrustal rocks in sediment-starved, marine basinal setting. Basaltic flows are typically aphyric or variolitic. Ultra-mafic flows include pillowed komatiitic basalt (<18% MgO) and spinifex-textured komatiite. Basalt flows that dominate the Balmer assemblage are tholeiitic and distinguished from other basaltic sequences in the belt by their relatively high Ti contents (<2 weight %). These rocks encompass a narrow range of primitive-mantle-normalized trace-element contents from light rare-earth-element (LREE-) and large-ion lithophile-element (LILE)-depleted basalt, to more abundant, flat to slightly LREE- and LILE-enriched basalt with negative Nb anomalies. They show negative correlation between Mg content and degree of LREE enrichment.

The Bruce Channel Assemblage (2.89 Ga) appears to disconformably overlie the Balmer assemblage in eastern Red Lake (Sanborn-Barrie et al, 2001) and comprises 2894 Ma intermediate volcaniclastic fragmental rocks, locally overlain by a fining-upward sequence of chert-pebble conglomerate, cross bedded wacke, siltstone, and quartz-magnetite iron-formation. The volcanic sequence is relatively thin (<500m) and represents explosive volcanism followed by subsidence and deposition of clastic sediments and younger chemical sediments in a marine setting. Calc-alkalic volcanic rocks are dacitic to rhyodacitic and are characterised by LREE- and LILE-enriched trace-element profiles, with negative Nb anomalies.

The Huston Assemblage is a regionally extensive unit of polymictic conglomerate that marks an angular unconformity between Mesoarchean and Neoarchean strata. Along the unconformity, the character of the Huston sedimentary assemblage (<2.89 >2.74 Ga) varies from a thin veneer of clastic detritus to a thick succession of well bedded argillite and turbiditic wacke. This suggests an erosional surface of considerable relief on which deposition of sedimentary detritus under locally marine conditions took place prior to Neoarchean volcanism.