A sedimentary facies analysis of the >2.8 GA Beniah and Bell Lake formations, Slave Province, Northwest Territories

The Slave Province, located in the Northwest Territories, hosts a number of Archean shelf-type sedimentary successions (ca. 2.8–2.9 Ga) that lie adjacent to major, north-trending crustal-scale lineaments. These basins contain mineralogically mature quartz-arenites that have formed under specific climatic, hydraulic and tectonic conditions. The sedimentary rocks unconformably overlie >3.0 Ga tonalite-granodiorite basement and layered igneous complexes and are overlain by 2.6–2.7 Ga mafic and felsic volcanic rocks.; The 100 to 1000 m-thick Beniah Formation (∼150 km northeast of Yellowknife, NWT) contains four distinct lithofacies including: (1) the 2–13 m-thick conglomerate (CL), (2) the 10–120 m-thick quartz-arenite (QAL), (3) the 10–16 m-thick sandstone-siltstone (SaSL) and (4) the 5–13 m-thick siltstone-sandstone (SiSL) lithofacies.; The ubiquitous tabular geometry of the lithofacies, the multiform composite cross-strata, bimodal/bipolar paleocurrent patterns and abundance of mudstone drapes strongly support tidal influence for the Beniah Formation with evidence of lesser wave and storm activity.; Supplementary data from the Bell Lake Formation (∼45 km north of Yellowknife) revealed three distinct lithofacies: (1) the 2–10 m-thick quartz-arenite, (2) the 1–12 m-thick sandstone-siltstone and (3) the 0.5–30 m-thick iron formation lithofacies. (Abstract shortened by UMI.)...