U-Pb detrital zircon geochronology of the Turee Creek Group, Hamersley Basin, Western Australia: Timing and correlation of the Paleoproterozoic glaciations

摘要

The early Paleoproterozoic Turee Creek Group (TCG), Hamersley Basin, Western Australia, records a continuous siliciclastic-dominated sedimentary sequence across the Great Oxidation Event (GOE) and contains at least two glacial horizons showing many similarities with other Paleoproterozoic glaciogenic deposits from North America (Huronian Supergroup) and South Africa (Transvaal Supergroup). The correlation between these glacial events is uncertain, however, because of a lack of geochronological constraints, contradictory stratigraphic correlations among different cratons, and the occurrence of numerous sedimentary discontinuities in the Transvaal and Huronian successions. In this study, we performed in situ U-Pb dating of detrital zircons from drill core and surface samples of the TCG, the underlying Boolgeeda Iron Formation of the Hamersley Group, and the overlying Beasley River Quartzite of the Lower Wyloo Group. Over 1500 zircons analyzed by Laser Ablation coupled to ICP-MS yielded major age peaks spanning the Archean Eon at ca. 2.45 Ga, 2.54 Ga, 2.68 Ga and minor ones at 2.81 Ga, 2.96 Ga and 3.14 Ga. A younger age of 2340 +/- 22 Ma obtained at the base of the main glacial deposit of the Meteorite Bore Member, represents a maximum age for this glacial event. A meter-scale level of diamictite has previously been described in the Boolgeeda Formation at the Boundary Ridge Locality (located about 50 km to the east of the Meteorite Bore Member succession) and a similar horizon was newly identified in drill core samples from the Hardey Syncline area. The youngest detrital zircons have an age of ca. 2.45 Ga in these diamictites supporting the hypothesis that these horizons represent a different and older glacial event than the Meteorite Bore Member. Considering that the TCG and underlying Boolgeeda Iron Formation are in sedimentary continuity, these results allow establishing a correlation with the other glaciogenic deposits recorded in the North America and southern Afr