U-Pb detrital zircon geochronology of the Turee Creek Group, Hamersley Basin, Western Australia: Timing and correlation of the Paleoproterozoic glaciations
Résumé
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 di
ff
erent 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 identi
fi
ed in drill core
samples from the Hardey Syncline area. The youngest detrital zircons have an age of ca. 2.45 Ga in these dia-
mictites supporting the hypothesis that these horizons represent a di
ff
erent 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 Africa basins, and reconstructing the sequence of redox and climate changes at-
tending the early Paleoproterozoic.