Detrital zircon geochronology and grain-size analysis of a ∼2800 Ma Mesoarchean proto-cratonic cover succession, Slave Province, Canada

Detrital zircon populations of five quartzite samples of the ∼2800 Ma Central Slave Cover Group, Slave Province, have been investigated to explore regional lithostratigraphic correlation/diachroneity, maximum depositional ages, ages of underlying basement, and general provenance issues. A total of 346 grains were analyzed by sensitive high resolution ion microprobe for U–Pb ages and by digital image analysis for grain size. Ages of individual grains range from 3918 to 2808 Ma and define several important modes, notably at ∼3400 Ma, 3150 Ma, 2950 Ma, and 2826 Ma. Although the samples show significant differences, suggesting localized rather than well-mixed sediment provenances (supported by grain-size statistics), some modes are shared among the samples in a pattern that supports regional correlation. Nevertheless, the ages of the youngest detrital modes, in conjunction with independent age constraints from a parallel study, indicate either diachroneity in the cessation of quartz arenite deposition across the realm of the Central Slave Cover Group or a difference in basement domains.