Detrital zircon geochronology and grain-size analysis of a ~2800 Ma Mesoarchean protocratonic 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.