Continent‐scale sediment dispersal for the Proterozoic Baraboo Interval quartzites in the Laurentian midcontinent

Abstract

AbstractThe well‐known Baraboo Interval quartzites in the Laurentian midcontinent are a succession of mature red siliciclastic strata, locally more than 1.5 km thick, and covering an area >300,000 km2, much if not all of which was deposited after the Mazatzal orogeny (<1.63 Ga), and before the Baraboo Orogeny (~1.47 Ga). Ca. 1,300 new LA‐ICPMS detrital zircon ages from six Baraboo Interval inliers in Wisconsin and the Sioux Quartzite in South Dakota, USA attest to significant distal provenances not previously recognized. The principal ~1.8–1.9 Ga and >2.5 Ga age peaks represent local, southern Superior province sediment source areas. Yet more than 30% of our dataset includes ages between 1.9 and 2.5 Ga which are essentially absent from the region. We interpret these non‐locally derived zircons to have been transported ~2,500 km southeast to the Columbian supercontinental margin. The subsequent accretion of the Mazatzal terrane caused a major drainage reorganization, and transport of sediment for the uppermost Baraboo interval strata was north rather than south‐directed.