Northern limit of Gondwana in northwestern Mexico from detrital zircon data

Abstract

UPb geochronology along a north-south transect from central Sonora to northern Sinaloa in northwestern Mexico indicates several changes in provenance sources through time and space. Lower Cambrian arenites of the Proveedora Quartzite yield a single main age peak at 1075 Ma with minor Paleoproterozoic contribution. Arenites from the Sonobari Complex of southwestern Sonora-northwestern Sinaloa, purportedly assigned to the early Paleozoic, yield main peaks at 1424, 1662, and 1736 Ma, probably derived from the Yavapai and Mazatzal provinces, which are pervasively intruded by early Mesoproterozoic granites coeval to those forming the Granite-Rhyolite Province. Lower to Upper Ordovician units deposited on shelf, slope, and abyssal environments display very similar zircon age patterns, with main peaks ca. 2700 and 1850 Ma, indicating a large drainage system arising from the Archean cratons of Laurentia such as the Wyoming or Superior Provinces, and Paleoproterozoic sources similar to the Trans-Hudsonian orogen, which are older than the Yavapai Province. The Río Fuerte quartzites from southern Sonora-northern Sinaloa contain main peaks at 534, 542, and 637 Ma whose sources may be peri-Gondwanan blocks similar to Avalonia or Carolina terranes. A minor peak at 475 Ma suggests input from igneous suites reported from the Acatlán Complex in southern Mexico. UPb geochronology permit inference of a late Paleozoic collisional orogen in northwestern Mexico that was originated by the collision of Gondwanan blocks against southern Laurentia and outline the boundary between terranes related to continental blocks in the Pangaea supercontinent.