Sedimentary basin and detrital zircon record along East Laurentia and Baltica during assembly and breakup of Rodinia

Abstract

Tectonic processes associated with supercontinent cycles result in a variety of basin types, and the isotopic dating of detrital minerals within sedimentary sequences assists palaeogeographical reconstructions. Basins located along the Laurentia–Baltica margin prior to assembly of Rodinia at 1.2–1.0 Ga are dominated by zircon detritus derived from contemporaneous magmatic arcs. Basins formed during assembly are also dominated by zircon detritus with ages similar to that of sediment accumulation, reflecting syn-collisional magmatism and rapid exhumation of the developing Grenville–Sveconorwegian orogen. Post-collision intracratonic basins lack input from syn-depositional magmatism, and are dominated by significantly older detritus derived from the mountain range as well as its foreland. Basins formed during late Neoproterozoic to Cambrian breakup of Rodinia are divisible into two types. Those within the Caledonides lie on the Grenville–Sveconorwegian foreland and incorporate Archaean and Palaeoproterozoic detritus derived from the cratonic interior and Mesoproterozoic detritus derived from the eroded remnants of the orogen. In the Appalachian orogen, such basins are dominated by Mesoproterozoic detritus with older detritus forming only a minor component, suggesting restricted input from the cratonic interior as a result of either the Grenville orogen still forming a drainage divide or the formation of rift shoulders.