Abstract
A major intracontinental extensional province, more than twice the size of the Cenozoic Basin and Range Province of North America, developed in east Asia during late Mesozoic time. Like the Basin and Range, the east Asian province features numerous extensional basins that developed in both low-strain and high-strain settings within heterogeneous crust that had experienced prior shortening. The low-strain basins comprise isolated or linked half-grabens that are characterized by fluvial-lacustrine facies assemblages and internal drainage. In northeastern China, normal faults that bound numerous Early Cretaceous half-graben basins sole into Jurassic thrust faults at depth, demonstrating that the geometry of low-strain extension was strongly influenced by the prerift basement structure. Across Mongolia, from at least 98° longitude eastward, lacustrine-sourced petroliferous basin areas formed from Late Jurassic–Early Cretaceous syn-rift depocenters that locally coalesced due to progressive fault linkage. An Upper Cretaceous postrift succession was deposited following an episode of mid-Cretaceous transpression that inverted many of these basins. High-strain basins associated with Early Cretaceous metamorphic core complexes constitute supradetachment basin systems typically filled with thin (<1.5km) successions of dominantly coarse-grained alluvial strata derived from the footwalls of successive detachment splays.