Detrital record of mountain building: Provenance of Jurassic foreland basin to the Dabie Mountains

Abstract

[1] The Huangshi foreland basin developed on the southern margin of the Dabie Mountains as a result of tectonic loading during Triassic collisional suturing between the North China and South China cratons. Modal and detrital zircon data for Jurassic samples within the basin suggest a multicomponent source with input from both the South China Craton and Dabie Orogen. Samples are predominantly quartz arenites derived, on the basis of framework compositions, from a recycled orogen source. Detrital zircons range in age from Archean to Triassic with a dominant component in the late Paleoproterozoic between 1.9–1.7 Ga and subsidiary components at 2.6–2.2 Ga, 0.8–0.7 Ga, 0.5–0.4 Ga, and 0.33–0.2 Ga. Age data integrated with cathodoluminescence and trace element data for the zircons indicate that the Archean and Proterozoic detritus was derived from igneous and metamorphic sources that overlap with time-equivalent pulses of such activity within the South China Craton. Phanerozoic zircon ages overlap the times of the Ordovician, Carboniferous and Triassic high-pressure metamorphism in the Dabie Mountains. The provenance record, integrated with paleocurrent and regional relations, enables a paleogeographic reconstruction in which the Huangshi Basin was fed by a major axial flowing trunk river system carrying detritus from eastern and southern sources within the South China Craton and was also fed by short south flowing tributaries supplying some detritus from the evolving Dabie Orogen. The dominance of cratonic-derived detritus within the provenance record of the Huangshi Basin contrasts with that of the Hefei foreland basin that lies to the north of the Dabie Mountains, which is dominated by Neoproterozoic - Mesozoic detritus derived directly from the Dabie Mountains and lacks any significant older Paleoproterozoic or Archean components. Easterly extensions of the Dabie-Sulu collisional suture and of the resultant Huangshi Basin occur in Korea and Japan over an along strike length of some 2000 km.