Detrital zircon U-Pb and 40Ar/39Ar hornblende ages from the Aileu Complex, Timor-Leste: Provenance and metamorphic cooling history

Abstract

Geochronological data from the Aileu Complex provide new constraints on the development of the Banda Arc-continent collision. Detrital zircons of the Aileu Complex have major U-Pb age modes at 270-440 Ma, 860-1240 Ma and 1460-1870 Ma, most compatible with a sediment source located in SE Asia as part of the now fragmented Sula Spur. 40Ar/39Ar cooling ages of hornblende demonstrate an extended cooling history across the complex, with the eastern parts cooling through hornblende closure temperature by 10 Ma and central parts by 6 Ma, consistent with a variable exhumation history. The onset of cooling by 10 Ma implies that metamorphism was probably coeval with initiation of the Banda Arc. We pro..