Age and Provenance of the Daur Series Sedimentary Rocks (Riphean), Argun Continental Massif: Results of U–Th–Pb and Lu–Hf Isotope Studies of Detrital Zircons

Abstract

The first results of U–Th–Pb and Lu–Hf isotope studies of detrital zircons from sedimentary rocks of the Daur Series (Argun continental massif of the Central Asian Fold Belt) are presented. It is established that the youngest detrital zircons from sandstones of the Urulungui and Dyrbylkei formations of the Daur Series have the ages of 899 and 771 Ma, respectively. These data determine the maximum depositional age of the Daur Series and agree with the current ideas about the Late Riphean age of this series. The majority of Late Riphean detrital zircons from sedimentary rocks of the Daur Series are characterized by Early Precambrian Lu–Hf model ages. In addition, the Archean and Early Proterozoic detrital zircons are present in the studied rocks. This suggests either the presence of ancient (Early Precambrian) recycled material in the sedimentary rocks of the Daur Series or the fact that the studied part of the Argun massif is an “exotic block,” whose origin requires additional research.