Origin of terranes in the eastern Central Asian Orogenic Belt, NE China: U–Pb ages of detrital zircons from Ordovician–Devonian sandstones, North Da Xing'an Mts.

Abstract

Our new data provide evidence for the depositional age and tectonic setting of Ordovician–Devonian sandstones in the northern Da Xing'an Mountains, the eastern segment of the Central Asian Orogenic Belt (CAOB). The depositional age of the Duobaoshan Formation is younger than Middle Ordovician (462 ± 5 Ma), that of the Woduhe and Huolongmen formations is younger than Late Silurian with the youngest detrital zircon age of 417 ± 8 Ma, and 419 ± 5 Ma, respectively. The depositional age of the Niqiuhe Formation is younger than Early Silurian with the youngest detrital zircon age of 432 ± 6 Ma. All the detrital zircon ages of Ordovician–Devonian sandstones represent similar distribution characteristics in probability diagrams showing four dominant populations of ~ 500 Ma, ~ 800 Ma, ~ 1800 Ma and ~ 2500 Ma. These age groups are widely found in Devonian or pre-Devonian clastic sediments and metamorphic complexes of NE China and Mongolia. Combined with new paleomagnetic data from the Baydaric and Tuva–Mongolian composite blocks in Central Mongolia and from the Lesser Karatau block of Central Kazakhstan, and the age information from adjacent cratons and continental microplates, we suggest that the basement blocks of NE China have their origin in the Tarim craton. These basement blocks include the Erguna and Jiamusi–Khanka–Bureya blocks which rifted from the Tarim craton at ~ 800 Ma and moved close to the Siberian craton at (or earlier than) ~ 500 Ma with other microcontinents within the CAOB.