Zircon U-Pb age and geological background of rhyolite from Baiyingaolao Formation in Wunuer area, Great Xing'an Range

This paper is the result of geological survey engineering.

Objective The Baiyingaolao Formation is an important part of the Mesozoic volcanic rocks in Great Xing'an Range, Northeastern China, and the geochronology and geochemistry characteristics of the Baiyingaolao Formation can provide basic geological data for the tectonic evolution of Great Xing'an Range.

Methods In this paper, LA-ICP-MS zircon U-Pb age and geochemistry of the rhyolites in Baiyingaolao Formation from Wunuer area in Great Xing'an Range have been carried out.

Results The testing results indicate that the LA-ICP-MS zircon U-Pb crystallization age is (127.6 ±1.2Ma) Ma, which belongs to Early Cretaceous. The rhyolites belong to high-SiO₂, high-K peraluminous, calcalkaline series. The rhyolites are enriched in Rb, Ba, K, depleted in Sr and Nb, P, Ti, and LREE is enriched and HREE is relatively depleted, with moderate Eu-rich anomaly (δEu=0.49~0.87).

Conclusions Combined with regional geological characteristics, the tectonic setting of rhyolites in Baiyingaolao Formation from Wunuer area in Great Xing'an Range may be related to the subduction of Pacific plate.