Spatio-temporal distribution and geodynamic evolution of Cenozoic volcanism in northeast China: insights from a new geochronological compilation

Abstract

ABSTRACT High-precision ages of Cenozoic volcanic rocks in northeast China are widely reported recently. However, the systematic analysis of spatio-temporal distribution of Cenozoic volcanism, which is important for reconstructing and constraining regional tectonic evolution, is still limited. Here, we collected published geochronological data from more than 400 Cenozoic volcanic samples in northeast China. Combined with field observations of volcanic rock samples and three valid 40Ar-39Ar geochronological data obtained in this study, we compile geochronological data in northeast China and explore a new spatio-temporal distribution pattern for the Cenozoic volcanism in order to constrain geodynamic models for northeast China. Our results show that the Cenozoic volcanism in northeast China has a horseshoe-shaped distribution, and the volcanism almost existed from Paleocene to Quaternary, which can be roughly divided into six volcanic belts. Our results suggest that the volcanism in this region is centred on around the Songliao Basin, then migrates eastward, and eventually has end up with a series of intense activity around the Songliao Basin. This may be related to the upwelling of the asthenosphere caused by the subduction of the Pacific plate and the opening of the Japan Sea. Our study also reveals that Chuandishan basalt in Dunhua area formed by Early Oligocene volcanic activity, which differs from the Pliocene or Miocene stratigraphic ages assumed before.