Late Cretaceous-Tertiary tectonic inversion of northeastern Asian continental margin: Insight from the low temperature thermochronology in NE China

Abstract

We studied a less understood area of basins and basement horsts to the east of the Songliao basin, NE China. An integrated evaluation of the thermal history of both the basement highs and the basin remnants was performed using low-T thermochronology and burial/thermal modelling based on vitrinite reflectance data. We present new apatite and zircon (U-Th)/He and apatite fission track results from an area of ca. 100,000 km2 covering largely the eastern part of the satellite basin system in order to elucidate the post Jurassic thermal history of the basement highs bordering the sub-basins. The low-T thermochronometers show mostly Late Cretaceous - early Paleogene apparent ages, younger than the Early Cretaceous sedimentary record in the related satellite basins. These age constraints are in harmony with the thermal modelling of vitrinite reflectance data from the basins, which indicates that the maximum burial depth occurred in mid-Cretaceous. The following major basin inversion leads to erosion from ca. 110 ca. 40 Ma. The modelling indicated that in the Jiamusi Uplift the central part experienced deeper erosion than marginal areas. Combining the above modelling results, we suggest a single united down-warped basin that formed in the Early Cretaceous, and covered the currently elevated western Zhangguangcai Range and eastern Mishan Uplift at the time of its maximum extent. The Late Cretaceous - Paleogene exhumation of the Jiamusi Uplift, gradually destroyed the formerly continuous, 1.6 to 4.8 km thick sedimentary cover and only basin remnants have been preserved.