Geological characteristics and age of the Luoguhe mudstone in the western section of Mohe basin

We identify a new set of rock assemblage mainly composed of black mudstone interbedded with siltstone, feldspar sandstone and tuff. The rocks are widely mylonitized with isoclinal folds, A lineation, S-C fabric, augen structure and so on.It is named as Luoguhe mudstone.The dating result of zircon LA-ICP-MS U-Pb in tuff interlayer is 176.3±1.1 Ma, indicating that the Luoguhe mudstone was formed in the Early-Middle Jurassic, it thrusted overthrust in Upper Jurassic Mohe Formation.The thrust direction was from NW to SE.The Luoguhe mudstone could be compared with the Lower-Middle Jurassic strata in the Upper Amur Basin and it probably came from the Upper Amur Basin.