TECTONIC SETTING OF MESOZOIC VOLCANIC ROCKS IN NORTHEAST CHINA

A detailed study on the regional tectonics,magma activity,paleomagnetism,paleontology and stable isoptope shows that the Mesozoic volcanic rocks in northeast China were formed mainly in the period of late Triassic to late Cretaceous in two different surroundings The volcanic rocks, which were formed in the period of late Triassic to middle Cretaceous(230~120 Ma),were developed in the superimposition of the Paleo-asiatic tectonic domain and the marginal-Pacific tectonic domain The volcanic rocks,formed since late Cretaceous,were developed in the Cretaceous marginal Pacific tectonic domain That is why the volcanic rocks which were formed in the period of late Triassic to early Cretaceous(230~120 Ma) became newer from south to north, while the volcanic rocks which were formed since late Cretaceous became newer from west to east.