Geochronology and Tectonic Implications of Diabase Intruded Into Xiangshan Group in the Southeastern Alxa Block, NW China

The southeastern Alxa Block(i.e.,the Hexi Corridor)is a tectonic junction between the North China Block(NCB)to the east,the Alxa Block to the north,and the western Qinling–North Qilian Orogenic Belt to the southwest(Fig.1).The southeastern Alxa Block had