关键词: 华北地块北缘, 中新元古代, 构造演化, 大陆边缘, 超大陆

Abstract:

The formation of continental rift basin in the northern margin of the North China block is caused by the breakup of the
Columbia supercontinent according to previous study and analysis of our eight measured sections. Due to the continued crustal
extension and creation of oceanic crust, the northern North China block involved into a passive continental margin, which then
turned into an active margin around 1400 Ma after the deposition of the Tieling Formation. The low-angle subduction of the
oceanic crust beneath the North China block resulted in a compression environment in the back-arc area (Qinyu Uplift), thus
leading to the uplift and erosion of the Tieling Formation. Presumably, high-angle subduction of the oceanic crust followed, and
caused intense rifting and deposition of the Xiamaling Formation accompanied by the intrusion of diabase dykes. The uplift of
the Xiamaling Formation (or Yuxian Uplift) was related to the collision between the North China block and the adjacent block,
accompanied by occurrence of the collision-related granites. The time of contractional event coincided with the formation age
of the Rodinia supercontinent. Neoproterozoic successions might be related to the breakup of the Rodinia supercontinent.
Quartzarenites and glauconitic sandstones of the Longshan Formation is the earliest deposition after the breakup of the Rodinia
supercontinent, recording the early transgressive processes.

Key words: northern margin of North China block, Meso-Neoproterozoic, tectonic evolution, continental margin, supercontinent