place 1.85 billion years ago. Based on the metamorphic ages in the Trans North China Orogen, the assembly and the formation process of the North China Craton is determined. Zhao proposed that the North China Craton was formed from 4 blocks, the Yinshan Block, the Ordos Block, the Longgang Block and the Langrim Block. The Yinshan and Ordos Blocks collided and formed the Western Block, creating the Khondalite Belt 1.95 billion years ago. For the Eastern Block, there was a rifting event in the Jiao-Liao-Ji Belt, which separated the Longgang Block and the Langrim Block with an ocean before the block was formed 2.1 to 1.9 billion years ago. A rifting system is proposed because of how the rocks were metamorphosed in the belt and symmetrical rocks have been found on both side of the Belt. Around 1.9 billion years ago, the rift system at the Jiao-Liao-Ji Belt switched to a subductional and collisional system. The Longgang Block and the Langrim Block then combined, forming the Eastern Block. 1.85 billion years ago, the Trans North China Orogen was formed by the collision of the Eastern and Western Blocks in an eastward subduction system, with probably an ocean between the 2 blocks subducted. Zhao also proposed model about the interaction of the North China Craton with the Columbia Supercontinent. He suggested that the craton's formation event 1.85 billion years ago was part of the formation process of the Columbia Supercontinent. The craton also recorded outward accretion event of the Columbia Supercontinent after it was formed. The Xiong'er Volcanic Belt located in the Southern Margin of the craton recorded the accretion event of the Supercontinent in terms of a subduction zone. The North China Craton broke away from the Supercontinent 1.6 to 1.2 billion years ago via a rift system called Zhaertai Bayan Obo rift zone where mafic sills found is an evident of such event. Kusky and Zhao's arguments against the other models Kusky and Zhao proposed arguments against each other's model. Kusky argued that the 1.8 billion years ago metamorphic events found by Zhao to prove the amalgamation event is just the overprint of the collision event with the Columbia Supercontinent 1.85 billion years ago. The collision event with the Columbia Supercontinent also replaced lithosphere with new mantle, which would affect the dating. Another argument is that the metamorphic rocks found 1.8 billion years ago is not confined to the