Central Orogenic Belt (or Trans-North China Orogenic Belt). They are also found in the Western Block, indicating that the metamorphic events was a craton-wide event. Zhao, on the opposite, argued that based on the lithological evidences, for example, the Eastern and Western Blocks must have been formed in settings different from the central part 2.6 to 2.5 billion years ago. Therefore, they would have been separated at that time. The pluton upwelling may explain the metamorphic event 2.5 billion years ago. Zhao also argued that Kusky has not provided sufficient isotopic evidence regarding the metamorphic data. In contrast with Kusky's argument that deformation events should follow tight with each other rather than staying still for 700 million years, Zhao argued that there are a lot of orogens in the world that have stayed still for a long period of time without any deformation events. Other Models (Zhai's 7 Blocks Model, Faure and Trap 3 Blocks Model, Santosh Double Subduction Model) Apart from the models which Kusky and Zhao proposed, there are some other models available to explain the tectonic evolution of the North China Craton. One of the models is proposed by Zhai. He agreed with Kusky on the time frame of deformational events occurred in the North China Craton. He also proposed that the continent grew from around 2.9 to 2.7 billion years ago, amalgamating 2.5 billion years ago and deforming around 2.0 to 1.8 billion years ago due to its interactions with the Columbia Supercontinent. The mechanism behind these tectonic events is rift and subduction system, which is similar to the two models proposed by Kusky and Zhao. There is a major difference of Zhai's theory with the above-mentioned models: he proposed that the North China Craton, instead of simply amalgamated and formed from the Eastern and Western Blocks, was amalgamated from a total of 7 ancient blocks. Zhai found that the high-grade metamorphic rocks, a good indicator of amalgamation events, has been observed all over the craton, not just restricted to the Trans-North China Orogen or the Central Orogenic Belt. He then proposed that there must have been more blocks that participated in the amalgamation process in order to explain the presence of belts of high-grade metamorphic rocks, which must have been formed in a strong deformation event that created a high pressure and high temperature environment. Faure and Trap proposed another model based on the dating