Formation of the Northeast Asia Continent: Constrain from three geological events

The North China Craton (Sino-Korea craton) geographically includes North China and a part or the whole Korean Peninsula, which were characterized by the geological records of ~2.5 Ga late-Neoarchean cratonization event and ~1.9–1.8 Ga Paleoproterozoic metamorphic event. New studies provide evidence suggesting that the North China Craton also includes the Precambrian basement of the Honshu-Kyushu area in Japan (proto continent of Japan). Another important consensus is that the Indosinian (Permian-Triassic) orogenic belts connected major landmasses such as Siberia, North China, and South China, thereby forming the basic structure of the present-day East Asian continent. For Northeast Asia, following the discovery of the Permian-Triassic high-pressure metamorphic rocks in Japan, the Triassic eclogite and related magmatic rocks were also identified in the southwestern corner of the Gyeonggi Massif in the Korean Peninsula. Therefore, the relevant records of the above mentioned three geological events in three regions of North China, the Korean Peninsula, and Japan provide ample evidence for determining the formation and evolution process of the Northeast Asian continent. To be more specific, the three geological events refer to the crustal growth and stabilization event in the ~2.6–2.45 Ga, the intensive Paleoproterozoic mobile belt with high-grade metamorphic event in the ~1.9–1.8 Ga, and the Permian-Early Triassic orogenic event related to the assembly of the Pangaea supercontinent. The Permian-Early Triassic orogenic event in the Japanese Islands was acknowledged as the episodic subduction processes in the paleo West Pacific Ocean, which led to the accretion of continents, resulting in the formation of the present-day Japanese archipelago. The metamorphic rocks and related granites dated back to approximately 250–220 Ma, which have been identified in the Korean Peninsula and Japan, indicated the Korean Peninsula landmass and the proto continent of Japan to be jointed together to the ancient North China landmass through the superimposed orogenic belts, i.e., the Central Asian Orogenic Belt and/or the Qinling-Dabie Orogenic Belt. It has been widely agreed that the South China Craton and the North China Craton also joined together through the Qinling-Dabie Orogenic Belt at Triassic. At the same time, the Central Asia Orogenic Belt, as a suture zone, amalgamated the North China Craton and the Siberia Craton. Such a composite jigsaw puzzle board depicts the scene of the formation of the Northeast Asia Continent, and it was a part of the formation of the Pangaea Supercontinent.