~2.0 Ga regional metamorphic event in Yangtze block and its heuristic significance to the geological differences evolutionary between north and south Huangling

A set of integrated Archean-Paleoproterozoic gneisses and supracrustal rocks are exposed in Huangling area, Yangtze continental nucleus, and are named Kongling Complex. Previous research shows that north and south Huangling had the same material composition and geological evolution process in Ar-Pt1. Zircon dating studies of Archean granitic gneiss from the north and the south of Huangling respectively show that two samples (HL013-1 and HL013-2) from the north huangling contain a large amount of zircons with the development of core-rim structure, and have protolith age of ~2.8 Ga and metamorphic age of ~2.0 Ga, whereas one sample (HL005-3) from south Huangling mainly contains magmatic zircons with oscillatory zones, and has a crystallization age of ~2.9 Ga only. Combined with previous research results, the authors found that the metamorphic age of ~2.0 Ga was widely obtained in the Archean-Paleoproterozoic granitic gneiss and supracrustal rocks from north Huangling, but was not obtained in the similar structures from south Huangling. This is probably due to the fact that north Hangling had widely developed ~2.0 Ga regional metamorphism but south Huangling had not, and they were probably in different massifs or different parts of the same massif in Paleoproterozoic period. The spatial distribution characteristics of 2.1-1.6 Ga tectono-magmatic events in Yangtze block indicate that there may have existed multiple Paleoproterozoic orogenic belts, characterized by the evolution of multi-block collage in Paleoproterozoic. The extensive records of 2.1-1.6 Ga tectono-magmatic events indicate that the Yangtze block is an important part of the global Columbian supercontinent.