The eastern extension of Paleozoic South China in NE Japan evidenced by detrital zircon

The South Kitakami belt is unique in exposing a thick, well-preserved Paleozoic shelf sequence in Japan in which Phanerozoic accretionary complexes dominate. Its origin with respect to continental blocks has been debated in regard of two options, i.e., as belonging to the margin of North China or South China. Present work on U–Pb detrital zircon dating has identified Neoproterozoic mineral grains from the Silurian and Carboniferous sandstones in the S. Kitakami belt, and proved the link between Paleozoic Japan and South China with dominant Proterozoic basements. South China likely extended further to the east from the mainland China.

南北上带（South Kitakami Belt）是日本境内唯一出露厚层且保存完好的古生代陆架序列的区域，该区域以显生宙增生杂岩（Phanerozoic accretionary complexes）为主导。关于其与大陆地块的成因归属，学界曾围绕两种假说展开争论：即该带隶属于华北（North China）或华南（South China）地块的陆缘。本研究通过U-Pb碎屑锆石定年（U–Pb detrital zircon dating）技术，从南北上带的志留纪（Silurian）和石炭纪（Carboniferous）砂岩中识别出了新元古代（Neoproterozoic）矿物颗粒，并证实了古生代日本与以元古代基底为主的华南地块之间的成因联系。华南地块的分布范围可能曾向东延伸至中国大陆以东区域。