那丹哈达地体与东亚大陆边缘中生代构造的关系

THE NADANHADA TERRANE IN RELATION TO MESOZOIC TECTONICS ON CONTINENTAL MARGINS OF EAST ASIA

中国黑龙江省境内的那丹哈达地体属于侏罗纪裂解的地体,主要由石炭、二叠纪灰岩和绿片岩、三叠纪层状燧石以及中侏罗世的硅质页岩组成。它们都被包裹在较年轻(晚侏罗世-白垩纪的)碎屑岩中。该地体的地层古生物、岩石以及构造特征完全与日本列岛的美浓地体相同。在日本海形成之前,两个地体曾与西锡霍特阿林地体一起构成一个统一的超地体。与那丹哈达地体和美浓地体十分类似的构造地层地体在琉球岛弧,菲律宾以及婆罗洲也能找到。三叠纪中国大陆拚贴作用完成之后,所有这些地体在晚侏罗世和早白垩世期间沿着亚洲大陆东缘组成了一个增生杂岩带。

The Nadanhada terrane, a Jurassic disrupted terrane in Heilongjiang Province of China, is principally composed of Permo-Carboniferous limestone and greenstone, Triassic bedded chert and Middle Jurassic siliceous shale, all enclosed within younger (presumably Late Jurassic-Early Cretaceous) elastics. Paleontological and petrological characteristics and structural features of these formations are entirely identical to those of the Mino terrane of the Japanese Islands. In both terranes there exist the same Triassic radiolarians as well as chaotic mélanges with similar compositions. In the Sikhote-Alin region, geologic formations lithostratigraphically and biostratigraphically equivalent to those of the Nadanhada area are ubiquitously distributed. Fossils contained in olistostromic blocks in the Ryukyu Arc, Philippines and Borneo are also quite similar to those in the Japanese Islands. Therofore, it is inferred that these Mesozoic terranes in the western Pacific region were originally a single superterrane and disrupted before the Late Jurasic to form many small ones, which constituted a belt of accretionary complexes during Late .Jurassic and/or Early Cretaceous time along the eastern continental margin of Asia after completion of the Triassic collage of the Chinese continent. Just after, or along with, this accretionary process, horizontal compressoshear displacement took place in Middle to Late Cretaceous. Finally, with The opening of the Sea of Japan in Neogone time, the Mino terrane was divorced from the Nadanhada and Sikhote Alin terranes and arrived at its current position.In summary, the Nadanhada terrane is closely related to the Mesozoic tectonics of the Circum-Pacific domain.