The Early-middle Permian Radiolarian Cherts Of The Solonker Suture,Inner Mongolia And Its Geochemical Characteristics

The Solonker suture zone is located close to the border between China and Mongolia.It is formed by the closure of the Paleo-Asian Ocean between Siberia and North China in the Paleozoic.This belt is a key area of the Paleo-Asian Ocean and thus provides important samples for the study of tectonic evolution in the eastern part of the Central Asian Orogenic Belt in North China.But the closing time of the two plates in the Central Asian Ocean and the tectonic evolution are still controversial.Radiolarian is fond of ocean environment,marine planktonic life and single-celled animals,it is widely distributed,also has a great significance in the global contrast.Because of the lacking of the other kinds of fossils in deep sea,radiolarian fossils often regard as a key evidence of ophiolite formation and geological evolution.So far the radiolarian is only found in the Solon obo region east extension of Solonker suture zone.Based on the geochemical data of the radiolarian cherts,for the main content,trace and rare earth elements,the data can determine its sedimentary environment.Relying on the 1:50 000 regional geology and mineral resources survey project in Solonker area Inner Mongolia,the author collected radiolarian siliceous rocks of ophiolite in Solonker suture zone.In the separation and identification of fossils,separated and identified 8 genera,15 species.Their coexistent time is early-middle Permian.Meanwhile,the geochemical characteristics of cherts shows that the sedimentary environment of Solonker suture zone is between continental margin and ocean basin in the early-middle Permian.It shows that the Central Asian Ocean undergoing a complex deposition and ocean evolution stages during the early-middle Permian,has a same landscape compared with the Pacific,showing how the archipelago geographical pattern.