A regional tectonic event of Katian(Late Ordovician) age across three major blocks of China  

作　　者：CHEN Xu BERGSTRM Stig M ZHANG YuanDong WANG ZhiHao 

机构地区：[1]Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences [2]Key Laboratory of Economic Stratigraphy and Palaeogeography, Chinese Academy of Sciences [3]School of Earth Sciences, Division of Geological History, The Ohio State University, Columbus, Ohio 43210, USA

出　　处：《Chinese Science Bulletin》2013年第34期4292-4299,共8页

基　　金：supported by the project of the State Key Laboratory of Palaeobiology and Stratigraphy(Y126040124);the National Natural Science Foundation of China(41172034 and 41221001);the project of the Ministry of Science and Technology of China(2011ZX05008-001-10)

摘　　要：The present paper deals with a tectonic event of Late Ordovician age affecting three blocks of China,i.e.South China,North China and Tarim.In the North China and the Tarim platforms,as well as their marginal belts,there was a regional uplift during the early Katian Stage of the Ordovician.The uplift was indicated by the unconformities between the Ordovician successions and overlying late Paleozoic strata.New biostratigraphic studies of conodonts and graptolites from many sections at Longxian and Yaoxian,North China shows that the youngest Ordovician strata are of the early Katian age corresponding to graptolite Diplacanthograptus spiniferus Biozone.The same level has been recognized to represent the uppermost Ordovician in the platform area of Tarim,whereas in the marginal belt the top boundary of the Ordovician is slightly younger,corresponding to the graptolite Dicellograptus complanatus Biozone.Thus,the regional uplift in North China and Tarim is shown by the disconformity between the early Katian strata and Late Paleozoic strata,the onset coinciding with that of the Kwangsian Orogeny in South China.The designation Kwangsian Orogeny later fell into disuse and was replaced by the term Caledonian Orogeny.However,in terms of geographic location,tectonic nature,and the timing of activity,the Caledonian Orogeny differs significantly from the orogenic event in South China,and the continued use of this term in South China is inappropriate and misleading.The present paper deals with a tectonic event of Late Ordovician age affecting three blocks of China, i.e. South China, North China and Tarim. In the North China and the Tarim platforms, as well as their marginal belts, there was a regional uplift during the early Katian Stage of the Ordovician. The uplift was indicated by the unconformities between the Ordovician successions and overlying late Paleozoic strata. New biostratigraphic studies of conodonts and graptolites from many sections at Longxian and Yaoxian, North China shows that the youngest Ordovician strata are of the early Katian age corresponding to graptolite Diplacanthograptus spiniferus Biozone. The same level has been recognized to represent the uppermost Ordovician in the plat form area of Tarim, whereas in the marginal belt the top boundary of the Ordovician is slightly younger, corresponding to the graptolite Dicellograptus complanatus Biozone. Thus, the regional uplift in North China and Tarim is shown by the disconformity between the early Katian strata and Late Paleozoic strata, the onset coinciding with that of the Kwangsian Orogeny in South Chi na. The designation Kwangsian Orogeny later fell into disuse and was replaced by the term Caledonian Orogeny. However, in terms of geographic location, tectonic nature, and the timing of activity, the Caledonian Orogeny differs significantly from the orogenic event in South China, and the continued use of this term in South China is inappropriate and misleading.

关 键 词：中国南方 晚奥陶世 构造事件 年龄 塔里木盆地 古生代地层 中国北方 造山运动 

分 类 号：Q911[天文地球—古生物学与地层学] P534.42[生物学—古生物学]