JOURNAL OF PALAEOGEOGRAPHY ›› 1999, Vol. 1 ›› Issue (3): 13-18. doi: 10.7605/gdlxb.1999.03.003

• LITHOFACIES PALAEOGEOGRAPHY • Previous Articles     Next Articles

PALAEOGEOGRAPHIC IMPLICATIONS OF CARBONIFEROUS TO PERMIAN OOLITIC LIMESTONES IN THE
CHANGNING MENGLIAN BELT OF WEST YUNNAN

Yan Jiaxin  Liu Benpei  Zhang Haiqing   

  1. China University of Geosciences, Wuhan 430074
    China University of Geosciences, Beijing 100083
    China National Geological and Mining Corporation, Beijing 100083
  • Online:1999-06-01 Published:1999-06-01
  • About author:Yan Jiaxin was born in 1962, and graduated from the Department of Geology of Wuhan Geological College in 1983. Now he is an associate professor and engaged in sedimentology and palaeoclimatology at the Department of Earth Sciences in China University of Geosciences (Wuhan).

滇西昌宁—孟连带内石炭纪—二叠纪鲕粒灰岩的古地理意义

颜佳新  刘本培 张海清   

  1. 中国地质大学，武汉430074
    中国地质大学，北京100083
    中国地质矿业总公司，北京100083
  • 作者简介:颜佳新，男， 1962年生。1983年毕业于武汉地质学院地质系，现为中国地质大学（武汉）副教授，主要从事沉积学、古气候学教学和研究工作。

Abstract:

Although the radiolarian cherts of Devonian to Middle Triassic of deep water origin have been reported from the Changning Menglian belt (CMB) in west Yunnan Province, the tectono  palaeogeographic nature of the CMB is still in controversy. The confirmation of the oolitic limestones of the Late Carboniferous to the Early Permian Age in the CMB of west Yunnan Province implied the carbonate succession was accumulated in a shallow and agitating environment, possibly as the carbonate caps of oceanic islands. The formation of the carbonate ooids also indicated the ambient water of warm nature under the semi arid palaeoclimatic background. The analysis of geological context showed that the carbonate succession was formed in the southern subtropical semi arid paleo climate zone, in contrast to the time equivalents to the both sides of the CMB. The Changning Menglian ocean thus was the main branch of the Palaeo Tethyan ocean separated the blocks of Gondwana affinities from those of Cathaysian affinities, and situated in the southern subtropical semi arid palaeoclimatic zone and spanned about 10° in palaeolatitude in the Late Carboniferous to the Early Permian Age.

摘要：

虽然在滇西昌宁—孟连带内发现了泥盆纪至中三叠世的放射虫硅质岩，但是目前对其构造古地理意义仍然有争议。对昌宁—孟连带晚石炭世至早二叠世碳酸盐岩地层内鲕粒灰岩进行了研究，结果表明，该套碳酸盐岩形成于动荡浅水沉积环境，其成因可能与古特提斯洋内碳酸盐岩洋岛海山有关，并且反映了温暖、较为干燥的古气候背景。根据地质背景资料分析，它们应该形成于南亚热带较干燥的气候环境。与东西两侧同期地层形成的古气候背景对比发现，在石炭纪—二叠纪时，昌宁—孟连带是分隔滨冈瓦纳地块群和华夏地块群的主支洋盆；在早二叠世时，该洋盆宽度约10°古纬距。