Researches on tempestites of the Member 2 and Member 3 of Lower
Permian Xiashihezi Formation in Daniudi Gasfield,Ordos Basin
Lin WenJiang Zaixing Xiang Shu an You Guoqing Tian Jijun
1 School of Energy Resources, China University of Geosciences(Beijing), Beijing100083
2 Institute of Geology,Chinese Academy of Geological Sciences,Beijing100037
This paper firstly proposed that tempestites were developed in the Members 2 and 3 of Lower Permian Xiashihezi Formation in the Daniudi Gasfield in the Ordos Basin. The previous studies indicated that the two members were dominated by fluvial sedimentary system. However,the discovery of tempestites proved that lacustrine facies was also developed in the study area. During the deposition of the Members 2 and 3,the lake was wide and shallow,the topography was gentle, and shallow lacustrine facies was developed. Storm currents are easily formed in this setting. On the basis of core observation and granularity analyses, sedimentary structures of tempestites were identified and they were widely developed in the study area. They include truncated structure,gutter cast,hummocky crossbedding and scouring surface etc. The cumulative probability curves and sedimentary structures reflect that the transportation medium was characterized by the combination of tractive current and gravity flow. The ideal vertical sequence of the tempestites in the study area is a Boumalike sequence,namely as: A,graded and massive bedding segment; B,parallel bedding segment; C,hummocky cross bedding segment; D,Ripple bedding segment; E,mudstone segment. The tempestite is a typical marker of lacustrine facies,therefore,the proposition of tempestites gives some new viewpoints in identifying sedimentary facies types of the study area and has an important significance for reconstructing the palaeogeography of the Xiashihezi Formation.
About author: Lin Wen,born in 1980,is a candidate for PhD. degree in China University of Geosciences (Beijing).
Cite this article:
. Researches on tempestites of the Member 2 and Member 3 of Lower
Permian Xiashihezi Formation in Daniudi Gasfield,Ordos Basin[J]. JOURNAL OF PALAEOGEOGRAPHY, 2008, 10(2): 167-174.
. Researches on tempestites of the Member 2 and Member 3 of Lower
Permian Xiashihezi Formation in Daniudi Gasfield,Ordos Basin[J]. JOPC, 2008, 10(2): 167-174.