Rock Types and Sedimentary Environment of the Ma51+2 Carbonates in Northeastern Ordos Basin
doi: 10.14027/j.cnki.cjxb.2016.05.010
- Received Date: 2016-04-22
- Rev Recd Date: 2016-06-08
- Publish Date: 2016-10-10
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Key words:
- rock types /
- sedimentary environment /
- grain beach /
- Ma51+2 /
- northeastern Ordos Basin
Abstract: Affected by multi-period karst cumulated influence, the original rock fabric of Ma51+2 member of Ordovician in the northeastern Ordos basin have suffered a great destruction which restricted the reconstructing study of original palaeoenvironment and sedimentary facies. Based on core, thin section, cathode luminescence and the recovery of the protolith, five original rock types and seven rock products of diagenesis are recognized, and it can be divided into five rock type combinations, which represents about five sedimentary environment in restricted and evaporate platform of study area in the following:grain beach, beach interaction sea, mound-shoal complex, platform inner flat and restricted lagoon. Those rock type combinations constitutes four typical sedimentary sequences in vertical which reflects a drop in sea level, including restricted lagoon- platform inner shoals- platform inner flat and restricted lagoon- mound-shoal complex- platform inner flat. The results show that the grainstones and gypsum mould pore contained mud(bread flour)-crystal dolomitite form the two major kinds of original rock types in Ma51+2 member of Ordovician in northestern Ordos basin, a certain scale of algal binding rock and mud(bread flour)-crystal dolomitite are also found. Besides, the gypsum mould pore contained mud(bread flour)-crystal dolomitite shows a close relationship with the upward shoaling succession of mounds and shoals. These new recognition can provide the basis for in-depth study of palaeoenvironment and reservoir rocks in the study area.
Citation: | LIU XinShe, XIONG Ying, WEN CaiXia, LI Ling, WANG FeiYan, HE Wei, YANG QingYu, XIAO Di, TAN XiuCheng. Rock Types and Sedimentary Environment of the Ma51+2 Carbonates in Northeastern Ordos Basin[J]. Acta Sedimentologica Sinica, 2016, 34(5): 912-923. doi: 10.14027/j.cnki.cjxb.2016.05.010 |