Characteristics and Environmental Significance of the Sinian Dengying Formation Oncoids in the Northeastern Sichuan Basin
doi: 10.14027/j.issn.1000-0550.2018.090
- Received Date: 2017-09-18
- Rev Recd Date: 2017-12-16
- Publish Date: 2018-04-10
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Key words:
- Sinian Dengying Formation /
- Oncoids /
- characteristics /
- controlling factors /
- sedimentary environment
Abstract: Oncoids occur in Sinian Dengying Formation in Ziyang Maliu region of Sichuan Basin. Using the field geological survey, the polarizing microscope and field emission scanning electron microscopy (SEM) to study oncoids of morphology, structure, sedimentary environment and the main control factors, the result is as follows:oncoids are developed in the middle and upper of the four section of the Dengying Formation, they can be divided into four categories:TypeⅠnormal oncoid, Type Ⅱnormal compound oncoid, Type Ⅲ thin skin oncoid, Type Ⅳ thin skin compound oncoid, and given priority to with Type Ⅰ. Oncoids of morphology are given priority to with spherical, and few ellipsoid, bar and irregular shape of oncoids. The conditions of the forming of oncoids are sufficient material basis in Sinian Dengying Formation, appropriate middle-high energy hydrodynamic conditions and the injection of low terrigenous clastic material. Research shows that the sedimentary environment of the oncoids in the middle and upper of the four section of the Dengying Formation is in a medium-high energy shallow gentle slope belt.
Citation: | TANG Xuan, LIU ShuGen, SONG JinMin, LI ZhiWu, YU YongQiang, LONG Yi, ZAN BoWen, ZHAO Cong. Characteristics and Environmental Significance of the Sinian Dengying Formation Oncoids in the Northeastern Sichuan Basin[J]. Acta Sedimentologica Sinica, 2018, 36(2): 232-242. doi: 10.14027/j.issn.1000-0550.2018.090 |