Seismic evidence and formation mechanism of gas hydrates in the Zhongjiannan Basin, Western margin of the South China Sea
| Autor: | Genshun Yao, Yintao Lu, Bin Wang, Zhili Yang, Xiwu Luan, Fuliang Lyu, Taotao Yang |
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| Rok vydání: | 2017 |
| Předmět: |
South china
010504 meteorology & atmospheric sciences Stratigraphy Pockmark Clathrate hydrate Trough (geology) Geology Structural basin 010502 geochemistry & geophysics Oceanography 01 natural sciences Methane chemistry.chemical_compound Geophysics chemistry Economic Geology Petrology Seismology 0105 earth and related environmental sciences |
| Zdroj: | Marine and Petroleum Geology. 84:274-288 |
| ISSN: | 0264-8172 |
| DOI: | 10.1016/j.marpetgeo.2017.04.005 |
| Popis: | An analysis of 3D seismic data from the Zhongjiannan Basin in the western margin of the South China Sea (SCS) reveals seismic evidence of gas hydrates and associated gases, including pockmarks, a bottom simulating reflector (BSR), enhanced reflection (ER), reverse polarity reflection (RPR), and a dim amplitude zone (DAZ). The BSR mainly surrounds Zhongjian Island, covering an area of 350 km2 in this 3D survey area. The BSR area and pockmark area do not match each other; where there is a pockmark developed, there is no BSR. The gas hydrate layer builds upward from the base of the stability zone with a thickness of less than 100 m. A mature pockmark usually consists of an outside trough, a middle ridge, and one or more central pits, with a diameter of several kilometers and a depth of several hundreds of meters. The process of pockmark creation entails methane consumption. Dense faults in the study area efficiently transport fluid from large depths to the shallow layer, supporting the formation of gas hydrate and ultimately the pockmark. |
| Databáze: | OpenAIRE |
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