Tectono-thermal evolution features of the reef body developing area in the Liyue Basin, southern South China Sea
文献类型：期刊论文
| 作者 | Wang LiFang1; Shi XiaoBin2,3,4; Ren ZiQiang2,5; Pei JianXiang1; Yang XiaoQiu2,3,4; Shen YongQiang2,5; Shi DeFeng1; Liu Kui2,5; Zhao Peng2,5; Yan AnJu1 |
| 刊名 | CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION
 |
| 出版日期 | 2020 |
| 卷号 | 63期号:8页码:3050 |
| 关键词 | Reed bank Thermal status Thermal history Heat flow Vitrinite reflectance |
| DOI | 10.6038/cjg2020N0410 |
| 英文摘要 | Reed Bank is an important tectonic unit of the Liyue Basin, and has been developing reefs since drifting from the northern continent margin in the Late Oligocene. To understand the thermal state and thermal evolution features of these long term submerged reefs and underlying strata, we first made a detailed analyses on borehole temperature and vitrinite reflectance data, then modeled numerically the tectono-thermal evolution history of a typical profile just passing through a reef body of the Reed Bank. The results show that the borehole temperature in the depth interval of 2000 similar to 4500 m in the reef ranges from 30 degrees C to 90 C , and the thermal gradient between the seafloor and the measured depth is only about 10 degrees C.km(-1). The geothermal gradient increases gradually with depth, and the thermal gradient is about 32 similar to 37 degrees C.km(-1) between 3000 and 4000 m. The maximum paleo-temperature that organic matter below the reef body has experienced should be much higher than their present environmental temperature. Further analyses suggests that due to heat exchange with the surrounding low temperature seawater, the upper part of the reefs with high porosity and high permeability is cooled, and seafloor thermal gradient and heat flow are greatly reduced, even to be negative. As the heat exchange with surrounding seawater became weak, and finally disappear with increasing depth, formation temperature gradually increases, and geothermal gradient and heat flow tend to be normal. The borehole geothermal gradient in the depth range of 3000 similar to 4000 m is about 35 degrees C.km(-1), and the estimated heat flow across sedimentary basement is in the range of 65 and 75 mW.m(-2), with an average of 70 mW.m(-2). The organic matter maturity was mainly obtained just before the reefs began to exchange heat effectively with the surrounding low temperature seawater, and then with heat exchange between reef and seawater, thermal maturity of the organic matter has been increased slowly with decreasing formation temperature. As a result, the threshold depth of oil generation in the reef body developing area is much larger than that in the central region of the Bei 1 sag. |
| 源URL | [http://ir.scsio.ac.cn/handle/344004/18531]  |
| 专题 | 南海海洋研究所_中科院边缘海地质重点实验室 |
| 作者单位 | 1.CNOOC, Hainan Energy Ltd, Haikou 570100, Hainan, Peoples R China 2.CNOOC Ltd, Zhanjiang Branch, Zhanjiang 524057, Guangdong, Peoples R China 3.Chinese Acad Sci, South China Sea Inst Oceanol, Key Lab Ocean & Marginal Sea Geol, Guangzhou 510301, Peoples R China 4.Chinese Acad Sci, Innovat Acad South China Sea Ecol & Environm Engn, Guangzhou 510301, Peoples R China 5.Southern Marine Sci & Engn Guangdong Lab Guangzho, Guangzhou 510301, Peoples R China 6.Univ Chinese Acad Sci, Beijing 100049, Peoples R China |
| 推荐引用方式 GB/T 7714 | Wang LiFang,Shi XiaoBin,Ren ZiQiang,et al. Tectono-thermal evolution features of the reef body developing area in the Liyue Basin, southern South China Sea[J]. CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION,2020,63(8):3050, 3062. |
| APA | Wang LiFang.,Shi XiaoBin.,Ren ZiQiang.,Pei JianXiang.,Yang XiaoQiu.,...&Yan AnJu.(2020).Tectono-thermal evolution features of the reef body developing area in the Liyue Basin, southern South China Sea.CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION,63(8),3050. |
| MLA | Wang LiFang,et al."Tectono-thermal evolution features of the reef body developing area in the Liyue Basin, southern South China Sea".CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION 63.8(2020):3050. |
入库方式： OAI收割
来源：南海海洋研究所
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