Stratigraphic Sequence and Sedimentary Systems in the Middle-Southern Continental Slope of the East China Sea from Seismic Reflection Data: Exploration Prospects of Gas Hydrate
Stratigraphic Sequence and Sedimentary Systems in the Middle-Southern Continental Slope of the East China Sea from Seismic Reflection Data: Exploration Prospects of Gas Hydrate
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从地震反射资料看东海中南部陆坡地层层序和沉积体系：天然气水合物勘探前景
DOI：
10.1007/s11802-019-3845-2
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发表时间：
2019-09
影响因子：
1.6
通讯作者：
Wang Jinkai
中科院分区：
文献类型：
--
作者：
Li Deyong;Chen Hongyan;Xu Shujuan;Xing Junhui;Cheng Honggang;Wang Jinkai
东海陆坡区存在天然气水合物沉积的证据很多，如海底模拟反射、海底气泉、与甲烷渗漏有关的黄铁矿、泥底辟/泥火山、海底甲烷异常等。T_2（25.8 Myr）、T_3（53.3 Myr）、T_4（11.02 Myr）和T_5（16.12 Myr）被鉴定出来，并划分出5个SQIII 1-SQIII 5三级序列。而南部陆坡没有发现T_5，表明冲绳海槽中北部早在中新世早期就开始裂陷，早于南部陆坡。进一步划分了低水位体系域、水进体系域、高水位体系域和下降期体系域4个体系域。11.02 Myr的海蚀界面和23 kyr B. P.的海退不整合界面表明研究区发生了两次大规模的海平面下降事件。在大陆坡区识别出7种典型的地震相，分别是陆架边缘三角洲、沿岸的河流三角洲平原、下切河道或海底峡谷、斜坡扇、海底扇或海岸沙洲、滨浅海细粒沉积、泥火山和其它地质体。冲绳海槽天然气水合物赋存的最小水深为630 m，陆坡天然气水合物稳定带厚度在0 ~ 590 m之间。计算出的水合物稳定带底部边界略深于地震剖面上的海底反射带。第四系地层中发育的峡谷水道、斜坡扇、海底扇等再沉积浊积岩砂体是主要的水合物储集层。根据水合物系统的发育过程，可将其动态成藏过程划分为3个演化阶段：峡谷侵蚀与水合物稳定带运移阶段、沉积物失稳与甲烷渗漏阶段、河道充填与水合物再生成阶段。
Many evidences for gas hydrate bearing sediments had been found in the continental slope of the East China Sea, such as bottom simulating reflections (BSRs), undersea gas springs, pyrite associated with methane leakage, mud diapirs/mud volcanos, bottom-water methane anomalies and so on. In this study, six key stratigraphic interfaces including T_0 (seafloor), T_1 (LGM, 23 kyr B.P.), T_2 (2.58 Myr), T_3 (5.33 Myr), T_4 (11.02 Myr) and T_5 (16.12 Myr) were identified, and then five third-order sequences of SQIII1 to SQIII5 were divided. However, T_5 in southern continental slope is not found, which shows that the middle-northern Okinawa Trough had begun to rift in the early Miocene, earlier than the southern segment. Four system tracts including lowstand systems tract (LST), transgressive systems tract (TST), highstand systems tract (HST) and falling stage systems tract (FSST) are further divided. The marine erosion interface of 11.02 Myr and regressive unconformity interface of 23 kyr B.P. indicate two large-scale sea level drop events in the research area. Seven typical seismic facies identified in the continental slope are continental shelf-edge deltas, littoral fluvial-delta plains, incised channels or submarine canyons, slope fans, submarine fans or coastal sandbars, littoral-neritic finegrained sediments, mud volcanos and some other geological bodies respectively. The minimum water depth for hydrate occurrence in the Okinawa Trough is 630 m, and the thickness of gas hydrate stability zone in continental slope is between 0 and 590 m. The calculated bottom boundary of hydrate stability zone is slightly deeper than BSRs on the seismic sections. The re-depositional turbidite sand bodies, such as canyon channels, slope fans and submarine fans developed in Quaternary strata, are the predominant hydrate reservoirs. According to developing process, the dynamic accumulation of hydrate systems can be divided into three evolutionary stages including canyon erosion and hydrate stability zone migration stage, sediments destabilizing and methane leakage stage, and channel filling and hydrate re-occurrence stage.
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DOI：
10.1111/j.1755-6724.2010.00164.x
发表时间：
2010-01
期刊：
Acta Geologica Sinica ‐ English Edition
影响因子：
--
作者：
Youhai Zhu;Yongqing Zhang;H. Wen;Zhenquan Lu;Zhi-Qing Jia;Yonghong Li;Qinghai Li;Changling Liu-Changling-Li
通讯作者：
Youhai Zhu;Yongqing Zhang;H. Wen;Zhenquan Lu;Zhi-Qing Jia;Yonghong Li;Qinghai Li;Changling Liu-Changling-Li
影响因子：
3
作者：
Dawei Lv;Jitao Chen
通讯作者：
Dawei Lv;Jitao Chen
影响因子：
56.9
作者：
A. Koppers;H. Staudigel
通讯作者：
A. Koppers;H. Staudigel
DOI：
--
发表时间：
2000
期刊：
--
影响因子：
--
作者：
Meng Xian
通讯作者：
Meng Xian
DOI：
--
发表时间：
2008
期刊：
--
影响因子：
--
作者：
Wu Bi-hao
通讯作者：
Wu Bi-hao