| WANG Zhenfeng,SHI Xiaobin,YANG Jun,HUANG Baojia,SUN Zhen,WANG Yahui,JIANG Haiyan,YU Chuanhai,YANG Xiaoqiu. 2014. Analyses on the tectonic thermal evolution and influence factors in the deep-water Qiongdongnan Basin. Acta Oceanologica Sinica, 33(12):107－117 |
| Analyses on the tectonic thermal evolution and influence factors in the deep-water Qiongdongnan Basin |
| 琼东南盆地深水区构造热演化特征及其影响因素分析 |
| Received:June 20, 2014 Revised:September 29, 2014 |
| DOI：10.1007/s13131-014-0580-9 |
| Key words:northern continental margin South China Sea surface heat flow magmatism |
| 中文关键词: 北部大陆边缘 南海 海底热流 岩浆作用 |
| 基金项目:the National Science and Technology Major Programs of China under contract No. 2011ZX05025-002-01; the National Natural Science Foundation of China under contract Nos 41176050 and 41376059. |
| Author Name | Affiliation | E-mail | | WANG Zhenfeng | Zhanjiang Branch of China National Offshore Oil Corporation (CNOOC) Limited, Zhanjiang 524057, China | | | SHI Xiaobin | Key Laboratory of Marginal Sea Geology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China | xbshi@scsio.ac.cn | | YANG Jun | Key Laboratory of Marginal Sea Geology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
University of Chinese Academy of Sciences, Beijing 100039, China | | | HUANG Baojia | Zhanjiang Branch of China National Offshore Oil Corporation (CNOOC) Limited, Zhanjiang 524057, China | | | SUN Zhen | Key Laboratory of Marginal Sea Geology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China | | | WANG Yahui | Zhanjiang Branch of China National Offshore Oil Corporation (CNOOC) Limited, Zhanjiang 524057, China | | | JIANG Haiyan | Key Laboratory of Marginal Sea Geology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China | | | YU Chuanhai | Key Laboratory of Marginal Sea Geology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
University of Chinese Academy of Sciences, Beijing 100039, China | | | YANG Xiaoqiu | Key Laboratory of Marginal Sea Geology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China | |
|
| Hits: 2061 |
| Download times: 2444 |
| Abstract: |
| To reveal the tectonic thermal evolution and influence factors on the present heat flow distribution, based on 154 heat flow data, the present heat flow distribution features of the main tectonic units are first analyzed in detail, then the tectonic thermal evolution histories of 20 profiles are reestablished crossing the main deep-water sags with a structural, thermal and sedimentary coupled numerical model. On the basis of the present geothermal features, the Qiongdongnan Basin could be divided into three regions: the northern shelf and upper slope region with a heat flow of 50-70 mW/m2, most of the central depression zone of 70-85 mW/m2, and a NE trending high heat flow zone of 85-105 mW/m2 lying in the eastern basin. Numerical modeling shows that during the syn-rift phase, the heat flow increases generally with time, and is higher in basement high area than in its adjacent sags. At the end of the syn-rift phase, the heat flow in the deepwater sags was in a range of 60-85 mW/m2, while in the basement high area, it was in a range of 75-100 mW/m2. During the post-rift phase, the heat flow decreased gradually, and tended to be more uniform in the basement highs and sags. However, an extensive magmatism, which equivalently happened at around 5 Ma, has greatly increased the heat flow values, and the relict heat still contributes about 10-25 mW/m2 to the present surface heat flow in the central depression zone and the southern uplift zone. Further analyses suggested that the present high heat flow in the deep-water Qiongdongnan Basin is a combined result of the thermal anomaly in the upper mantle, highly thinning of the lithosphere, and the recent extensive magmatism. Other secondary factors might have affected the heat flow distribution features in some local regions. These factors include basement and seafloor topography, sediment heat generation, thermal blanketing, local magmatic injecting and hydrothermal activities related to faulting and overpressure. |
| 中文摘要: |
| 为揭示琼东南盆地深水区构造热演化及现今热流分布特征的影响因素,本文依据154个热流数据,首先详细分析了主要构造单元热流分布特征,并通过20条骨干剖面的构造热演化数值分析,重建了主要深水凹陷的热演化过程.结果表明:琼东南盆地热流分布可以分为3个区域:北部陆架与上陆坡区具有较低的热流,热流值介于50-70 mW/m2,中央坳陷带大部分深水区,热流值一般介于70-85 mW/m2,盆地东部宝岛、长昌凹陷与西沙海槽北部斜坡带有一条热流值大于85 mW/m2的高热流带;张裂阶段区域热流总体上随时间增加,凸起区热流一般高于凹陷区内热流,张裂结束时,深水凹陷区热流介于65-85mW/m2,凸起区热流更高介于75-100 mW/m2;裂后阶段,盆地热流逐渐降低,凸起区和凹陷区热流差异变小,等效于5Ma左右发生的晚期岩体侵位热事件使中央坳陷带和南部隆起带的热流大幅升高,现今该热事件仍贡献约10-25mW/m2.进一步分析表明,琼东南盆地深水区高热流特征主要是在上地幔高热背景、岩石圈强烈减薄的基础上叠加了晚期岩浆侵入热事件的结果.局部热流分布还受到盆地基底形态、海底地形、沉积物热贡献、沉积物热披覆效应、局部岩体侵入以及超压、断裂引起的流体活动等因素影响. |
|
HTML
View Full Text
View/Add Comment Download reader |
| Close |
|
|
|
