Characteristics and Research of Heat Flow in the Northwest Sub-Basin and Its Adjacent Areas of the South China Sea
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摘要: 西北次海盆是南海海盆的一个重要构造单元,揭示西北次海盆的地热流特征对于整体认识南海海盆热状态和热结构至关重要.沿着OBS2006-1地震剖面采集的一批实测地热流数据显示,该热流探测剖面横穿南海北部陆坡、西北次海盆、中沙隆起、东部次海盆4个构造单元,结合地震解释剖面等资料对西北次海盆进行地热流特征分析及研究.结果表明:西北次海盆的平均热流密度值为104.5±9.9 mW/m2,与中沙隆起相邻的东部次海盆北部的平均热流密度值为97±2.5 mW/m2,热流密度值的空间变化与地幔埋深起伏相对应,并受地幔热源所控制;通过研究热流异常点,发现水深相近的相邻站位之间的海底表层沉积物温度差异是判别测站受海底地下水热循环影响程度和类型的依据之一;用最新海洋地热流探测成果,结合区域地质与地球物理资料,推测西北次海盆形成演化时代与西南次海盆相近,只是它的生命史比较短暂.Abstract: The Northwest sub-basin (NW sub-basin) is an important tectonic unit in the South China Sea. It is of great importance to reveal the geothermal characteristics of the NW sub-basin for the better understanding of thermal and thermal structures of the basins of South China Sea. We have collected a series of measured heat flow data along the OBS2006-1 seismic profile. This heat flow profile crosses four tectonic units, including the northern slope of the South China Sea, the NW sub-basin, the Zhongsha rise and the east sub-basin. With the seismic interpretation profile, this paper analyzes and studies in detail the heat flow characteristics. The results show that the average heat flow value is 104.5±9.9 mW/m2 in the NW sub-basin, and the average heat flow value in the northern part of the East sub-basin is 97±2.5 mW/m2, the change trend of the heat flow values is similar to that of the Moho depth, which manifests that the deep thermal state is controlled by the source of mantle heat. By studying the anomalies of heat flow, it is found that the temperature difference between the seabed surface sediments in adjacent sites is one of the basis for judging the degree and type of groundwater thermal cycling. With the latest ocean heat flow detection results, combined with regional geology and geophysical data, it is suggested that the formation of the NW sub-basin is similar to that of the Southwest sub-basin, but with relatively shorter history.
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Key words:
- Northwest sub-basin /
- heat flow /
- oceanic crust /
- age /
- geophysics
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图 2 沿SO49-18剖面的热流剖面
据Ding et al.(2012);吴振利等(2011)修改
Fig. 2. The heat flow profile along SO49-18 profile
图 4 海盆热流-洋壳年龄关图
a.Parsons and Sclater(1977)的洋壳年龄与热流关系;b.实测热流与Briais et al.(1993)洋壳年龄关系曲线
Fig. 4. The relationship diagram of ocean basin heat flow and oceanic crust age
表 1 HYIV20160829航次中的地热流测量结果
Table 1. The results of heat flow measurements in HYIV20160829 expedition
站名 北纬(°) 东经(°) 水深(m) 海底水温(℃) 地温梯度(℃/km) 热导率(W/mK) 热流密度值(mW/m2) 探测深度(m) L01 19.083 5 114.350 1 1 341 3.364 73.7 0.936 68.9 4.0 L02 18.583 3 114.600 1 3 620 2.342 140.8 0.797 112.2 4.0 L03 18.316 8 114.716 7 3 644 2.337 133.0 0.801 106.5 4.0 L04 18.083 5 114.816 8 3 705 2.372 10.1 0.810 8.2 4.0 L04-1 18.050 0 114.833 5 3 700 2.369 58.5 0.806 47.2 4.0 L05 17.850 0 114.950 1 3 708 2.365 135.4 0.851 115.2 4.0 L06 17.566 8 115.066 8 3 703 2.370 113.6 0.820 93.1 4.0 L07 17.333 5 115.166 7 2 198 2.521 85.7 0.826 70.7 4.0 L08 17.100 1 115.300 1 2 336 2.449 29.6 0.826 24.4 4.0 L09 16.816 8 115.416 7 3 956 2.396 111.5 0.885 98.7 4.0 L10 16.583 4 115.550 1 4 077 2.418 116.1 0.820 95.2 4.0 L11-1 16.500 0 115.616 7 4 109 2.410 157.7 0.909 143.4 4.0 L12 18.000 0 114.583 5 3 585 2.363 117.8 0.811 95.5 4.0 L13 18.200 1 114.766 8 3 625 2.354 18.4 0.808 14.9 4.0 注:表中地温梯度值已经过角度校正,热导率值已经过温压校正. -
Anderson, R. N., Langseth, M. G., Hayes, D. E., et al., 1978. Heat Flow, Thermal Conductivity, Thermal Gradient, A Geophysical Atlas of East and Southeast Asian Seas. In: Hayes, D. E., ed., Map Chart Ser. MC-25. Geological Society of America, Boulder. Ao, W., Zhao, M.H., Qiu, X.L., et al., 2012.Crustal Structure of the Northwest Sub-Basin of the South China Sea and Its Tectonic Implication.Earth Science, 37(4):779-790 (in Chinese with English abstract). https://doi.org/10.3799/dqkx.2012.087 Barckhausen, U., Roeser, H. A., 2004. Seafloor Spreading Anomalies in the South China Sea Revisited. Continent-Ocean Interactions within East Asian Marginal Seas, AGU Chapman Conference, San Diego. Briais, A., Patriat, P., Tapponnier, P., 1993.Updated Interpretation of Magnetic Anomalies and Seafloor Spreading Stages in the South China Sea:Implications for the Tertiary Tectonics of Southeast Asia.Journal of Geophysical Research:Solid Earth, 98(B4):6299-6328. https://doi.org/10.1029/92jb02280 Ding, W.W., Li, M.B., Zhao, L.H., et al., 2009.Cenozoic Tectono-Sedimentary Characteristics and Extension Model of the Northwest Sub-Basin, South China Sea.Earth Science Frontiers, 16(4):147-156(in Chinese with English abstract). http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=dxqy-e201104003 Ding, W.W., Schnabel, M., Franke, D., et al., 2012.Crustal Structure across the Northwestern Margin of South China Sea:Evidence for Magma-Poor Rifting from a Wide-Angle Seismic Profile.Acta Geologica Sinica(English Edition), 16(4):854-866. http://kns.cnki.net/kcms/detail/detail.aspx?dbcode=CJFD&filename=DZXW201204007&dbname=CJFD2012 Fang, N.Q., Yao, B.C., Wan, L., et al., 2007.The Velocity Structure of the Lithosphere and the Origin of Sedimentary Basins in the South China and Northern Margin of the South China Sea.Earth Science, 32(2):147-154 (in Chinese with English abstract). http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=dqkx200702001 He, L.J., Xiong, L.P., Wang, J.Y., et al., 1998.The Geothermal Characteristics in the South China Sea.China Offshore Oil and Gas (Geology), 12(2):87-90(in Chinese with English abstract). http://d.old.wanfangdata.com.cn/Periodical/dqwlxb201807021 Hyndman, R. D., Erickson, A. J., Von Herzen, R. P., 1974. Geothermal Measurement on DSDP Leg 26 In: Davies, T. A., Luyendyk, B. P., eds., Initial Reports of the Deep Sea Drilling Project 26, Washington, 675-742. Li, C.F., Xu, X., Lin, J., et al., 2014.Ages and Magnetic Structures of the South China Sea Constrained by Deep Tow Magnetic Surveys and IODP Expedition 349.Geochemistry, Geophysics, Geosystems, 15(12):4958-4983. doi: 10.1002/2014GC005567 Luo, X.H., Xu, X., Shi, X.B., et al., 2008.Principle and Method of Submarine Sediment Thermal Conductivity Measurement in Laboratory with TK04 Thermal Conductivity Measurement System as Example.Ocean Technology, 27(2):88-91(in Chinese with English abstract). http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=hyjs200802020 Nissen, S.S., Hayes, D.E., Yao, B.C., et al., 1995.Gravity, Heat Flow, and Seismic Constraints on the Processes of Crustal Extension:Northern Margin of the South China Sea.Journal of Geophysical Research:Solid Earth, 100(B11):22447-22483. https://doi.org/10.1029/95jb01868 Parsons, B., Sclater, J.G., 1977.An Analysis of the Variation of Ocean Floor Bathymetry and Heat Flow with Age.Journal of Geophysical Research, 82(5):803-827. https://doi.org/10.1029/jb082i005p00803 Qian, Y.P., 1982.Terrestrial Heat Flow Measurements and the Results in the North of South China Sea.Marine Geological Research, 2(4):102-107(in Chinese with English abstract). http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=QK000001530784 Ratcliffe, E.H., 1960.The Thermal Conductivities of Ocean Sediments.Journal of Geophysical Research, 65(5):1535-1541. https://doi.org/10.1029/jz065i005p01535 Ru, K., Pigott, J.D., 1986.Episodic Rifting and Subsidence in the South China Sea.AAPG Bulletin, 70(9):1136-1155. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=CAS201303040000263646 Shi, X.B., Qiu, X.L., Xia, K.Y., et al., 2003.Heat Flow Characteristics and Its Tectonic Significance of South China Sea.Journal of Tropical Oceanography, 22(2):63-73(in Chinese with English abstract). http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=rdhy200302007 Taylor, B., Hayes, D. E., 1983. Origin and History of the South China Sea Basin. In: Hayes, D. E., ed., The Tectonic and Geologic Evolution of Southeast Asian Seas and Islands, Geophysical Monograph Series. 27: 23-56. Wang, J.Y., Xiong, L.P., Huang, S.P., 1996.Heat Transfer and Groundwater Activity in Sedimentary Basins.Quaternary Sciences, 16(02):147-158(in Chinese with English abstract). http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=QK199600050691 Wu, Z.L., Li, J.B., Ruan, A.G., et al., 2011.Crustal Structure of the Northwestern Sub-Basin, South China Sea:Results from a Wide-Angle Seismic Experiment.Science in China(Series D)(in Chinese). http://kns.cnki.net/KCMS/detail/detail.aspx?filename=JDXG201201017&dbname=CJFD&dbcode=CJFQ Xu, X., Luo, X.H., X, B., 2005.Research on the Methods & Technique of Marine Heat Flow Measurement.Ocean Technology, 24(1):77-81(in Chinese with English abstract). http://en.cnki.com.cn/Article_en/CJFDTOTAL-HYJS200501018.htm Xu, X., Shi, X.B., Luo, X.H., et al., 2006.Data Processing of Geothermal Measurements in the Northern Margin of the South China Sea.Geoscience, 20(3):457-464(in Chinese with English abstract). http://en.cnki.com.cn/Article_en/CJFDTOTAL-XDDZ200603013.htm Xu, X., Shi, X.B., Luo, X.H., et al., 2006.Heat Flow Measurements in the Xisha Trough of the South China Sea.Marine Geology & Quaternary Geology, 26(4):51-58(in Chinese with English abstract). http://en.cnki.com.cn/Article_en/CJFDTotal-HYDZ200604010.htm Yao, B.C., 1999.Tectonic Characteristics of Northwest Sub-Basin and Seafloor Spreading History of South China Sea in Cenozoic.Tropic Oceanology, 18(1):7-15(in Chinese with English abstract). http://en.cnki.com.cn/article_en/cjfdtotal-rdhy199901001.htm Yao, B.C., Zeng, W.J., Chen, Y.Z., et al., 1994.The Crustal Structure in the Eastern Part of the Northern Margin of the South China Sea.Chinese Journal of Geophysics, 37(1):27-35 (in Chinese with English abstract). http://en.cnki.com.cn/Article_en/CJFDTotal-DQWX401.003.htm 敖威, 赵明辉, 丘学林, 等, 2012.南海西北次海盆及其邻区地壳结构和构造意义.地球科学, 37(4):779-790. https://doi.org/10.3799/dqkx.2012.087 丁巍伟, 黎明碧, 赵俐红, 等, 2009.南海西北次海盆新生代构造-沉积特征及伸展模式探讨.地学前缘, 16(4):147-156. doi: 10.3321/j.issn:1005-2321.2009.04.014 方念乔, 姚伯初, 万玲, 等, 2007.华南和南海北部陆缘岩石圈速度结构特征与沉积盆地成因.地球科学, 32(2):147-154. doi: 10.3321/j.issn:1000-2383.2007.02.001 何丽娟, 熊亮萍, 汪集旸, 等, 1998.南海盆地地热特征.中国海上油气(地质), 12(2):87-90. http://d.old.wanfangdata.com.cn/Periodical/dqwlxb201402021 罗贤虎, 徐行, 施小斌, 等, 2008.室内海底沉积物热导率测量的原理与方法——以TK04热导率测量系统为例.海洋技术, 27(2):88-91. doi: 10.3969/j.issn.1003-2029.2008.02.020 钱翼鹏, 1982.南海北部地热流测量及其成果.海洋地质研究, 2(4):102-107. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=QK000001530784 施小斌, 丘学林, 夏戡原, 等, 2003.南海热流特征及其构造意义.热带海洋学报, 22(2):63-73. doi: 10.3969/j.issn.1009-5470.2003.02.007 汪集旸, 熊亮萍, 黄少鹏, 1996.沉积盆地中热的传递和地下水活动.第四纪研究, 16(2):47-158. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=QK199600050691 吴振利, 李家彪, 阮爱国, 等, 2011.南海西北次海盆地壳结构:海底广角地震实验结果.中国科学(D辑), (10):1463-1476. http://d.old.wanfangdata.com.cn/Periodical/dqkx201204016 徐行, 罗贤虎, 肖波, 2005.海洋地热流测量技术及其方法研究.海洋技术, 24(1):77-81. doi: 10.3969/j.issn.1003-2029.2005.01.019 徐行, 施小斌, 罗贤虎, 等, 2006a.南海北部海底地热测量的数据处理方法.现代地质, 20(3):457-464. http://d.old.wanfangdata.com.cn/Periodical/xddz200603014 徐行, 施小斌, 罗贤虎, 等, 2006b.南海西沙海槽地区的海底热流测量.海洋地质与第四纪地质, 26(4):51-58. http://d.old.wanfangdata.com.cn/Periodical/hydzydsjdz200604008 姚伯初, 1999.南海西北海盆的构造特征及南海新生代的海底扩张.热带海洋, 18(1):7-15. doi: 10.3969/j.issn.1009-5470.1999.01.002 姚伯初, 曾维军, 陈艺中, 等, 1994.南海北部陆缘东部的地壳结构.地球物理学报, 37(1):27-35. doi: 10.3321/j.issn:0001-5733.1994.01.004