热带海洋学报 ›› 2012, Vol. 31 ›› Issue (3): 155-161.doi: 10.11978/j.issn.1009-5470.2012.03.020

• 海洋地质学 • 上一篇    

南沙海槽前陆盆地热结构*

马辉1,2, 许鹤华1, 赵俊峰1, 万菊英1,2, 陈爱华1,2, 刘唐伟1,2   

  1. 1.中国科学院边缘海地质重点实验室, 中国科学院南海海洋研究所, 广东 广州 510301;2. 中国科学院研究生院, 北京100049
  • 收稿日期:2010-12-28 修回日期:2011-05-03 出版日期:2012-09-11 发布日期:2012-09-11
  • 作者简介:马辉(1987—), 男, 江西省吉安市人, 硕士研究生, 从事盆地构造演化分析、岩石圈热流变及其数值模拟研究。E-mail : mahui@scsio.ac.cn;许鹤华。E-mail: xhhcn@scsio.ac.cn
    * 感谢中国科学院南海海洋研究所施小斌研究员和杨小秋博士提供热流数据及悉心指导; 也感谢审稿人提出的宝贵意见。
  • 基金资助:

    中国科学院知识创新工程重要方向项目(KZCX2-YW-Q05-04); 国家重点基础研究发展计划项目(2007CB41170405); 中国科学院南海海洋研究所知识创新工程领域前沿项目(LYQY200704); 国家高技术研究发展计划项目(2008AA09Z306)

Thermal structure of Nansha Trough Foreland Basin

MA Hui1,2, XU He-hua1, ZHAO Jun-feng1, WAN Ju-ying1,2, CHEN Ai-hua1,2, LIU Tang-wei1,2   

  1. 1. Key Laboratory of Marginal Sea Geology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; 2. Graduate University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2010-12-28 Revised:2011-05-03 Online:2012-09-11 Published:2012-09-11

摘要: 岩石圈热结构直接影响着岩石的物理性质和流变学性质, 从而制约着岩石圈的形成演化。在研究南沙海槽前陆盆地地质构造背景和岩石圈热结构影响参数基础上, 文章采用一维稳态热传导方程模拟计算并获得了盆地94N05地震剖面岩石圈热结构。计算表明, 盆地区域大地热流平均值约为62mW·m-2; 地幔热流值约37—44mW·m-2, 对地表热流贡献达60%—70%。南沙海槽前陆盆地处于构造热恢复阶段, 地表热流受中中新世挤压构造环境影响相对较低且主要受深部地幔控制, 莫霍面温度介于500—600℃, 热岩石圈较薄, 厚度约60—70km。通过计算岩石圈热结构及居里面深度特征揭示揭示盆地深部岩石圈温度较高以及热活动稳定可能是南沙群岛海域地震发生很少的重要原因。

关键词: 南沙海槽, 大地热流, 生热率, 热导率, 热结构, 地震

Abstract: Thermal structure of continental lithosphere can directly affect physical and rheological properties of rock, thus limiting the evolution of lithosphere. Based on tectonic setting and influencing parameters of lithospheric thermal state in the Nansha Trough Foreland, we numerically simulated lithospheric thermal structure of 94N05 seismic profile in the basin using an one-dimensional steady-state heat-conduction equation. Simulation Results show that average heat flow is about 62 mW·m-2 in the basin, and mantle heat flow is between 37 and 44 mW·m-2, which is up to 60%—70% of the surface heat flow. The Nansha Trough Foreland Basin is in the tectonic thermal recovering phase. Affected by compressional tectonic surroundings since the Miocene, the surface heat flow is relatively low and mainly controlled by deep mantle, and temperature of Moho varies from 500 to 600℃. Thickness of thermal lithosphere is as thin as 60—70 km. This research also reveals that key factors of few regional earthquakes may be related to high temperature and thermal stabilization of the deep lithosphere in the Nansha Islands waters.

Key words: Nansha Trough, heat flow, heat production rate, thermal conductivity, thermal structure, earthquake

中图分类号: 

  • P736.1