南沙西部海区构造沉降与古热流

THE TECTONIC SUBSIDENCE AND HEAT FLOW OF THE WESTERN NANSHA AREA

盆地的构造沉降和热流演化具有密切的联系。分析南沙西部海区万安、曾母盆地岩石圈结构现今特征认为,该区可应用多幕拉伸的纯剪切裂谷盆地模型恢复盆地热流历史。通过计算机技术的动态模拟,表明该区盆地演化过程中存在多个快速沉降期;其古热流总体上由低到高变化,但在不同的演化阶段表现不同,有升高也有降低,同时也反映了构造运动对热流变化的影响。该研究成果为深入研究盆地的沉积物充填演化和油气的生成过程提供了条件。

There is a close relation between the tectonic subsidence and the heat flow in basins. The heat flow history may be recovered by using the model of pure shearing, multi - stage stretching rift basin in the lithosphere structure for the present Wanan and Zengmu basins in the western Nansha area. By using the computerized dynamic modeling, the authors show that some quickly subsiding stages were involved in the process of basin formation, and the heat flow value generally varied from low to high as a whole, despite the fact that it may show alternatively increasing and decreasing trends at different stages, which demonstrates that the tectonic movement affected the heat flow value significantly. The authors believe that this research would be useful for going deep into analyzing the sediment accumulation and hydrocarbon generation processes in the basins.