【摘要】 中国南海北部蕴藏着丰富的油气资源，分析该区域中新世古气候，对其油气资源开发有着极其重要的意义。综合运用Matlab软件频谱分析及滤波方法深入分析南海北部珠江口盆地惠陆低凸起中部A井1 949.12～2 020 m自然伽马测井数据（GR）的天文年代标尺，精确推测出对应时间段的古气候事件，并分析造成此事件的原因。研究结果显示，该GR数据序列的功率谱显示出68.8、16.99、7.81、3.74 m厚度的沉积旋回周期，其中，68.8 m和16.99 m厚度的沉积旋回分别对应405 ka的长偏心率周期信号和100 ka的短偏心率周期信号；7.81 m的沉积旋回对应46 ka的斜率周期信号；3.74 m的沉积旋回对应22 ka的岁差周期信号。由此表明，A井的沉积地层记录了天文轨道信号（偏心率、斜率、岁差）。根据建立的天文年代标尺确定整个韩江组地质年龄约为10.2～16.5 Ma，推测出14～15 Ma期间可能由于偏心率振幅降低发生了冷却事件。更多还原

【Abstract】 Rich oil and gas resources occur in the northern South China Sea. To analyze the Miocene paleoclimate is of great significance to oil and gas exploration in the region. In this paper, spectrum analysis and filtering method of the Matlab software are used to process the natural gamma logging curves from 1 949.12 m to 2 020 m of the Well A in the middle of the Huilu Low Uplift of the Pearl River Mouth Basin, and the paleoclimatic events in corresponding time periods are accurately predicted and the origins of the events revealed. The results suggest that the power spectrum of the GR data series shows depositional cycles of 68.8 m, 16.99 m, 7.81 m and 3.74 m.And it is deduced that the deposition cycles of 68.8 m and 16.99 m correspond to the long eccentricity signal of405 ka and the short eccentricity signal of 100 ka, respectively. The deposition cycle of 7.81 m corresponds to the slope periodic signal of 46 ka, and the deposition cycle of 3.74 m corresponds to the precession periodic signal of22 ka. The deposits penetrated by the well recorded perfectly the astronomical orbital signals(eccentricity, slope,precession). According to the established astronomical chronology, the geological age of the whole Hanjiang Formation is approximately in the range of 10.2～16.5 Ma, and a cooling event may have occurred between 14Ma and 15 Ma due to the decrease in eccentricity amplitude.更多还原