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通过南海北部陆坡ODP1144孔沉积柱状样的炭屑数量统计,结合花粉资料讨论了南海北部大陆及大陆架上1 Ma以来天然火的历史及其与气候的关系．研究表明,炭屑的数量及大小与搬运距离有关；搬运距离越短,炭屑数量越多,而粗粒炭屑与细粒炭屑的相对比值也越大．冰期时(氧同位素偶数期)炭屑沉积率均很高,粗粒炭屑与细粒炭屑比值较大；间冰期时(氧同位素奇数期)炭屑沉积率相对较低,粗粒炭屑与细粒炭屑比值较小．这表明冰期时炭屑主要来源于出露的大陆架,炭屑源区与沉积地点距离缩短；间冰期时大陆架被淹没,炭屑只能来源于南海北部周边大陆,炭屑搬运距离增长．整个钻孔剖面碳屑沉积速率变化规律表明在0．9,0．47和0．13 Ma前后,天然火发生强度都有明显增强,表明这些时段气候发生明显变化,可能与青藏高原的阶段性隆起有关．频谱分析表明,1 Ma以来碳屑沉积速率变化明存在99．1,41 ka的轨道周期以及10 ka(12～8 ka)的半岁差周期．半岁差周期的存在也反应了热带低纬过程对气候变化的影响．
The history of natural fire in the northern continental shelf and continental shelf of the South China Sea and its relationship with climate were discussed based on the data of the number of carbonaceous sediments deposited on column ODP1144 in the northern slope of the South China Sea and the pollen data. The research shows that the amount and size of carbon scraps are related to the transportation distance. The shorter the transportation distance is, the more carbon scraps are, and the larger the relative ratio of coarse carbon and fine carbon is. During the glacial period, the deposition rate of carbon was very high, and the ratio of coarse carbon to fine carbon was large. During the interglacial (oxygen isotope odd number), the deposition rate of carbon was relatively low, The smaller the ratio of fines and charcoal. This indicates that during the glacial period, the charcoal mainly came from the exposed continental shelf, and the distance between the carbon source and the sedimentary site was shortened. During the interglacial period, the continental shelf was submerged, and the charcoal could only come from the surrounding continent in the northern part of the South China Sea. The regularity of carbon deposition rate in the entire borehole section shows that the intensity of natural fire intensified significantly before and after 0.9, 0.47 and 0.13 Ma, indicating that the climate changed obviously during these periods, which may be related to the stage of the Qinghai-Tibet Plateau Uplift related. Spectrum analysis shows that the change of carbon deposition rate since 1 Ma shows that the orbital period of 99.1 and 41 ka and the semi-precession period of 10 ka (12 and 8 ka), respectively. The existence of semi-precession period also reflects the impact of tropical low-latitude processes on climate change.