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通过南海北部陆坡ODP1144孔(20°3′N, 117°25′E, 水深2037 m)沉积柱状样的炭屑数量统计, 结合有关花粉资料讨论了南海北部大陆及大陆架上最近3个冰期旋回中天然火的历史及其与气候的关系. 依据1144孔炭屑、花粉研究结果, 可以将0-225 m的地层划分为8个带(C1-C8带), 分别与深海氧同位素1-8期相对应, 其中C2-4带为末次冰期, C6, C8带分别为倒数第二次和第三次冰期. 研究表明, 1144孔深海沉积物冰期时(MIS 2, 4, 6, 8期)炭屑沉积率均很高, 说明冰期时大陆和大陆架上天然火发生的强度很高, 反映当时气候较为干旱. 尽管MIS 6期和8期细粒炭屑沉积率较高, 表明大陆上天然火强度较大, 当时气候较为干燥; 但粗、中粒炭屑沉积率却相对较低, 可能与MIS 5期以前大陆架出露范围较小, 导致中、粗粒炭屑的源区较小有关. 间冰期时(MIS 1, 5, 7期)炭屑沉积率相对较低, 一方面是由于大陆架被海水淹没, 炭屑来源较少; 另一方面, 也说明天然火的强度有大幅度下降, 气候由干旱转为湿润. 尽管MIS 3期细粒炭屑沉积率有所降低, 但中粗粒炭屑沉积率与4期相当, 表明当时大陆架上天然火强度依然很大, 气候较为干燥.
Based on the statistics of sedimentary columnar charcoals deposited on the northern slope of the South China Sea (ODP1144) (20 ° 3’N, 117 ° 25’E, 2037 m depth) and the related pollen data, the recent three glacial cycles in the continental and continental shelf of the South China Sea The history of natural fire and its relationship with climate According to the results of 1144 pores and pollen, 0-225 m strata can be divided into 8 zones (C1-C8 zones) The C2-4 belt is the last glacial stage, while the C6 and C8 belt are the second and third last glacial time respectively. The results show that the sediments of 1144-hole deep sea (MIS 2, 4, 6, 8) The high sedimentation rate indicates that the intensity of natural fire on the continental shelf and the continental shelf during the glacial period was very high, reflecting a more arid climate at that time.Although the deposition rates of MIS 6 and 8 fine-grained charcoal were high, it shows that the natural fire intensity While the climate was drier at that time. However, the deposition rate of coarse and medium-sized carbon was relatively low, which may be related to the smaller exposure range of the continental shelf before MIS 5, which resulted in the smaller source area of coarse-grained carbon. During the glacial (MIS 1, 5, 7) carbon deposition rate is relatively low, on the one hand is due to the mainland On the other hand, it shows that the strength of natural fire has dropped dramatically and the climate changes from arid to wet.Although the sedimentation rate of MIS 3 fine-grained charcoal decreased, The deposition rate of charcoal was comparable to that of phase 4, indicating that the natural fire intensity on the continental shelf was still high at that time and the climate was relatively dry.