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风尘中所含的铁是海洋生物的营养元素,对浮游生物的生产力有重要影响,从而对海洋吸收CO_2的量有调节作用,进而影响全球气候。从亚洲内陆产生的粉尘不仅堆积于黄土高原,形成黄土-古土壤序列,而且落入北太平洋等海域。基于黄土高原中部的西峰和长武两个剖面,对900ka以来风尘的铁含量及其时域变化特征进行分析,结果表明,不同时期的风尘铁含量具有明显的变化。铁含量的波动总体上与冰期-间冰期旋回的变化差异较大,不具明显的100 ka的周期,而具有较强的准20 ka的周期和清晰的准40 ka周期,显示北半球太阳辐射的变化对风尘铁含量有明显的控制作用。900 ka以来,S5-1古土壤(深海氧同位素阶段13)的铁含量最高,对应于900 ka以来大洋碳同位素值最高的时期,表明该事件具有全球性的意义。
Iron contained in the dust is a nutrient element of marine organisms and has a significant impact on the productivity of plankton, thus regulating the amount of CO 2 absorbed by the oceans and thus affecting the global climate. Dust generated from inland Asia not only accumulates in the Loess Plateau, forming loess-paleosol sequences, but also falls into the Pacific Ocean and other areas. Based on the two sections of Xifeng and Changwu in the central part of the Loess Plateau, the iron content and the time-domain variation characteristics of dust and dust since 900 ka have been analyzed. The results show that the iron content of dust and dust has obvious changes in different periods. The fluctuation of iron content is generally different from that of the glacial-interglacial cycles. There is no obvious period of 100 ka, but the strong quasi-20 ka period and the clear quasi-40 ka period show the variation of solar radiation in the northern hemisphere Dust dust iron content has a significant role in the control. Since 900 ka, S5-1 paleosol (the deep-sea oxygen isotope phase 13) has the highest iron content, corresponding to the highest carbon isotopic value since 900 ka, indicating that this event is of global significance.