近2ka以来东海内陆架泥质区记录的高分辨率古气候演化

Recent 2000 a climatic record of mud area on the inner shelf of the East China Sea

通过对位于东海内陆架泥质区中部的MZ02柱样岩芯进行粒度、常量元素、AMS14C分析,获得了粒度和常量元素随时间变化的高分辨率曲线。结果表明,近2 ka以来研究区沉积环境稳定,以沿岸流控制的浅海沉积为主,沉积物中CaO/K2O,MgO/Al2O3和MnO/Na2O比值的变化与我国东部气候变化序列具有较好的一致性,证明这些元素地球化学指标可以作为古气候变化的高分辨率替代性指标。近2 ka以来CaO/K2O、MgO/Al2O3和MnO/Na2O共同识别出的7次极值揭示了同期的降温事件,分别发生在～1 480 a BP(C1),～1 200 a BP(C2),～1 020 a BP(C3),～780 a BP(C4),～580 a BP(C5),～330 a BP(C6),～120 a BP(C7),且在其他区域不同介质中也能找到相应的降温证据,揭示了气候变化的区域性以至全球性联系。

Recent 2000 a environmental record of Core MZ02,recovered in the center of mud area on the inner continental shelf of the East China Sea,reflecting a low-energy shallow sea shelf depositional environment dominated by the coastal currents.The temporal variation of most geochemical element percentages corresponds to the climate inferred from historical record,i.e.,the relatively low values of MgO/Al2O3,CaO/K2O and high value of MnO/Na2O generally concur with the warm and humid climate,and vice versa.This geochemical response suggests the potential application of these proxies in the interpretation of palaeoclimate variation of eastern China.Recent 2000 a climatic variation history is reconstructed for the inner continental shelf of the East China Sea,and there are at least seven low-temperature events during this period,which occur in ～1 480 a BP（C1）,～1 200 a BP（C2）,～1 020 a BP（C3）,～780 a BP（C4）,～580 a BP（C5）,～330 a BP（C6） and ～120 a BP（C7）.All the cooling events are corroborated by other proxies in various areas,which show that regional and even global relationship of climate changes exist.