沉积物镁铝含量比及其古气候意义  

Relationship between Mg-Al ratio in sediment and paleoclimate

作　　者：张士三[1] 陈承惠[1] 黄衍宽[1] 

机构地区：[1]国家海洋局第三海洋研究所,厦门361005

出　　处：《台湾海峡》1993年第3期266-271,共6页Journal of Oceanography In Taiwan Strait

摘　　要：沉积物的镁铝含量比——m 值(m=100×MgO/Al_2O_3)与沉积水介质的盐度、pH 水温关系密切。当水温处在冰点以下时,沉积物的m 值随水温降低而增大。当水温处在冰点以上时,水介质的盐度、pH 和水温的增加,都有利于m 值增大。由于气候条件能直接或间接地影响沉积水介质的特征,因此,沉积物的m 值对古气候的变化具有一定的判别功能。通过对中国元古宙以来沉积物m 值的分析,发现古气候的热冷变化有1200Ma 的周期,其中还有次一级的热冷气候波动。第四纪的气候是处在热气候期后期的一个冷的气候波动阶段。The Mg-Al content ratio of sediment,namely m value(m=100×MgO/Al_2O_3)is close-ly related to salinity,pH and temperature of water in the sedimentation processes.If watertemperature is below the ice point,the m value of sediment increases with the drop of tem-perature.If water temperature is over the ice point,the increase of salinity,pH and temper-ature in water facilitates the increase of the m value.Because the climatic condition can affect directly or indirectly the feature of water in thesedimentation processes,the m value of sediment has a certain discriminating function forthe paleoclimatic changes.According to the analysis of the m value of sediments since the Proterozoic,it is foundthat the hot-cold changes of the paleoclimate has a period of 1 200Ma with hot-cold fluctua-tions in different amplitudes.The Quaternary is just in a cold stage of such a climatic fluctu-ation in the later part of the hot climatic period.

关 键 词：沉积物 镁 铝 含量比 古气候 

分 类 号：P736.43[天文地球—海洋地质]