Palaeoclimatic cyclicity in central Mediterranean Pliocene sediments:: the mineralogical signal
Palaeoclimatic cyclicity in central Mediterranean Pliocene sediments:: the mineralogical signal
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DOI：
10.1016/s0031-0182(00)00056-0
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发表时间：
2000-05-15
影响因子：
3
通讯作者：
Mélières, F
中科院分区：
文献类型：
--
作者：
Foucault, A;Mélières, F
对地中海中部4个上新世沉积剖面(西西里岛Punta Piccola；卡拉布里亚蒙特辛加和Vrica；爱奥尼亚海964A孔)的高分辨率X射线矿物学研究表明，两组粘土矿物的丰度呈周期性相反的变化。第一种主要是坡缕石和高岭石，它们的丰度极大值可以解释为非洲大陆干旱时期的结果，允许它们作为风吹来的尘埃运输。第二种以蒙皂石为主，其丰度极大值可解释为地中海边界地区雨量充沛的时期。这些丰度的变化显示出22Ky的周期性，这意味着受地球轨道进动的控制。腐泥层和腐泥层总是出现在富蒙脱石的岩层中，因此似乎是在湿润时期沉积的。(C)2000 Elsevier Science B.V.保留所有权利。
A high resolution X-ray mineralogical study of four Pliocene sediment sections from the central Mediterranean (Punta Piccola, Sicily; Monte Singa and Vrica, Calabria; ODP Hole 964 A, Ionian Sea) shows cyclic opposite abundance variations of two groups of clay minerals. The first is dominated by palygorskite and kaolinite, whose abundance maxima can be interpreted as resulting from periods of aridity on the African continent, allowing their transport as wind-blown dust. The second is dominated by smectite, whose abundance maxima can be interpreted as indicative of periods of abundant rainfall on the Mediterranean borderlands. These variations in abundance show a 22 ky cyclicity, implying a control by the precession of the Earth's orbit. Sapropels and sapropelic layers always occur in the smectite-rich beds, and therefore appear to have been deposited during the wet periods. (C) 2000 Elsevier Science B.V. All rights reserved.