Age models for pelagites and turbidites from the Cap Timiris Canyon off Mauritania
Age models for pelagites and turbidites from the Cap Timiris Canyon off Mauritania
复制标题
毛里塔尼亚蒂米里斯角峡谷的白云岩和浊积岩的年龄模型
DOI：
10.1016/j.marpetgeo.2005.10.005
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发表时间：
2006
影响因子：
4.2
通讯作者：
H. Schulz
中科院分区：
文献类型：
--
作者：
K. Wien;C. Holz;M. Kölling;H. Schulz
这项对蒂米里斯海角峡谷沉积物的研究表明，即使是高度混浊的岩心，地球化学数据也可以提供可靠的年龄深度对比，并试图提高我们对浊积岩侵位与气候相关海平面变化之间联系的理解。该峡谷切割了非洲西北部的大陆边缘，是浑浊洋流的活跃通道。在堤防和隧道内场地的沉积物岩心中，浊积岩占沉淀柱的6%-42%。一旦从数据集中去除浊积层，通过将岩心下部元素数据与过时的参考岩心相关联，将年龄模型拟合到所有研究的岩心。这些年龄模型使我们能够确定浊积岩的侵位时间。蒂米里斯海角峡谷至少在过去的245年里一直很活跃，浊流沉积似乎与阶段边界和冰川阶段有关。高混浊岩芯的形成时代为≈15kyr，由全新世和晚更新世沉积组成。该地点的浊积岩沉积尤其与更新世/全新世过渡时期海平面的快速上升有关。全新世，浑浊流活动减弱，但并未停止。
This study of sediments from the Cap Timiris Canyon demonstrates that geochemical data can provide reliable age-depth correlation even of highly turbiditic cores and attempts to improve our understanding of how turbidite emplacement is linked to climatic-related sea-level changes. The canyon incises the continental margin off NW Africa and is an active conduit for turbidity currents. In sediment cores from levee and intrachannel sites turbidites make up 6–42% of sediment columns. Age models were fitted to all studied cores by correlating downcore element data to dated reference cores, once turbidite beds had been removed from the dataset. These age models enabled us to determine turbidite emplacement times. The Cap Timiris Canyon has been active at least over the last 245kyr, with turbidite deposition seemingly linked to stage boundaries and glacial stages. The highly turbiditic core from the intrachannel site postdates to≈15kyr and comprises Holocene and late Pleistocene sediments. Turbidite deposition at this site was associated especially with the rapid sea-level rise at the Pleistocene/Holocene transition. During the Holocene, turbidity current activity decreased but did not cease.