A quantitative analysis of the desiccation and re-filling of the Mediterranean during the Messinian Salinity Crisis
A quantitative analysis of the desiccation and re-filling of the Mediterranean during the Messinian Salinity Crisis
复制标题
墨西拿盐度危机期间地中海干燥和重新填充的定量分析
DOI：
10.1016/j.epsl.2005.09.029
复制
发表时间：
2005
影响因子：
5.3
通讯作者：
W. Krijgsman
中科院分区：
文献类型：
--
作者：
P. Meijer;W. Krijgsman
尽管从观测的角度来看，地中海地区的墨西尼亚蒸发岩受到了大量的关注，但迄今为止，对它们的形成机制还没有达成共识。我们的目标是通过对干燥和再填充过程的定量分析来促进调查。这些过程被认为在蒸发岩层序上部的沉积过程中起了特别的作用。我们计算了海平面和平均盐度的演变基于当前的几何形状和古地理重建，并评估了对淡水收支变化的敏感性。我们的结果支持先前的推论，即干燥和再填充是快速的；干燥发生在3-8凯尔的时间尺度上，重新填充可能更快。平衡的海平面意味着大部分水已经从西部盆地消失，而东部盆地仍有大量水柱。东部盆地是否达到岩盐饱和水平主要取决于，特别是淡水收支。快速的干燥和再填充意味着盆地西部和东部之间以及边缘盆地和盆地中心之间盐降水开始的时间差异低于（天文）测年的分辨率。此外，当大西洋海平面周期性地从低于中间海床的高度到高于中间海床的高度变化时，地中海盆地将以反复的干燥和重新填充来回应。人们发现，快速补充燃料只需要与大西洋建立一个很小的连接。结合之前的结果，这表明地中海不太可能达到稳定的中等水位。
Notwithstanding the great deal of attention that the Messinian evaporites of the Mediterranean region have received from an observational point of view, there is, to date, no consensus as to their mechanism of formation. We aim to contribute to the investigation through a quantitative analysis of the processes of desiccation and re-filling. These processes are thought to have played a role in particular during the deposition of the upper part of the evaporite sequence. We calculate the evolution of sea level and average salinity based on both the present-day geometry and a paleogeographic reconstruction and assess the sensitivity to variations in the freshwater budget. Our results support previous inferences that desiccation and re-filling are fast; desiccation occurs on a time scale of 3–8 kyr, re-filling probably even faster. Equilibrium sea levels imply that most water has gone from the western basin while a significant water column remains in the eastern basin. Whether or not the eastern basin reaches the level of halite saturation depends critically on, in particular, the freshwater budget. The fast rate of desiccation and re-filling imply that temporal differences in the onset of salt precipitation between western and eastern basin and between marginal basins and basin centres are below the resolution of (astronomical) dating. Also, when Atlantic sea level periodically varied from below to above the level of the intervening sill, the Mediterranean basin will have responded with repeated desiccation and re-filling. Fast re-filling is found to require only a small connection to the Atlantic Ocean. This, in combination with the previous results, suggests the Mediterranean is unlikely to attain stable intermediate water levels.