Temperature seasonality control on modern halite layers in the Dead Sea; in situ observations
Temperature seasonality control on modern halite layers in the Dead Sea; in situ observations
复制标题
死海现代岩盐层的温度季节性控制；
DOI：
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
N. Lensky
中科院分区：
文献类型：
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作者：
I. Sirota;Y. Enzel;N. Lensky
在整个地质记录中，在深盆地中发现了层状岩盐层。然而，这些序列的类似物通常在浅层环境中进行研究。在这里，我们研究了盐岩层的活跃降水，这些盐岩层来自深盐沉积盆地的唯一现代模拟物，即高盐死海。在死海的现场观测联系了季节性热盐层、岩盐饱和度和活跃形成的岩盐层的特征。通过逐月观测(1)湖温盐层（温度、盐度和密度），(2)盐饱和度，(3)活动盐岩沉积物的结构演化，表征了死海盐岩降水的时空演化特征。我们提出了观测到的层状岩盐沉积的结构特征（即粒度、固结和粗糙度）与饱和度之间的关系，这反过来反映了湖泊学和水文气候学。湖底被划分为两个主要环境：深湖底、浅湖底和浅湖底。在较深的低渗湖底，岩盐不断沉淀，并有季节变化：(1)夏季，固结的粗大岩盐晶体在轻度过饱和度下形成粗糙表面。(2)冬季，松散的细粒岩盐晶体在高过饱和状态下形成光滑的湖底沉积物。这些观测结果支持对岩盐结晶机制的季节交替的解释。浅层沉积湖底受季节温度变化和前一年部分岩盐沉积夏季强烈溶蚀的影响较大，形成薄层序，年际不整合。这强调了温度季节性对沉淀岩石层特征的控制。此外，浅成矿底板上的岩盐沉淀，牺牲了浅成矿底板的溶蚀作用，导致盆地深处的岩盐沉积侧向集中和增厚，而浅部边缘盆地的岩盐沉积则变薄。
Layered halite sequences are found in deep basins throughout the geological record. However, analogs for such sequences are commonly studied in shallow environments. Here, we studied active precipitation of halite layers from the only modern analog for deep, halite-precipitating basins, the hypersaline Dead Sea. In situ observations in the Dead Sea link seasonal thermohaline stratification, halite saturation, and the characteristics of the actively forming halite layers. The spatiotemporal evolution of halite precipitation in the Dead Sea was characterized by means of monthly observations of (1) lake thermohaline stratification (temperature, salinity, and density), (2) degree of halite saturation, and (3) textural evolution of the active halite deposits. We present the observed relationships between the textural characteristics of layered halite deposits (i.e., grain size, consolidation, and roughness) and the degree of saturation, which in turn reflects the limnology and hydroclimatology. The lake floor is divided into two principal environments: a deep, hypolimnetic lake floor and a shallow, epilimnetic lake floor. In the deeper hypolimnetic lake floor, halite continuously precipitates with seasonal variations: (1) During summer, consolidated coarse halite crystals form rough surfaces under slight supersaturation. (2) During winter, unconsolidated, fine halite crystals form smooth lake floor deposits under high supersaturation. These observations support interpretations of the seasonal alternation of halite crystallization mechanisms. The shallow epilimnetic lake floor is highly influenced by the seasonal temperature variations, and by intensive summer dissolution of part of the previous year’s halite deposit, which results in thin sequences with annual unconformities. This emphasizes the control of temperature seasonality on the characteristics of the precipitated halite layers. In addition, precipitation of halite on the hypolimnetic floor, at the expense of the dissolution of the epilimnetic floor, results in lateral focusing and thickening of halite deposits in the deeper part of the basin and thinning of the deposits in shallow marginal basins.
来自死海深部沉积物微相分析的黎凡特末次冰期早期（～ 117â75 ka）期间的水文气候变化
影响因子：
4.3
作者：
Neugebauer;Schwab;Waldmann;Tjallingii;Hadzhiivanova;Naumann;A. Brauer
通讯作者：
A. Brauer
ICDP 死海深钻项目 (DSDDP) 恢复的长沉积物记录的岩性
影响因子：
4
作者：
Neugebauer;Brauer;Schwab;Waldmann;Kitagawa;Torfstein;Dulski;Ariztegui;Ben-Avraham;Goldstein
通讯作者：
Goldstein