Noble gases in sediment pore water yield insights into hydrothermal fluid transport in the northern Guaymas Basin
Noble gases in sediment pore water yield insights into hydrothermal fluid transport in the northern Guaymas Basin
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DOI：
10.1016/j.margeo.2021.106419
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发表时间：
2021-01-28
期刊：
影响因子：
2.9
通讯作者：
Kipfer, R.
中科院分区：
文献类型：
--
作者：
Horstmann, E.;Tomonaga, Y.;Kipfer, R.
我们提供了在最近发现的热液喷口地点附近的深海沉积物孔隙水中测定的稀有气体浓度，该热液喷口地点由土丘结构和几个黑烟囱组成，位于加利福尼亚湾瓜伊马斯盆地北部。使用稀有气体作为示踪剂来识别沉积物孔隙空间内流体的来源，并深入了解该区域热液的输运动态。我们的数据表明，瓜伊马斯盆地底水是靠近热液喷口场的中上层沉积体孔隙水的唯一来源。特别是，没有证据表明热液通过黑烟系统周围的深海沉积物进行直接（扩散或平流）输送。这一发现意味着，在这个黑色吸烟者地点，热液从吸烟者下方非常狭窄的通道中的流体源向上输送。因此，流体仅通过黑烟囱的烟囱直接注入海洋，周围沉积物不会产生额外的排放。氦同位素数据显示，在过去喷口场更加活跃的阶段（据称代表 5-6 年前黑烟客的早期爆发），具有不同同位素特征的底层水被纳入沉积物柱中。
We present noble gas concentrations determined in pore water of deep-sea sediments close to a recently discovered hydrothermal vent site, consisting of a mound structure and several black smokers, located in the northern Guaymas Basin, Gulf of California. Noble gases were used as tracers to identify the origin of fluids within the sediment pore space and to gain insight into transport dynamics of hydrothermal fluids in this region. Our data suggest that Guaymas Basin bottom water is the only source of pore water in the pelagic sediment body close to the hydrothermal vent field. In particular, there is no evidence of any direct (diffusive or advective) transport of hydrothermal fluids through the deep-sea sediments surrounding the black smoker system. This finding implies that at this black smoker site hydrothermal fluids are transported upwards from the fluid source in very narrow pathways below the smokers. Thus, the fluids are only injected into the ocean directly through the chimneys of the black smokers and no additional emission from the surrounding sediment takes place. Helium isotope data show that during a more active phase of the vent field in the past (supposedly representing the early onset of the black smokers 5-6 kyrs ago), bottom water with a different isotopic signature was incorporated into the sediment column.