1] Center for Geomicrobiology, Aarhus University, Aarhus 8000, Denmark [2] Bigelow Laboratory for Ocean Sciences, East Boothbay, Maine 04544, USA.
Nat Commun. 2013;4:2539. doi: 10.1038/ncomms3539.
Oceanic crust is the largest potential habitat for life on Earth and may contain a significant fraction of Earth's total microbial biomass; yet, empirical analysis of reaction rates in basaltic crust is lacking. Here we report the first assessment of oxygen consumption in young (~8 Ma) and cool (<25 °C) basaltic crust, which we calculate from modelling dissolved oxygen and strontium pore water gradients in basal sediments collected during Integrated Ocean Drilling Program Expedition 336 to 'North Pond' on the western flank of the Mid-Atlantic Ridge. Dissolved oxygen is completely consumed within the upper to middle section of the sediment column, with an increase in concentration towards the sediment-basement interface, indicating an upward supply from oxic fluids circulating within the crust. A parametric reaction transport model of oxygen behaviour in upper basement suggests oxygen consumption rates of 1 nmol cm(-3)ROCK d(-1) or less in young and cool basaltic crust.
海洋地壳是地球上最大的潜在生命栖息地，可能包含地球总微生物生物量的很大一部分；然而，玄武岩地壳中反应速率的实证分析却很缺乏。在这里，我们报告了对年轻（~8 Ma）和凉爽（<25°C）玄武岩地壳中耗氧量的首次评估，这是我们通过对在中大西洋脊西翼“北池”采集的基岩沉积物中溶解氧和锶孔隙水梯度进行建模计算得出的。在IODP 第 336 航次中收集的。溶解氧完全消耗在沉积物柱的上部到中部，在靠近沉积物-基底界面处浓度增加，表明有含氧流体从地壳内循环向上供应。上部基底中氧行为的参数反应输运模型表明，在年轻和凉爽的玄武岩地壳中，氧消耗率为 1 nmol cm(-3)ROCK d(-1)或更低。
