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首页> 外文期刊>Earth and Planetary Science Letters: A Letter Journal Devoted to the Development in Time of the Earth and Planetary System >Speleothems and paleoglaciers
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Speleothems and paleoglaciers

机译：脾科和古冰川

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Ice and speleothems are widely regarded as mutually exclusive as the presence of liquid water is a fundamental prerequisite for speleothem deposition. Here we show that speleothems may form in caves overlain by a glacier, as long as the temperature in the cave is above freezing and the conduits are not completely flooded by melt water. Carbonate dissolution is accomplished via sulfide oxidation and the resultant speleothems show high delta C-13 values approaching and locally exceeding those of the parent host rock (lack of soil-derived biogenic C). The delta O-18 values reflect the isotopic composition of the melt water percolating into the karst fissure network and carry an atmospheric (temperature) signal, which is distinctly lower than those of speleothems formed during periods when soil and vegetation were present above the cave. These 'subglacial' speleothems provide a means of identifying and dating the former presence of warm-based paleoglaciers and allow us to place some constraints on paleotemperature changes. (c) 2006 Elsevier B.V. All rights reserved.
机译：由于液态水的存在是蛇麻草沉积的基本前提，因此冰和蛇麻草被广泛认为是互斥的。在这里，我们表明，只要洞穴中的温度高于冰点并且管道没有被融化的水完全淹没，洞穴就可能在冰川覆盖的洞穴中形成。碳酸盐的溶解是通过硫化物的氧化作用完成的，而所得的鞘脂显示出较高的δC-13值，该值接近并局部超过了母体岩石（缺乏土壤衍生的生物碳）。 δO-18值反映了渗入喀斯特裂隙网络的融化水的同位素组成，并带有大气（温度）信号，该信号明显低于在洞穴上方存在土壤和植被的时期形成的鞘脂的信号。这些“冰期以下”的脾地热提供了一种方法，可以识别和测算以前存在的温暖的古冰川，并允许我们对古温度的变化施加一些限制。 （c）2006 Elsevier B.V.保留所有权利。

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