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是什么让水从地球陷入?

我记得在什么地方读火星上有水的证据,但一切都陷入了火星土壤。防止地球上发生了什么?

有些人说这是因为地壳不渗透水,但这必须是无稽之谈,因为火山的行动和地震,肯定会出现裂缝,让水流淌。所以唯一阻止水下沉的是温度,对吧?

回答

>防止地球上发生了什么?并不多。相当多的水是循环地壳和地幔。>所以唯一阻止水下沉的是温度,对吧?这是故事的一部分。对于我们的讨论,水可以以两种形式存在:——分子水2 H <子> < /订阅> O,在几个阶段之一(液体水,固体冰,超临界流体,水蒸气),——结构水在固体矿产。例如,在粘土矿物即泥浆。高岭土的矿物组成泥浆(或灰尘),公式Al <子> < /订阅>如果<子> 2 < /订阅> 5 O <子> < /订阅> (OH) < /订阅> <子> 4。看到(OH) <子> 4 < /订阅>吗?这基本上就是水。 Even if you take a pile of mud, dry it at 110 °C in an oven until it's completely dry, the water is still going to be in there. Molecular water can react with rocks and minerals to form hydrous minerals and get trapped as structural water (similar to adding water to Portland cement in the making of concrete), and hydrous minerals can be heated enough to release this water (usually requiring hundreds of degrees). Let's look at some examples of how this thing might work. Oceans have mid ocean ridges, where the oceanic lithosphere is being formed. This area has very shallow magma chambers so the rock is extremely hot. Water that percolates down through cracks gets heated to a large degree, lowering the density and increasing the buoyancy of the water. This water then goes back up through hydrothermal vents on the seafloor. Here's a spectacular video of some of those things: https://www.youtube.com/watch?v=rTR6gGDWcJk When the water goes down, not all of it goes back up. It also reacts with the rock, forming hydrous minerals. For example, anorthite (CaAl2Si2O8), a common mineral in basalts, is hydrated to epidote-clinozoisite: Ca2Al3Si3O12(OH). In some occasions, oceanic crust can be uplifted and is then exposed. One example is Cyprus, where you can see features like this: [![enter image description here][1]][1] What you're looking at is basically anhydrous rocks (the white stuff) replaced by hydrous minerals (the brown stuff) due to upwelling hot water in the oceanic crust. Above it, now gone, was a hydrothermal vent like the ones in the video. On land, water does sink deep down as well. As Gordon mentioned in his answer, water is common in oil reservoirs, but it's just about anywhere else. It is particularly rich in sedimentary rocks, that still have some amount of the liquid water that existed during sediment deposition (river, lagoon, lake, etc). A good property of water in subsurface conditions, is that at higher temperature and pressure it can dissolve and leach metals from rock. This provides a way to move metals around, eventually depositing these metals in localised locations so we can exploit them. Lead, zinc and gold are examples of metals that can be concentrated by circulating water. Water can also go deep down into the mantle in subduction zones. Water trapped in pore spaces and hydrous minerals can sink hundreds of kilometres down into the Earth. Eventually, the temperature becomes too hot to sustain the water in there and the rock devolatilise: they lose the water (which is a supercritical fluid at this stage). This water is then incorporated into magmas, and erupted in volcanoes. In many volcanoes, especially in arc volcanoes (such as the ones around the Pacific ocean), a major component of "volcanic gas" is actually water vapour. To sum it up, water goes down, water goes up. It's all one huge happy cycle. [1]: http://i.stack.imgur.com/Zv8aA.jpg

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