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(单词翻译:双击或拖选)
Rice had seen the same thing in Iceland, one of the few places on Earth with similarities to Mars. It too is extremely cold, and most of the water is frozen into glaciers2. And also like Mars, buried underground, are massive volcanoes. This powerful combination has shaped the entire landscape. When a volcano erupts, lakes of steaming melt water form high up on top of the glacier1 until the enormous weight of water forces its way down, bursting out from the base of the glacier. These are the biggest floods on Earth, a surging wall of water stretching for kilometers. In their wake they leave vast planes littered with boulders4. To a geologist5 these boulder3 fields contain unmistakable evidence of the floodwaters that ripped through here.
Okay, well this is really a classic textbook example, these two large boulders here. The size of them indicates this was an enormous flood that deposited these features, but also if you look at their geometry, these boulders are kind of dipping back in this direction. This has given us information about the path that floodwaters took that deposited these boulders. The floodwaters were going in this direction when these rocks were deposited. Now there is other interesting things in the scene here. For instance, notice some of these smaller rocks are very well rounded, and these little nicked corners of these boulders here, these are kind of percussion6 marks and these are produced in a water, highly turbulent water column when the boulders and rocks are basically slamming into one another, knocking the corners off. These things all grouped together just tell you there’s no doubt this was a catastrophic flood deposit.
The pictures from Mars showed the rocks in exactly the same pattern as on Iceland. Here were the slanting7 boulders lined up by the floodwaters. And the cameras on the rover provided detailed8 views of the individual rocks, with their telltale chipped edges. It seemed that the vast Martian channels had been carved by enormous floods. It was final confirmation9 that Mars had once been warm and wet like the Earth, and that meant that there really was every chance for life to have evolved there.
deposit:(动词)to lay down or leave behind by a natural process
(名词)Something deposited, especially by a natural process, as:
a: Geology. A concentration of mineral matter or sediment10 in a layer, vein11, or pocket
b: Physiology12. An accumulation of organic or inorganic13 material, such as a lipid or mineral, in a body tissue, structure, or fluid.
c: A sediment or precipitate14 that has settled out of a solution.
1 glacier | |
n.冰川,冰河 | |
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2 glaciers | |
冰河,冰川( glacier的名词复数 ) | |
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3 boulder | |
n.巨砾;卵石,圆石 | |
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4 boulders | |
n.卵石( boulder的名词复数 );巨砾;(受水或天气侵蚀而成的)巨石;漂砾 | |
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5 geologist | |
n.地质学家 | |
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6 percussion | |
n.打击乐器;冲突,撞击;震动,音响 | |
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7 slanting | |
倾斜的,歪斜的 | |
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8 detailed | |
adj.详细的,详尽的,极注意细节的,完全的 | |
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9 confirmation | |
n.证实,确认,批准 | |
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10 sediment | |
n.沉淀,沉渣,沉积(物) | |
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11 vein | |
n.血管,静脉;叶脉,纹理;情绪;vt.使成脉络 | |
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12 physiology | |
n.生理学,生理机能 | |
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13 inorganic | |
adj.无生物的;无机的 | |
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14 precipitate | |
adj.突如其来的;vt.使突然发生;n.沉淀物 | |
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