听力原文 现在我们已经知道由于冰川的作用，使得峡谷变的更加开阔，成了U字形。但是地理运动仍在继续，落基山脉的南端已经形成了一个巨大的裂痕。究竟是什么原因造成了这样的情况？请听今天的落基山系列第15期，希望您能找到答案。

It stretches over 160,000 square miles and is known as the Real Grand Valley. Geologists are eager to investigate how this giant rifting valley could affect the future of the Rockies.

They find their first lead in San Ysidro, New Mexico, north of Albuquerque. The area is dominated by bright yellow porous rock known as travertines. Curiously, geologists think this rock forms from water.

"This water has some unusual characteristics, that is, this water is capable of precipitating （ 沉淀）or depositing any rock or travertine. It is like, kind of, like the scale in your teapot."

Travertine rock is made out of calcite, the same material that builds up lime scale. These rocks grow very rapidly. Some enlarge by a few inches per month.

"About a liter of the water will be able to drop out or precipitate a little pile of calcite about as big as an aspirin tablet."

Like lime scale building up in a hot water kettle, travertines form around warm springs. Measurements confirmed that water temperature around the travertine is roughly 77 degrees. Besides the ability to build rock, this hot water has more secrets to tell.

Laura Crossey and Karl Karlstrom have a hunch that the water is warmed up by heat from the earth’s interior, rising up through cracks in the rock. They form as the Rift Valley pulls apart. Climbing down a cape 25 feet below the surface, they are hoping to find further evidence. The water contains microbes. They are microscopically small organisms. Most of them consist of only one cell. When scientists analyze their genes in the lab, they found something remarkable.

"What we’ve found in springs like this by doing the DNA analysis is that the microbes that are coming up these faults are much more like what we find at mid-ocean ridges （海洋中间的山脊）than like the rivers and streams we could expect in the continental setting."

小编有约：这一期的落基山脉中出现了 travertines。" The scientific explanation is the hot thermal places that lie under the mount provoke the calcium carbonate spill, that makes the forms as solid as travertine marble."（科学的解释是位于山底下的地热引起碳酸钙析出，使之形成晶体般的石灰岩。）咱们烧开水的壶用久了是不是也会有水垢，与这里石灰岩形成的道理是一样的。

课后题目：通过DNA分析检测泉水中找到的微生物，有什么样的发现，你知道吗？听力答案

参考答案："faults" 断层。在最后一段中"What we’ve found in springs like this by doing the DNA analysis is that the microbes that are coming up these faults are much more like what we find at mid-ocean ridges than like the rivers and streams we could expect in the continental setting."在泉水中找到的微生物通过DNA的分析检测出断层，这与我们所预想的大陆地面上的河流以及湖泊中的微生物不一样，但却更靠近海洋中央山脊上的微生物。参考译文

位于美国的真正大峡谷，横跨16万平方英里。地质学家们迫切的期盼能够找出原因，为什么这个巨型裂谷很可能会影响未来落基山脉的形状。

他们首先来到了位于新墨西哥州阿尔伯克基北部的圣易西铎。该地区主要是明亮的黄色多孔岩石地质学里面叫做石灰岩。奇怪的是，这种岩石在水中形成。

这里的水有一些不寻常的特点，可以使这儿的岩石或石灰岩沉淀下来。道理有些像咱们家用茶壶里积存的水锈。

石灰岩是由方解石组成，与水垢的成分一样。这类型岩石的增长速度非常迅速。还有些岩石每月增大几英尺呢。

大约一公升的水将能够析出或沉淀出一小堆方解石，大小如一片阿司匹林那样大。

在烧开水的水壶中出现水垢，同样那在热温泉边上就会有石灰岩。 经测量证实，石灰岩周边的水温大约是77度。 除了能形成石灰岩以外，这里的热水蕴藏着更多的秘密。

Laura Crossey 和Karl Karlstrom总认为这些热水是由地球的内热引起的，热气通过岩石中的缝隙往上冒。慢慢地它们像裂谷一样也有了裂缝。 Laura和Karl爬到地面以下25英尺处，希望能发现新的线索。采集到水里的微生物。在显微镜下看是这些微生物。 他们中大部分是单细胞生物。科学家在实验室中分析了他们的基因，发现了令人值得关注的事情。

在泉水中找到的微生物通过DNA的分析检测出断层，这与我们所预想的大陆地面上的河流以及湖泊中的微生物不一样，但却更靠近海洋中央山脊上的微生物。重点讲解

注释：① eager adj. 渴望的；热切的；热心的
例句：
1. I'm eager to meet Anna. But tomorrow's schedule is full. Can I take a rain check ?
我真的很想认识安娜，可是我明天已经排满了事情，可不可改天再去？
2. She was eager to meet people and see places I'd talked about, but it wasn't easy for her.
她非常渴望见见我跟她说过的人，看看我提到过的地方，但这对她而言并不容易。
3. ' Everyone in Sichuan is very eager to make progress towards the government targets, ' he says.
四川的每个人都非常迫切地想作出成效以实现政府的目标，他说。

② hunch n. 预感；大块；肉峰
vt. 耸肩；预感到；弯腰驼背
vi. 隆起；向前移动
[ 第三人称单数hunches 过去式hunched 过去分词hunched 现在分词hunching ]
词组：
have a hunch that [口语]总感到，总怀疑
例句：
1. Humm… You can guess with a bit hunch.
还可以凴感觉猜一猜。
2. I have a hunch that it will snow soon.
我有快要下雪的预感。
3. Ensure that you don't hunch over when you walk.
务必保证你走路时不要驼背。
4. As soon as I arrived I knew the hunch was right.
我一到就知道我们猜想得不错。
5. As a little girl, don't hunch your back, or you look so ugly!
小姑娘家家的，绝对不能佝背啊，否则难看死了！
6. But my hunch is [that] in the endgame people will be pragmatic.
但我的预感是，在最后阶段人们会变得更务实。

③ drop out 退出；退学；脱离
例句：
1. So I decided to drop out and trust that it would all work out OK.
所以，我决议退学，并且坚信日后会证明我这样做是对的。
2. We won't drop out of the occupation, will we, after the war is over.
战争结束以后，我们不会从这个占领地退出吧？
3. Frustration against this kind of thing leads kids to drop out and run wild.
面对这类工作所产生的挫折感使孩子抛却（学习），处处乱跑。
4. We should help those who drop out of university because of economic reasons .
我们应该帮助那些由于经济原因从大学退学的学生。
5. Over half of black males in the inner cities drop out of school without graduating.
城市贫民区有超出半数的男性黑人毕业前离校；

句子讲解：

1. Geologists are eager to investigate how this giant rifting valley could affect the future of the Rockies.

【结构简析】在这里的"eager"用的很传神，把地质家们急迫想找到答案的那种心情淋漓尽致写出来，文章中没有用hope或者wish等普通的词。再有就是"could"这个词用的就很精准，把文章的体裁把握的很好。平常写作时，可以仔细地酝酿文章，尽量写地道些的文章。

【参考译文】地质学家们迫切的期盼能够找出原因，为什么这个巨型裂谷很可能会影响未来落基山脉的形状。

　　2. "What we’ve found in springs like this by doing the DNA analysis is that the microbes that are coming up these faults are much more like what we find at mid-ocean ridges （海洋中间的山脊）than like the rivers and streams we could expect in the continental setting."

【结构简析】 这个长句子，我们可以看到从句套从句，不过主要还是由句首what引导的主语从句，在加上much more...than 的句型。第一个that是系表结构，第二个是定语从句，修饰"microbes"。之后的what是引导的是宾语从句。

【参考译文】在泉水中找到的微生物通过DNA的分析检测出断层，这与我们所预想的大陆地面上的河流以及湖泊中的微生物不一样，但却更靠近海洋中央山脊上的微生物。