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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 （海洋中間的山脊）than like the rivers and streams we could expect in the continental setting."
小編有約：這一期的落基山脈中出現了 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."（科學的解釋是位于山底下的地熱引起碳酸鈣析出，使之形成晶體般的石灰巖。）咱們燒開水的壺用久了是不是也會有水垢，與這里石灰巖形成的道理是一樣的。
課后題目：通過DNA分析檢測泉水中找到的微生物，有什么樣的發現，你知道嗎？
