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知道了早期落基山脈下降的原因，會帶給我們怎么樣的啟示？落基山脈經過了侵蝕后，接下來的火山作用又帶給了這座山什么樣的變化呢？經歷了侵蝕和火山作用，落基山脈還會經歷什么呢？值得期待！
This fine-grained ash suggests huge volcanic eruptions nearby. They spewed out（噴射） thick clouds of hot air, ash and volcanic rock which settled on the ground. Radiocarbon（ [核] 放射性碳）dating the rock revealed that it happened 25 million years ago.
"Ash was deposited as it came out of the sky as plumes（羽毛）. Most of it came from the West and was deposited in the basins across Wyoming."
After the lower Rockies were buried by their own rock, volcanic ash settled on top and covered the area with a thick white sheet.
"At the time of the deepest basin filled with this volcanic material, all you would see in this area was the very tops of the peaks exposed, the rest would be large extensive lateral ash sheets."
Erosion and volcanism（n. [地質] 火山作用） completely transformed the terrain and buried the Rockies. But then, over millions of years, rivers flushed out the eroded rock.
Most of it is thought to have ended up in the Missouri and Mississippi Rivers, from where it was transported into the sea. What's left are the mountains we see today. This also confirmed the theory geologists had about the formation of Wind River Canyon, the incredible amount of infield （耕地）buried the Owl Creek Mountains. Wind River flowed on top and began carving into the mountains, creating the canyon we see today.
The investigation into what happened to the early Rocky Mountains reveals two major clues. Granite, found on the Pumpkin Buttes, is evidence that the early Rockies dumped their eroded rock into the basins. Wind River Canyon, cutting straight through the Owl Creek Mountains is evidence that the Rockies were buried by their own debris. The once mighty Rockies had now been cut down to nearly half their original size, but the story was far from over. Before they became the mountains we know today, they would have to endure an even greater assault.
小編有約：早期落基山脈的變遷史讓人著迷，就如同一位滄桑的老人，它的故事給Daisy的感覺就是你不探索則以，如果開始聽了，就會堅持聽下去，然后悟出自己的道理，一切事物都有自己的衰榮史，最開始從海底升起來，到慢慢的經歷毀滅性的打擊，一直保存到我們現在看到的山，雖然高度已減少一半，但是它依然在這個世界存在著，好多人遭受到了打擊，選擇一條不歸路。當然這只是小編的意見，歡迎大家各抒己見。
課后題目：這次Daisy想要問問大家有仔細聽嗎？對于早期落基山脈歷史變遷的調查，結果揭示出了兩個主要線索。能告訴Daisy是哪兩個主要線索嗎? 可以用自己的話來表述，只要意思差不多就行哦。
