【英语时差8,16】关于雷尼尔峰（上）

（单词翻译）

 On our last program, we introduced a mysterious geological feature that can be found on the slopes of Mount Rainier, a volcano in Washington state. Flows of hardened lava¹ cling to the tops of ridges² as they wind down the mountainside, ignoring deep valleys to either side. Why Didn’t The lava Flow Down The Valleys, As Any Other Liquid Would? The key to this is the epoch³ in which these features formed. They formed during an ice age, which means that this curious geography is the result of a tremendous, elemental battle between fire and ice–a battle which ice won. Imagine a volcano, besieged⁴ by glaciers⁵. The glacial ice is thickest where it’s filling deep valleys on the mountainside, and thinnest where there are ridges that almost poke⁶ their rocky spines⁷ up through the ice sheet.