英语听力：自然百科 澳大利亚大堡礁 Great Barrier Reef—12

 All lava¹ has a chemical signature that tells scientists where it came from and when it was erupting.” 

 

The higher up the old volcano, the more pristine² the rocks will be. They are the last remaining evidence of the eruption³ which created this volcano more than 23 million years ago. Only these rocks can reveal the full picture. 

 

Five hundred feet up, and Will's finally got the sample.

 

“Now I got to figure out a way to get down.” 

 

Analysis of the rocks from the Glasshouse Mountains and Mount Warning reveals something amazing. The lava in these two mountains, 100 miles apart, comes from the same place. How? 

 

The answer lies in an incredibly rare geological phenomenon. Deep below Australia, in the Earth’s molten interior is a hot spot, a mysterious area of liquid rock. It's hot enough to punch fresh lava all the way to the surface. But there is something very special about hot spots, something that allows them to reveal the story of Australia's past. Because hot spots don't move, but continents do, sliding right over. 

 

This chain of mountains is a record of that movement. Tens of millions of years old, it proves that Australia has been moving northeast all the way from Antarctica, and about five inches every year and that makes it the fastest-moving continent on the planet. 

 

Fifty million years ago, Australia was near the South Pole. Cold water and the darkest of winters, conditions no coral could survive, but then it began to move north.

1 lava   

n.熔岩，火山岩

参考例句：

• The lava flowed down the sides of the volcano.熔岩沿火山坡面涌流而下。
• His anger spilled out like lava.他的愤怒像火山爆发似的迸发出来。

2 pristine   

adj.原来的，古时的，原始的，纯净的，无垢的

参考例句：

• He wiped his fingers on his pristine handkerchief.他用他那块洁净的手帕擦手指。
• He wasn't about to blemish that pristine record.他本不想去玷污那清白的过去。

3 eruption   

n.火山爆发；（战争等）爆发；（疾病等）发作

参考例句：

• The temple was destroyed in the violent eruption of 1470 BC.庙宇在公元前1470年猛烈的火山爆发中摧毁了。
• The eruption of a volcano is spontaneous.火山的爆发是自发的。