纪录片《地球劫难日》 第19期 石英晶体（在线收听）

Greg Retallack was one of those involved in the search.

Greg Retallack是其中一位搜寻者。

He concentrated his efforts in Antarctica.

他的工作重点是在南极洲。

There was definitely a missing piece to this whole thing,

整件事中的确有一片空白，

and we struggled with, to find out what that was and the clue was in front of us actually for quite some time.

我们致力于找出它的真相，很多时候线索就摆在我们眼前。

In the middle 1990s, he led an expedition to see what was there.

上世纪90年代中期，他带领一支探险队前往考察。

It was really the trip of a lifetime and it was something I'd wanted to do for about 15 years before.

这是一生中最难忘的一次旅行，也是我15年前最想做的事。

The team spent weeks exploring the Permian rocks,

队员们一连几周都在考察二叠纪岩层，

but one bed of rock in particular attracted his attention.

尤其是有一个岩床引起了他的注意。

We knew it was the very latest Permian bed,

它是二叠纪末期的岩床，

and inside that bed there were quartz grains that had some very unusual features.

岩床中的石英颗粒具有很不寻常的特征。

Quartz is the most common crystal on earth.

石英是地球上最常见的晶体。

It's most frequently white and translucent.

通常是白色半透明的。

Most of the quartz is just like this grain that I'm on now and it's a very clear grain.

大部分石英就像我手头上这些颗粒一样，是非常纯净的颗粒。

Looking through the microscope, the light shines through it brightly, it looks white.

在显微镜下显得亮闪闪的，纯白无比。

But some of these crystals weren't white or clear.

但是有些石英晶体既不白也不透明。