It has been dated, using " uranium-lead" geochronology dating techniques.

用“铀铅”代学技术测定了它的代。

So this is a little trick I learned, oh god, in the '80s.

所以这是我上世纪80代学到的一个小技巧。

A new technique called diffusion chronometry is providing answers.

一种名为扩代学的新技术正在提供解答。

Yeah, this guy's either an amateur or he studied psychology in the eighties.

这家伙要么是业余爱好者 要么80代学过心理学。

VALERIE TROUET: I'm professor of dendrochronology at the University of Arizona.

瓦莱丽·特鲁埃特：我是那大学的树木代学教授。

With diffusion chronometry, researchers can collect crystal in rocks in different eruptions and use them to learn about the personalities of these silent volcanoes.

通过扩代学技术，研究人员能够收集不同火山喷发中的岩石晶体，并用它们来了解这些沉默火山各自的特性。