Rock such as basalt and thorium is radioactive.

像玄武岩和钍岩石具有射性。

The heat is a leftover from  Earth's formation and from from the decay of radioactive elements like thorium and uranium  that shower the crust with a constant wave of radioactivity.

热量是地球形成时遗留下来，以及钍和铀等射性元素衰变产，些射性元素不断向地壳释出持续射性波。

The ages of these flowstones can be determined by the ratio within them of the radioactive elements uranium and thorium.

些流石年龄可以通过射性元素铀和钍比例来确定。

In 2011, just before an earthquake struck the east coast of Japan, nearby researchers recorded surprisingly high concentrations of the radioactive isotope pair: radon and thoron.

2011年，就在地震袭击日本东海岸之际，附近研究人员侦测到了高浓度射性同位素组：氡和钍，对此他们十分震惊。