In this case the geologists drilled into the stalagmites and estimated their age from the way that uranium decays into an isotope of thorium.
地质学家在石笋上钻孔，使用铀衰变成钍的同位素的方法确定它们的年龄。
2
The measurement of the decay of radioactive isotopes, especially uranium, strontium, rubidium, argon and carbon, has allowed geologists to more precisely determine the age of rock formations.
对放射性同位素衰变的测量，尤其是铀、锶、铷、氩和碳，可允许地质学家更精确地确定岩层的年龄。
3
Due to the young age of interlayer oxidation and unsatisfied uranium sources, uranium metallogenic prospect of this area need more research and exploration.