Percolating into empty cracks and cavities, such as those found in breccias, it creates flowstones.

渗透到空裂缝和空腔，例如在角发现裂缝和空腔，它会产生流石。

The team now reckon the Member 4 breccia formed between 3.4m and 3.6m years ago, over a million years earlier than believed.

该团队现在估计 Member 4 角形成于 340 万至 360 万年前，人们认为早了 100 万年以上。

To test that idea, they directly dated the cave breccias in Members 2 and 4 using cosmogenic nuclide dating, which Dr Granger helped develop.

为了验证这个想法，他们使用格兰杰博士帮助开发成因核素测年法，直接对成员 2 和成员 4 洞穴角进行了测年。

Using this method Dr Granger and colleagues determined, in 2015, that the breccia in Member 2 is 3.7m years old—1.5m years more ancient than originally thought.

使用这种方法，Granger 博士及其同事在 2015 年确定，成员 2 角有 370 万年历史——最初认为要古老 150 万年。

When a breccia-forming object falls into a cave, it finds itself shielded from cosmic rays, and the steady decay of its existing cosmogenic nuclides can be used to determine how long ago it fell in.

当形成角物体落入洞穴时， 它发现自己免受射线影响， 并且其现有成因核素稳定衰变可以用来确定它落入洞穴时间。