Geologists got rock cores from two miles down, at the active fault zone. They looked at those fault rocks with an electron microscope. And they found an incredibly thin coating of clay polish on the rocks.

地质学家们在断层带活跃区域的两英里深处采集了岩心样本，他们利用电子显微镜研究那些断层岩，发现这些岩石上覆盖着极薄的一层粘土" 抛光蜡" 。