Below us dark, gullied ridges held another half million years of sediments. Beyond them was the basalt, laid down when this vast plain was swamped in lava, 5.2 million years ago.

就在我们远眺处的下方，黝黑的沟状脊代表了另外一种50万年的沉积层，更远处铺满了玄武岩，520万年前，这块巨大的平原被淹没在火山岩浆之中。