Granite and Time

The Teton Range rose from the earth’s crust along a fault line nine million years ago. But the granite itself is far older — Precambrian gneiss dating back 2.7 billion years.

Time is visible in granite. Lichen grows on its surface at roughly one centimeter per century. Pine bark splits and furrows over decades. Mountain ridgelines erode imperceptibly over millennia. These are the slowest patterns on earth.