And so Earth, as we approach this greatest of the deaths, was the same: all but lifeless, the rocks eroding away.

Through time the soft rocks weather away or erode by the action of streams.

In Earth Science we learned that rocks erode by edges and corners wearing down first.

The softer rock erodes more quickly than overlying hard rock.

The softer overlying rock has since eroded away, leaving a distinct rugged shape.

Some rocks (usually softer ones) erode more rapidly than others.

The rock can erode into caves, but it takes many thousands of years as water drips through it.

When rocks erode over time, their pieces are picked up by wind, water or ice (as in glaciers).

These rocks further erode to form a circular bay with a narrow entrance called a cove.

Over many thousands of years, the older sedimentary rock eroded and left the harder igneous formation.