glaciation

Glaciation then exposed huge deposits of frozen methane, a powerful greenhouse gas.

In England at least three periods of glaciation seem to be indicated by the glacial deposits.

There were signs of previous glaciation in the form of erratics and many examples of polishing and grooving.

Thus the angle of the lava-built slopes, and the lines of glaciation, testify to the former existence of a high central summit.

The planet's in the middle of a glaciation, the land surface down to the fiftieth parallel is iced over solid.

They are to be counted among the four chief attractions, the other three being Long's Peak, the glaciation, and the timber-line.