It is that of a cold climate, accompanied by glaciation and boulder deposits.

The development of glaciation was in strict accordance with existing conditions.

The second glaciation was by far the greatest both in Europe and America.

It evidently belongs to the valley or to a later stage of glaciation.

We have considered the Laurentian highland and the glaciation which centered there.

But since destruction by glaciation no way has been opened for their return.

Most of their results are the reverse of those which brought on glaciation.

During the Archeozoic, no evidence of glaciation has yet been discovered.

Yet glaciation is now far less extensive than in the Pleistocene.

Within the field of glaciation, so far as the ice rested bodily on the surface, the rocks were rapidly worn away.