He says he has got evidence of three glaciationswith intervening glacial deposits!
The actual duration of the various glaciations probably did not vary in so great a ratio as did the intervals from one glaciation to another.
If this had happened often enough to cause all the glaciations known to geologists, the planetary orbits would be strongly elliptical instead of almost circular.
In the other glaciations the evidence is not yet clear.
Since the Indian and the African glaciations of Proterozoic times are as yet undated, we cannot be sure that they are not of the same date as the others.
This would require that the chief source of warmth be the interior of the earth, a condition which the Proterozoic, Permian, and other widespread glaciations seem to disprove.
In view of the fact that rocks of Paleozoic age cover much smaller areas than do those of later age, the three Paleozoic glaciations seem to indicate a relative frequency of glaciation.
The monumental researches of Penck and Bruckner in the Alps have there established four glaciations with mild interglacial periods, but all of these cannot be clearly traced in Britain.
Although highly probable, it cannot yet be regarded as conclusively demonstrated that the Pleistocene glaciations of Europe and of North America were exactly contemporaneous.
The record of the three early glaciations is not fully written in the animal and plant life, but it appears to be found in the river channels.
Rhine above Basle there are six, corresponding, it is believed, with the materials brought down by the four great glaciations and with the river levels of Postglacial times.
Yet even in those comparatively early days, some succession of glaciationswas suspected.
The remaining authors agree in ascribing all the glaciations to the Pleistocene period.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "glaciations" in a variety of sentences. We hope that you will now be able to make sentences using this word.
