Ice Age Floods Institute Members may have heard the term Quaternary during Chapter Presentations and Field Trips, or may have learned that the Quaternary Period represents the last 2.588 million years (~2.6 million years) of earth history, or that it is divided into the Pleistocene and Holocene Epochs.

The Quaternary began with the Pleistocene (~2.6 million years ago) and the strata and landscape features reflect the major climate changes of the last Ice Age (synonymous with the Pleistocene Epoch).

But where did the term Quaternary come from? 

The word suggests the number four as in quadrangle, quadrant, quadruplet, etc.

For its origins we need to go back a few hundred years to see how the geologic time scale in use today had its origins.

The science of geology had a very slow start only beginning to take hold in the late seventeenth and early eighteenth centuries.

Both Giovanni Arduino (1714-1795) a mining geologist studying the rock layers in northern Italy around 1759 and Jules Desnoyers working in the Seine Basin in France in 1829 divided their rock sequences into four units; Primary, Secondary, Tertiary and Quaternary.

The term Quaternary was applied by Desnoyers to the fourth more recent strata that consists of loose to poorly indurated or cemented strata.

The terms Primary and Secondary have been dropped but Tertiary and Quaternary are still used today.

These attempts to develop a regional framework of strata were based on the publication of a paper by NIcholaus Steno in 1669 where he laid out the geologic Principle of Superposition. He argued that lower strata in a tectonically undisturbed section must be older than those on top.

He also pointed out that strata tend to be deposited in a horizontal position, the law of Original Horizontality. How old these strata might be was not known, new tools would need to be developed to answer that question. However, that is another story.

Gene Kiver
June 2020