quaternary

The youngest geologic period; includes the present time;
The latest period of time in the stratigraphic column, 0 – 2 million years, represented by local accumulations of Pleistocene and Holocene deposits which continue, without change of fauna, from the top of the Pliocene (Tertiary). The Quaternary appears to be an artificial division of time to separate pre-human from post-human sedimentation. As thus defined, the Quaternary is increasing in duration as man’s ancestry becomes longer.

Geological Glossary