Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Holocene (approximately the last 10 thousand years [ka] before present), Late Pleistocene (10 to 126 ka), Middle Pleistocene (126 to 750 ka) and Early Pleistocene (older than 750 ka). Four different ratings are shown: A*/A=high-quality ages and B/C=low-quality ages.
