Preglacial
The Century Dictionary and Cyclopedia
In
geology
, prior to the glacial or boulder-drift period.
the GNU version of the Collaborative International Dictionary of English
adjective.
Prior to the glacial or drift period.
Wiktionary, Creative Commons Attribution/Share-Alike License
adjective.
Before an
ice age
(usually referring to the
Pliocene
)
Word Usage
"The Mad River Interlobate Area ecoregion is flanked by end moraines and received concentrated outwash deposits that filled preglacial valleys."