prior to a given
, especially the Pleistocene.
formed or occurring before a glacial period, esp before the Pleistocene epoch
Collins English Dictionary - Complete & Unabridged 10th Edition
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In some instances, buried preglacial streams provide extensive groundwater resources.
Preglacial fluvial sediments ma y underlie the glacial deposits in many of the preglacial valleys.
Broad outwash plains are located along the entire northern edge of the preglacial lakes.
Often preglacial valleys were filled with glacially derived sediment.
The preglacial physiographic provinces are divided by the type of bedrock.
They may have developed where preglacial streams had already eroded channels into the weaker parts of the bedrock.
Many islandlike remnants of preglacial soils remained after the glacial floods.