冰川纪
冰川时期

[ noun ]
any period of time during which glaciers covered a large part of the earth's surface
<noun.time>
the most recent ice age was during the Pleistocene

Glacial \Gla"cial\, a. [L. glacialis, from glacies ice: cf. F.
glacial.]
1. Pertaining to ice or to its action; consisting of ice;
frozen; icy; esp., pertaining to glaciers; as, glacial
phenomena. --Lyell.

2. (Chem.) Resembling ice; having the appearance and
consistency of ice; -- said of certain solid compounds;
as, glacial phosphoric or acetic acids.

{Glacial acid} (Chem.), an acid of such strength or purity as
to crystallize at an ordinary temperature, in an icelike
form; as acetic or carbolic acid.

{Glacial drift} (Geol.), earth and rocks which have been
transported by moving ice, land ice, or icebergs; bowlder
drift.

{Glacial epoch} or {Glacial period} (Geol.), a period during
which the climate of the modern temperate regions was
polar, and ice covered large portions of the northern
hemisphere to the mountain tops.

{Glacial theory} or {Glacial hypothesis}. (Geol.) See
{Glacier theory}, under {Glacier}.