| Term: | Ice age |
| Definition: | A cold period in Earth history when large ice sheets extend from the polar regions into temperate latitudes. The term is sometimes used synonymously with "glacial period" or "glacial period", or embraces several such periods to define a major phase of cold climate in Earth's climatic history. |
| Term: | Ice age |
| Definition: | A major interval of geologic time during which extensive ice sheets (continental glaciers) formed over many parts of the world. The best known ice ages are 1) the Huronian in Canada, occurring very early in the Proterozoic era (2700-1800 million years ago); 2) the pre-Cambrian and early Cambrian, which occurred in the early Paleozoic era (about 540 million years ago) and left traces widely scattered over the world; and 3) the Permo-Carboniferous, occurring during the late Paleozoic era (from 290 million years ago), which was extensively developed on Gondwana, a large continent comprising what is now India, South America, Australia, Antarctica, Africa, and portions of Asia and North America. The term ice age is also applied to advances and retreats of glaciers during the Quaternary era. |
| Term: | Ice age |
| Definition: | Particular period of a geological era during which extensive ice sheets (continental glaciers) covered many parts of the world. |
| Term: | Ice age |
| Definition: | An ice age or glacial period is characterized by a long-term reduction in the temperature of the Earth's climate, resulting in growth of ice sheets and glaciers. |
| Term: | Ice age |
| Definition: | Particular period of a geological era during which extensive ice sheets (continental glaciers) covered many parts of the world. |
| Term: | Ice age |
| Definition: | Period of time when glaciers dominate the landscape of the Earth. The last major Ice Age was during the Pleistocene epoch. |