epoch : Idioms & Phrases

• (Geol.), an epoch at the beginning of the American paleozoic time, and including the oldest American rocks known to be fossiliferous. See Geology.

Webster 1913

• (Chron.), a method of computing time, from the proclamation of liberty granted to the city of Antioch, about the time of the battle of Pharsalia, B.C. 48.

Webster 1913

• (Geol.), and epoch in the American lower Silurian system, immediately succeeding the Cambrian period. The name alludes to the peculiar mixture of calcareous and siliceous characteristics in many of the beds. See the Diagram under Grology.

Webster 1913

Cha*zy" ep"och

Definitions

1. (Geol.) An epoch at the close of the Canadian period of the American Lower Silurian system; -- so named from a township in Clinton Co., New York. See the Diagram under Geology.

Webster 1913

Cin`cin*na"ti ep"och

Definitions

1. (Geol.) An epoch at the close of the American lower Silurian system. The rocks are well developed near Cincinnati, Ohio. The group includes the Hudson River and Lorraine shales of New york.

Webster 1913

• (Geol.), the glacial epoch.

Webster 1913

• (Geol.), the epoch distinguished by the existence of large pachyderms. Mantell.

Webster 1913

• noun from 58 million to 40 million years ago; presence of modern mammals
  Eocene.
  

WordNet

• adjective satellite highly significant or important especially bringing about or marking the beginning of a new development or era
  epochal.
  
  • epochal decisions made by Roosevelt and Churchill
  • an epoch-making discovery

WordNet

• (Geol.), an epoch at the begining of the Devonian age in eastern America, so named from the characteristic gritty sandstone marked with impressions of cauda galli. See the Diagram under Geology.

Webster 1913

Gen`e*see" ep"och

Definitions

1. (Geol.) The closing subdivision of the Hamilton period in the American Devonian system; -- so called because the formations of this period crop out in Genesee, New York.

Webster 1913

• (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.

Webster 1913

• noun any period of time during which glaciers covered a large part of the earth's surface
  glacial period; ice age.
  
  • the most recent ice age was during the Pleistocene
• noun from two million to 11 thousand years ago; extensive glaciation of the northern hemisphere; the time of human evolution
  Pleistocene; Glacial epoch.
  

WordNet

• noun approximately the last 10,000 years
  Holocene epoch; Recent; Holocene.
  

WordNet

• the epoch of the commencement of the Julian calendar, or 46 b. c.

Webster 1913

Me*di"na ep"och

Etymology

From Medina in New York.

Definitions

1. (Geol.) A subdivision of the Niagara period in the American upper Silurian, characterized by the formations known as the Oneida conglomerate, and the Medina sandstone. See the Chart of Geology.

Webster 1913

• noun from 25 million to 13 million years ago; appearance of grazing mammals
  Miocene.
  

WordNet

• noun from 40 million to 25 million years ago; appearance of sabertoothed cats
  Oligocene.
  

WordNet

• noun from 63 million to 58 million years ago; appearance of birds and earliest mammals
  Paleocene.
  

WordNet

• noun from two million to 11 thousand years ago; extensive glaciation of the northern hemisphere; the time of human evolution
  Pleistocene; Glacial epoch.
  

WordNet

• noun from 13 million to 2 million years ago; growth of mountains; cooling of climate; more and larger mammals
  Pliocene.
  

WordNet

• noun approximately the last 10,000 years
  Holocene epoch; Recent; Holocene.
  

WordNet

• . (Geol.) See Drift epoch, under Drift, a.

Webster 1913