of, denoting, or formed in the fourth epoch of the Tertiary period, between the Oligocene and Pliocene epochs, which lasted for 19 million years
Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.
the lower subdivision of Neocene rock strata, corresponding to the first, more ancient, half of the Neocene period of the earth’s geological history. In full cross sections Miocene layers are bounded by the Oligocene from below and the Pliocene from above. The Miocene was identified by C. Lyell in 1833.
The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
A geologic epoch of the Tertiary period, extending from the end of the Oligocene to the beginning of the Pliocene.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.