Definition of Oligocene in English:



  • 1Relating to or denoting the third epoch of the Tertiary period, between the Eocene and Miocene epochs.

    • ‘In profiles though the summit, Qum Kuh can be considered as a pile of recumbent fold nappes of gneissose and mylonitic Oligocene and Miocene salts that have extruded from depth and gravity spread over recent gravels.’
    • ‘The Maghrebian belt, forming the main part of Sicily, consists of Permian to Oligocene shelf and basinal carbonate successions, followed by younger terrigenous deposits.’
    • ‘The global cooling trend that began in the Oligocene epoch and accelerated in the Miocene and Pliocene was catastrophic for the crocodiles.’
    • ‘This observation suggests that this relief was initiated before the Paleocene to Oligocene Pyrenean compression, certainly during the early spreading phase.’
    • ‘The fossil record of this family extends to the late Eocene or early Oligocene.’
    • ‘The bulk of the sediments on the outer margin are of Eocene to Oligocene age with thin units of younger sediments on top.’
    • ‘The Miocene saw the continuation of bioregional provinces in some instances, and great mammal migrations in other cases, as animals that had evolved on different continents during the Eocene and Oligocene spread via land-bridges.’
    • ‘In the Sahara, aridity was initially established in the late Cretaceous in the northwestern Sahara and in the main Sahara during the Oligocene, as revealed by the presence of aeolian sand in Oligocene ocean cores off NW Africa.’
    • ‘In the North Pacific, most invaders during the late Eocene to early Oligocene spread from west to east, from East Asia to the west coast of North America.’
    • ‘Comparable deformation in the Canadian Arctic began in the Late Cretaceous and continued into Oligocene time.’
    • ‘It includes the Palaeocene, Eocene, and Oligocene epochs, spanning the time from the end of the Mesozoic to the beginning of the Neogene, i.e. from 65 Ma to 23 Ma.’
    • ‘The test reported here uses well data to find this effective stress ratio in four North Sea wells penetrating Oligocene and Miocene sequences that contain polygonal fault networks.’
    • ‘Most perissodactyl lineages went extinct in the late Eocene or Oligocene.’
    • ‘The oldest fossilized vertebrate burrows discovered are known from deposits in Wyoming and Nebraska associated with the Oligocene epoch, the period between 33.7 million and 23.8 million years ago.’
    • ‘The diversity seen during the late Oligocene and early Miocene drops, and dugongs are apparently not well represented after the middle Miocene.’
    • ‘The paucity of Oligocene and Miocene records is probably due to collecting bias and limited area of outcrop.’
    • ‘Frost and coworkers mapped late Oligocene and early Miocene reef deposits from fringing/barrier reef complexes in Chiapas and Puerto Rico and tracts of small patch reefs on carbonate platforms in Antigua and Texas.’
    • ‘Leakoff tests had been carried out in each of the four wells within either the Lower Miocene or the Oligocene interval.’
    • ‘Profiles through the summit of a small nearly axisymmetric extrusion of Oligocene and Miocene salt, and simple analogue models of it, simulate the profiles of piles of ductile nappes extruded from convergent orogens.’
    • ‘The oreodonts, sheep-like artiodactyls from the Eocene and Oligocene, were among these early artiodactyls.’
    1. 1.1The Oligocene epoch or the system of rocks deposited during it.


Mid 19th century: from oligo- ‘few’ + Greek kainos new.