Definition of Miocene in US English:



  • 1Relating to or denoting the fourth epoch of the Tertiary period, between the Oligocene and Pliocene epochs.

    The Miocene epoch lasted from 23.3 million to 5.2 million years ago. During this time, the Alps and Himalayas were being formed and there was diversification of the primates, including the first apes

    • ‘It is evident that the southward progradation of the Indus Delta and initial development of the Indus submarine fan started by at least end Oligocene/beginning Miocene times.’
    • ‘This was a Paleogene collisional orogen, which underwent rapid and substantial extension in late Oligocene to early Miocene time, resulting in the subsidence of much of the region below sea level.’
    • ‘Apatite fission-track analyses indicate latest Oligocene to earliest Miocene ages, and are likely to reflect the same exhumational event that controls the cooling ages of the metamorphic rocks below.’
    • ‘In Japan, decapods associated with coral reef deposits were described in Miocene and Pliocene and Pleistocene rocks.’
    • ‘An Oligocene and early Miocene marine succession with a maximum aggregate thickness of 300 m accumulated on top of the erosion surface.’
    1. 1.1as noun the Miocene The Miocene epoch or the system of rocks deposited during it.


Mid 19th century: formed irregularly from Greek meiōn ‘less’ + kainos ‘new’.