Definition of orogen in US English:

orogen

noun

Geology
  • A belt of the earth's crust involved in the formation of mountains.

    • ‘The Delamerian Orogen is a compressional orogen developed by westward vergent folds and thrust faults.’
    • ‘Together with the Appalachian, Caledonian and Variscan orogens, the Uralian orogeny contributed to the assembly of the late Palaeozoic supercontinent of Pangaea.’
    • ‘These collision zones are known as orogenic belts, and the mountains are referred to as orogens.’
    • ‘Several features of the mountain belt are atypical when compared with other Palaeozoic orogens such as the Appalachians, Caledonides and Variscides.’
    • ‘In the southern half of the Caledonian orogen, sedimentation in the post-Caledonian continental basins started significantly earlier, in the Mid-Devonian.’

Origin

1920s: from Greek oros ‘mountain’ + -gen.

Pronunciation

orogen

/ˈôrəˌjen/