Definition of Proterozoic in English:



  • 1Relating to or denoting the aeon that constitutes the later part of the Precambrian, between the Archaean aeon and the Cambrian period, in which the earliest forms of life evolved.

    • ‘No rock standard has been identified formally as marking the base; at the top of the Proterozoic the Cambrian - Precambrian boundary is identified on the basis of fossils.’
    • ‘The key to understanding the early evolution of eukaryotes lies in the Proterozoic fossil record, especially microfossils.’
    • ‘Archean and most Proterozoic sedimentary rocks are notable for their distinct lack of any bioturbated textures.’
    • ‘This is the general name for all Archaean and Proterozoic basement gneisses of the NW Scotland mainland and Outer Hebrides.’
    • ‘The bulk of the Mozambique belt of eastern Africa and Madacascar is underlain by deeply eroded and multiply deformed high-grade Proterozoic and Archaean rocks.’
    1. 1.1as noun the Proterozoic The Proterozoic aeon or the system of rocks deposited during it.


Late 19th century: from Greek proteros ‘former’ + zōē ‘life’, zōos ‘living’ + -ic.