Definition of Torridonian in English:



  • 1Relating to or denoting the later stage of the Proterozoic aeon in north-western Scotland, from about 1100 to 600 million years ago.

    • ‘The Torridonian succession can be subdivided into three groups, which are, in ascending stratigraphic order, Stoer, Sleat and Torridon.’
    • ‘Higher up the quartzite and Torridonian sandstone ridges, crags and tops offer all the challenge Snyder could ask for and at the very heart of this Letterewe wilderness lies the remotest Munro of them all - A'Mhaighdean, 3,012 ft / 918m.’
    • ‘This tectonism resulted in tilting of the Torridonian prior to deposition of the overlying Cambrian sequence to produce the classic ‘Double Unconformity’ of the Assynt region.’
    • ‘Consistent with the inference of an influx of significant amounts of fluid to flux the melting, oxygen stable isotope ratios, delta 18 O, of the Torridonian arkose (whole-rock samples) are lowered within about 400 m of the contact.’
    • ‘Much of the Torridonian arkose collected as part of this study formed the walls of the Central Layered Suite.’
    • ‘Petrographic analysis of partially melted arkose in nearby Kinloch Glen produced a pressure estimate of 150 bar and it is likely that the pressure of metamorphism of the Torridonian samples outside the Main Ring Fault was similar.’
    • ‘Efforts to determine a profile of peak temperature across the aureole of the Layered Suite were confined to the Torridonian rocks outside the Main Ring Fault.’
    • ‘Bodies of Lewisian basement gneiss, believed to represent remnants of the magma chamber roof, are found only within the Main Ring Fault, either in faulted contact with, or overlain unconformably by, the Torridonian rocks.’
    1. 1.1as noun the Torridonian The Torridonian period, or the system of rocks deposited during it.


Late 19th century: from the name of Loch Torridon, in NW Scotland, + -ian.