Torridonian
/ˌtɒrɪˈdəʊnɪən
/adjective Geology
1Relating to or denoting the later stage of the Proterozoic aeon in NW Scotland, from about 1100 to 600 million years ago.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....
- 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.
- 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 (as noun the Torridonian) The Torridonian period, or the system of rocks deposited during it.
Origin
Late 19th century: from the name of Loch Torridon, in NW Scotland, + -ian.