Dalradian
/dalˈrɑːdɪən
/adjective Geology
1Relating to or denoting a series of late Precambrian metamorphic rocks, occurring in Scotland and Ireland.Kennedy and McKerrow observed that the Late Precambrian / Cambrian Dalradian sequences of the Scottish Highlands were deformed in the Ordovician....
- Thus, movement along the Mannin Thrust brought mid-crustal plutons and Dalradian country rocks tectonically above the extrusive volcanic sequence.
- Peak metamorphic temperatures in the Dalradian schists reached 620 30°C in the north but only c.400°C in the south.
1.1 (as noun the Dalradian) The Dalradian series of rocks.Here, the first Grampian deformation to affect the Dalradian can be matched with very low-grade rocks in the adjacent Clew Bay Complex, a dismembered accretionary complex....
- The age signature of detrital zircons within the Dalradian as well as the Torridonian and Moine is consistent with derivation from a Laurentian hinterland.
- Current controversy over the maximum age of the Dalradian arises from contrasting interpretations of structural and lithostratigraphical relationships, and differing geological interpretation of chronological data.
Origin
Late 19th century: from Dalrad-, from Dalriada (by alteration), + -ian.