U–Pb zircon constraints on obduction initiation of the Unst Ophiolite: an oceanic core complex in the Scottish Caledonides?
Q. G. Crowley
R. A. Strachan
10.6084/m9.figshare.3453911.v1
https://geolsoc.figshare.com/articles/dataset/U_Pb_zircon_constraints_on_obduction_initiation_of_the_Unst_Ophiolite_an_oceanic_core_complex_in_the_Scottish_Caledonides_/3453911
<p>The Unst Ophiolite is the best exposed of a chain of early Ordovician ophiolites in the Scottish Caledonides and is widely
regarded as having formed in a supra-subduction zone setting within the Iapetus Ocean. Reinterpretation of sheeted dykes suggests
that it formed as an oceanic core complex, presumably during subduction roll-back immediately prior to obduction onto the
Laurentian margin. A new U–Pb zircon age of 484 ± 4 Ma for development of the metamorphic sole places a lower limit on the
timing of obduction, which was subsequently followed by regional-scale crustal thickening and Barrovian metamorphism during
the Grampian orogenic event.
</p>
2016-06-21 11:45:47
Scottish Caledonides
oceanic core
Grampian orogenic event
Unst Ophiolite
obduction
zircon
Geology