Abstract
THE Scourie dyke swarm intrudes the Lewisian Complex in north-west Scotland. The structural state of these basic dykes is used to subdivide the Lewisian into the pre-dyke ‘Scourian’ and post-dyke ‘Laxfordian’ complexes1. The ∼2,700 Myr (refs 2–4) pyroxene-granulite facies Scourian gneisses of the Assynt area contain undeformed NW-trending dykes. Gneisses and dykes, which underwent the ∼1,900 Myr (refs 5, 6) Laxfordian event, are now deformed and metamorphosed at amphibolite facies. Previous K–Ar measurements for the Scourie dykes in the Assynt area of the Lewisian gave a minimum age for dyke injection of 2,200 Myr (ref. 7). Younger K–Ar ages were thought to reflect later Laxfordian overprinting. I report here a Rb–Sr whole-rock isochron age of 2,390±20 Myr (2σ) and an initial 87Sr/86Sr ratio of 0.7022±0.0001 (2σ) for the Scourie dykes.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
