Abstract
The anorogenic igneous rocks of Mull consist essentially of a lava pile of predominantly basaltic composition, cut by an intrusive complex. The basement consists of Precambrian metamorphic rocks of the Moine Series underlain by Lewisian gneiss. The intrusive complex contains a significant proportion of granitic intrusions which can be ascribed to three successive centres of activity, Centres 1–3. We report new major and trace element, including rare earth element analyses, 87Sr/86Sr ratios and δ18O values for a comprehensive collection of granitic rocks from the 3 centres. The δ18O values range from +4 to −6 indicating variable extent of interaction between the rocks and heated meteoric groundwater. However, correlations of δ18O with other major and trace element data and 87Sr/86Sr ratios are uniformly low, apart from Fe2O3. It is thus unlikely that the interaction of the rocks with meteoric water has systematically altered the chemical (including Sr isotope) characteristics. The chemical and Sr isotope data reflect magmatic values and can therefore be used to comment on the petrogenesis of the granitic rocks.
Published Version
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