Abstract
The ultramafic‐mafic complex in the Marlborough terrane of the northern New England Fold Belt is dominated by members of a Neoproterozoic (ca 560 Ma) ophiolite (V1). The ophiolite has been intruded by the products of three Palaeozoic tectonomagmatic episodes (V2, V3 and V4). The V2 magmatic episode is represented by tholeiitic and calc‐alkaline basalts and gabbros of island‐arc affinities. Sm/Nd isotopes give a whole‐rock isochron age of 380 ± 19 Ma (2σ) to this episode, some 180 million years younger than the V1 ophiolitic rocks. The V3 magmatic episode includes tholeiitic and alkali basalts with enriched geochemical signatures characteristic of intraplate volcanism. A whole‐rock Sm/Nd isochron age of 293 ± 35 Ma is obtained for this event. A fourth magmatic event (V4) is represented by basaltic andesites and siliceous intrusives with geochemical features similar to modern adakites. This event has its type locality in the Percy Isles. These data provide tectonic and geochronological constraints for the previously enigmatic Marlborough terrane and as such contribute to the ever‐evolving understanding of New England Fold Belt development.
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 callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
