The southern part of the Cretaceous Kohistan island arc is occupied by an extensive belt dominantly comprised of amphibolites. These include banded amphibolites of partly meta-volcanic parentage, and non-banded amphibolites derived from intrusive rock. In addition to being relict, banding has also been produced by shear deformation, metamorphic/metasomatic segregation and, possibly, by lit-par-lit injection of plagiogranitic material. Non-banded amphibolites also occur as retrograde products of noritic granulites forming the lopolithic Chilas complex. The chemistry of 37 rocks has been compared with those of known tectonic environments. The amphibolites have chemical characteristics similar to volcanic rocks found in island arcs and most of the analyses apparently support affinity with the calc-alkaline series. The amphibolites consist essentially of hornblende, plagioclase and/or epidote. Garnet and clinopyroxene have developed locally in rocks of appropriate bulk composition. Metamorphism may have taken place during the mid-Cretaceous under conditions of 550 to 680 ~ and 4.5 to 6.5 kbar PH2o. The metamorphic grade appears to increase from the centre of the southern belt toward the Chilas complex to the north and Indus-Zangbo suture (IZS) to the south. In the vicinity of the IZS, garnet-clinopyroxene + amphibole assemblage developed locally in response to high P-T.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2025 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.