Subduction-induced high-pressure collision metamorphism: Evidence from Early Cambrian eclogites in the HP Hutul Mélange, Zavkhan Terrane, Western Mongolia

The Zavkhan Terrane, one of the largest Precambrian microcontinents in the Central Asian Orogenic Belt, hosts a unique combination of magmatic complexes, carbonate sediments, and eclogite facies rocks. These features provide critical insights into the Rodinia supercontinent evolution, the global carbon cycle, and high-field-strength element mobilization during deep subduction. While the magmatic and sedimentary history of the terrane has been relatively well studied, the discovery of high-pressure metamorphic rocks raises new questions about its tectonic evolution. This study presents integrated petrological, geochemical, and geochronological data from metamorphic rocks (felsic schist, pelitic schist, and amphibolite) associated with the Urgamal eclogite in the Zavkhan-Khungui zone and the Khungui eclogite in the Mélange zone, both within the Zavkhan Terrane. Metasedimentary rocks associated with both eclogites were deposited at both active and passive continental margins and recorded a clockwise metamorphic P–T path. Amphibolites exhibit MORB-like geochemistry and underwent amphibolite-facies metamorphism (0.7–0.9 GPa, 395–449 °C). Zircon U–Pb ages constrain the protoliths of the Urgamal (