Neoproterozoic-Early Paleozoic evolution of the southern Central Asian Orogenic Belt: constraints from eclogites in the Beishan Orogenic Belt (NW China)

Abstract

Eclogites have provided important constraints on the processes of plate subduction, collision and the overall tectonic evolution of orogens. The Gubaoquan eclogite is the only one identified in the Beishan Orogenic Belt, which constitutes the southernmost part of the Central Asian Orogenic Belt. The protolith age and tectonic setting of the eclogite and associated rock units remain ill-constrained. U–Pb dating of the eclogite indicates a Neoproterozoic age of 887 ± 7 Ma for its protolith age and an Ordovician age of 461 ± 15 Ma for the eclogite facies metamorphism. Detailed U-Pb ages of zircons, monazites, rutiles and apatites from the eclogite and country rocks suggest that they have experienced multiple metamorphic events in the Neoproterozoic and Paleozoic, which are inferred to correlate with retrograde metamorphism during the later exhumation. The protoliths of the Gubaoquan eclogite are of continental origin, and along with the extensive distribution of the Neoproterozoic arc-related rocks probably resulted from assembly of Rodinia. This work was financially supported by the National Natural Science Foundation of China (41730213 and 41890831), Hong Kong RGC GRF grants (17307918), HKU Internal Grants for Member of Chinese Academy of Sciences (102009906) and for Distinguished Research Achievement Award (102010100), Northwest University Excellent Doctoral Thesis Cultivation Program (YB2023003), and from the Australian Research Council (FL160100168).