Terrane boundary and spatio-temporal distribution of ore deposits in the Sanjiang Tethyan Orogen: Insights from zircon Hf-isotopic mapping

摘要

The Sanjiang Tethyan Orogen (SJTO) of the eastern Tethyan tectonic belt in China records a transition from Late Paleozoic Tethys realm to Cenozoic continental collision associated with the formation of large metallic mineral deposits. This contribution combines geological and Hf-isotopic data for igneous rocks from the SJTO, together with the salient features associated with mineralization to gain insights into the crustal architecture and metallogeny. Integrating the available information from tectonic events, sedimentary successions, paleobiogeography, and paleolatitude based on paleomagnetic data, the Hf isotopic maps that we construct highlight the Changning-Menglian Suture as an important tectonic boundary between the Gondwana and Cathaysian continents. The Changning-Menglian Suture separates two distinct Hf isotopic domains with an old, reworked, crustal block to the southwestern part of the SJTO, and a juvenile crustal block with significant mantle-derived components to the northeastern part of the orogen.