Zircon Hf Isotope Mapping for Understanding Crustal Architecture and Its Controls on Mineralization during Early Cretaceous in the Southern Great Xing’an Range, NE China

Abstract

Voluminous Early Cretaceous granitoids and associated large-scale ore deposits are distributed within the southern Great Xing’ an Range (SGXR), NE China. Based on previously published geochronology and zircon Hf-isotope data, Hf isotope mapping is undertaken to improve our understanding of crustal architecture and its controls on ore deposits. The ore-related Early Cretaceous granitoids were sourced predominantly from juvenile crust, with the involvement of variable proportions of ancient crustal materials. The crustal architecture, as inferred from Hf isotopic contour maps, indicates two distinct Hf isotopic domains in SGXR, including (1) a higher-ε_Hf (+7 to +11) juvenile crust containing minor ancient crustal material, and (2) a lower-ε_Hf (+2 to +6) juvenile crust containing a greater proportion of ancient crustal materials. The Hf isotopic maps identify links between crustal architecture and regional metallogeny. Copper deposits and other deposits with significant Cu production are restricted mainly to the higher-ε_Hf juvenile crustal regions in the northern and eastern SGXR. Deposits dominated by other metals (e.g., Mo, Sn, W, Pb, Zn, and Ag) occur mainly in the lower- ε_Hf juvenile crustal regions in the southern and western SGXR. Interaction between juvenile crust-derived melts and ancient crustal components played an important role on the distribution of various ore metals.