Lithospheric architecture and metallogenesis in liaodong peninsula, north china craton: Insights from zircon hf-nd isotope mapping

Abstract

The Liaodong Peninsula is an important mineral province in northern China. Elucidating its lithospheric architecture and structural evolution is important for gold metallogenic research and exploration in the region. In this study, Hf-Nd isotope maps from magmatic rocks are constructed and compared to geological maps to correlate isotopic signatures with geological features. It is found that gold deposits of different age periods in Liaodong are located in areas with specific εHf(t) and εNd ranges (Triassic: from ‒8 to ‒4 and from ‒12 to ‒8, Jurassic: from ‒22 to ‒8 and from ‒14 to ‒8, Cretaceous: from ‒12 to ‒10 and from ‒22 to ‒20), respectively. This may reflect that when the Paleo-Pacific plate was subducted beneath the North China Craton, the magma was derived from the juvenile lower crust and the ancient lower crust, and formed the low-to-moderate hydrothermal Au-(Ag) and Pb-Zn deposits in the Triassic. In the Jurassic, continued subduction may have led to lithospheric thickening. Subsequently, the magma from the ancient lower crust upwelled and formed low-to-moderate hydrothermal Au deposits and porphyry Mo deposits. In the Cretaceous, crustal delamination may have taken place. The magma from the ancient lower crust upwelled and formed various low-to-moderate hydrothermal Au deposits.