The climatic pattern of East Asia shifted in response to cratonic thinning in the Early Cretaceous

In response to westward subduction of the Paleo-Pacific, the North China Craton experienced the uplift of an eastern coastal plateau followed by subsidence in the Early Cretaceous, which potentially drove a shift in climatic patterns. Here we use the oxygen isotope ratios of garnets from magmatic-hydrothermal ore systems to infer the origins and signatures of mineralization fluids during this tectonic transition. The garnet oxygen isotope values range from approximately –11.4 to +13.5‰, with extremely depleted oxygen isotope ratios exclusively found in the northern margin, indicating extensive involvement of meteoric and lacustrine fluid in the back-arc hinterland. This geological record aligns with climate modeling exhibiting that the coastal plateau amplified northeastward transport of moisture from tropical Tethyan Ocean. The long-distance transport strongly depleted ¹⁸O and ²H (D). As the cratonic lithosphere thinned and the plateau subsided, the Pacific influences began to dominate the climatic pattern of East Asia.