Tracing black shales in the source of a porphyry Mo deposit using molybdenum isotopes

Abstract Porphyry Mo deposits are important suppliers of molybdenum for industrial applications, but the origin and source metals in these remain debated. Here, we present isotope data Miocene mineralized porphyritic monzogranites (MPMs) Paleocene barren biotite tuffs (BMTs) from Bangpu porphyry (Cu) deposit Gangdese metallogenic belt. The results show that MPMs display radiogenic Sr Pb isotopes elevated δ98/95Mo (relative to NIST SRM 3134; +0.07‰–1.2‰) contents, which exceed range depleted mantle. These characteristics cannot be attributed surface weathering, hydrothermal alteration, magmatic differentiation, or partial melting rather reflect incorporation black shales into their magma sources, as evidenced by significant correlations between εNd(t) aluminum saturation index (ASI) values. In contrast, BMTs lower values than samples, no with ASI contrasting samples provide strong evidence addition played an role formation deposit. Our study thus establishes a possible link organic-rich sediments highlights great potential studying deposits.