In situ pyrite sulfur isotope and trace element analyses of the world-class Dachang gold deposit, northern Qinghai-Tibetan Plateau: Implications for metallogenesis

•Dachang is a world-class gold deposit in the northern Qinghai-Tibetan Plateau.•Pre-ore and ore pyrites have similar δ34S values and trace element associations.•Au originated from pyrite in host strata, and the ultimate source was seawater.•Global temperature change led to a high level of Au in the Early Triassic source bed.•Metamorphism of pre-ore pyrite released Au, As and other metals to form the deposit.