This text systematically investigates the Laotudingzi monzogranite (a gold-hosting intrusion) and the Dongbaligou gold ore deposit in the Laoling gold ore belt through comprehensive geochronological, whole-rock geochemical (macroelement and microelement), strontium-neodymium-lead-hafnium isotopic and in situ sulfur-lead isotopic analysis of pyrite, combined with hydrogen-oxygen isotopic studies of hydrothermal quartz. The results demonstrate a significant Early–Middle Jurassic magmatic-mineralization event in southern Jilin Province (Ji’nan). The gold mine is structurally controlled by detachment fractures within the Laoling metamorphic core complex, which developed in an extended environment. The metallogenic materials are primarily derived from adakitic magma, supporting a “decratonic-type” genetic model. By integrating geochronological, geochemical, and isotopic datasets from the ore-related intrusions and gold deposits, as well as fluid inclusion characteristics, we elucidate the metallogenic mechanism linking Jurassic gold mineralization to subduction-related cratonic destruction. The process involved lower crustal thickening induced by Paleo-Pacific Plate subduction, lithospheric destabilization via gravitational foundering and delamination, and syn-extensional magmatism that sourced ore-forming fluids during cratonic lithosphere thinning. This work establishes a genetic framework connecting plate subduction, lithospheric removal, and gold endowment in convergent margin settings.

Seamount basalts undergoing long-term seawater immersion and percolation are subject to varying degrees of low-temperature alteration, causing a release of substantial amounts of Sr-Nd-Pb-Hf into seawater and thereby providing a sustained, long-term, mantle-derived source for marine material cycling. Such a mantle input mixes with crustal weathering material settled to the ocean via rivers and aeolian dust, resulting in crust-mantle mixing, altogether constraining the Sr-Nd-Pb-Hf isotopic compositions of seawater and polymetallic crusts. Among these, the isotopic compositions of Sr and Pb more closely resemble those of terrigenous input materials, while Nd isotopes indicate a roughly averaged mixing mechanism. The Hf isotopic composition approaches that of enriched mantle-derived Ocean Island Basalts (OIBs). Low-temperature-altered minerals in basalt, such as montmorillonite and phillipsite, possess both permanently negative and variable charges. This causes the formation of an electrostatic field, resulting in an adsorptive potential that facilitates the initial growth of charged Fe and Mn colloidal particles on the surfaces of altered basalt. Simultaneously, Fe, Mn, Co, Ni, and Rare-Earth Elements (REEs) released during the low-temperature alteration process contribute essential material for the growth of a polymetallic crust.