Exploration indication of hidden gold deposits using the fine-grained soil prospecting method and its nano-micron metal migration evidence in the alluvial soil covered area, Jiaodong

Jiaodong stands out among three global provinces boasting gold reserves surpassing 5000 tons. As geological exploration in the region continues to rise, the significance of deep and covered areas in Jiaodong for ore prospecting becomes increasingly evident. In this study, a Fine-grained soil prospecting method was employed in the Qujia hidden gold deposit and its surrounding region, situated in Yantai City, Shandong Province, and concealed by alluvial soil. The gold (Au) content exhibited a high enrichment level, and the range of Au and silver (Ag) geochemical anomalies demonstrated a robust correlation with known hidden orebodies. Furthermore, transmission electron microscopy and nano-CT were utilized to identify nano-micron metal particles and micro-fractures in the wall rock. A hereditary relationship between the nano-micron metal particles of ore-forming elements present in surface media and the deep orebody was observed. A migration model detailing the movement of deep ore-forming materials in the form of nano-micron metal particles, governed by a multi-agent relay dominated by ascending geogas flow, was established in the Qujia gold deposit in Jiaodong. These findings contribute theoretical support for the fine-grained soil prospecting method in geochemical exploration within alluvial soil covered areas. •The fine-grained soil prospecting method was employed in the Qujia gold deposit.•The surface geochemical anomalies corresponded to known ore bodies.•The nano-micron metal particles and micro-fractures were identified.•The migration model was established.