Spatial Association Between Orogenic Gold Mineralization and Structures Revealed by 3D Prospectivity Modeling: A Case Study of the Xiadian Gold Deposit, Jiaodong Peninsula, China

The Xiadian orogenic deposit with ~ 100 t of gold resources, located in the Jiaodong Peninsula, Eastern China, shows an economically attractive gold mineralization that is spatially associated with the Zhaoping detachment fault. This study presents a combination of field investigation, 3D modeling, spatial analysis of models, and prospectivity modeling using a multi-layer perceptron deep neural network to understand the association between gold mineralization and structural deformation and to identify targets for deep exploration. The principal gold mineralization at Xiadian occurs as disseminated ore associated with strongly fractured rocks. Spatial analysis determined that gold mineralization is located primarily in convex segments (0–50 m) of the fault footwall within 150 m of the fault buffer where the dip is gentle (~ 35° to 55°). Sulfide vein ore with high Au grades is, by contrast, typically sited within steeply dipping fracture-fill distal to the Zhaoping detachment (150–250 m), consistently in areas with NE-strike and associated with steep segments of the detachment fault. The distribution of the orebodies is attributed to brittle–ductile deformation proximal to the detachment and distal brittle extension. Given the characteristics of syn-deformation mineralization and the stress regime (NW σ 3 , NE σ 2 , and vertical σ 1 ), the NE-plunging ore shoots were interpreted as the result of auriferous fluid flow into oblique dilation zones formed by the coupled normal and dextral strike-slip movement of the Zhaoping fault. Six potential gold targets were identified sub-horizontal to, and NE-trending from, known orebodies. This study highlights the utility of 3D prospectivity modeling as a robust tool for understanding orogenic gold spatial distribution and related structural controls.