The Yinchangping deposit is situated within a complex ophiolitic mélange belt. The district is dominated by a suite of northwest-trending, light gray to greenish mid-ocean ridge basalts (MORB) and associated greenschists. This MORB assemblage is flanked to the east and west by ocean island basalts (OIB) and seamount platform carbonates. The OIB sequence strikes NE-SW and primarily comprises weakly deformed greenschists and meta-basalts. The associated seamount platform carbonates consist of limestone and marbleized limestone, characterized by relatively weak metamorphic and structural overprinting. In the western portion of the district, a strongly deformed sedimentary package is exposed, consisting of mudstone and calcsilicate mudstone interbedded with chert and limestone lenses. a total of three mineralized alteration zones have been identified in the area. The ore bodies are generally distributed in the NW-SE-trending direction, occurring in a stratoid and vein-like form in the basalt and greenschist of the ophiolitic mélange zone. Eighteen tungsten and two beryllium orebodies occur between elevations of 2100 m and 2900 m, overall trending NW–SE with dips of 54 – 68°. The tungsten orebodies range from 0.33 m to 5.79 m in thickness, averaging ∼0.26 % WO3; potential scheelite resources exceed 10,000 t. The beryllium orebodies are 0.54 – 1.66 m thick, averaging 0.17 % BeO. The Yinchangping and Mahuaping deposits constitute an Early Oligocene “magmatic-metamorphic hybrid” Be-W metallogenic continuum in the Sanjiang Tethyan belt: the proximal Yinchangping records initial mixing between deep magmatic fluids and metamorphic fluids, whereas the distal Mahuaping underwent more intensive metamorphism.

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