Stratiform skarn is distinct from contact metasomatic skarn in wall rock and zonation.

The protolith is intermediate-basic volcanic and pyroclastic rocks without carbonate.

No granitic outcrop coeval with skarn implies that a batholith supply fluid.

Hydrothermal fluids also supply a fraction of Ca and Fe to ensure skarn formation.

Stratiform skarns are metasomatic products of protolith by hydrothermal fluid.