Referent answer points 1. porphyry type of ore deposits and their formation conditions; 2. epithermal ore deposits and their formation conditions; 3. skarn type of ore deposits and their formation conditionsReferent answer points: 1. porphyry type of ore deposits and their formation conditions; 2. epithermal ore deposits and their formation conditions; 3. skarn type of ore deposits and their formation conditions 1 km