Petrologic studies of diamond core from the Ntina prospect/deposit, northeast Mindanao, Philippines define a diorite porphyry-related magmatic hydrothermal system or systems, and related copper, molybdenum and gold mineralisation over a minimum vertical interval of 1900 metres. Within this vertical interval, unambiguous modification of the porphyry-related magmatic hydrothermal protore in relation to structurally controlled, low-sulphidation, epithermal style alteration overprinting, occurs to a depth of 700 metres.