The Geology 273 (Advanced Mineral Deposits) class conducted fieldwork in the Baguio-Mankayan mineral district last May 25-28, 2023. The team was led by Dr. Jillian Aira Gabo-Ratio. Mr. Leo Subang, a minerals industry expert and consultant from the Lepanto Consolidated Mining Co, also accompanied the field team. The fieldwork was participated by geology graduate students enrolled in the class. The trip was made possible by the generosity of Crescent Mining and Development Corporation and the Lepanto Consolidated Mining Co.
The activity began with a visit to the Mines View Park where Mr. Subang discussed the district geology overview and highlighted the hydrothermal alteration and mineralization in the Baguio district. This was followed by a short visit to the Nugget Hill porphyry prospect along the Philex-Baguio road, where overprinting of porphyry and epithermal veining were observed. After which, the students traveled to the Lepanto Consolidated Mining Co. in Mankayan, Benguet, which hosts the world-class Lepanto Enargite, Victoria, and Teresa deposit. In the evening, Mr. Subang gave lectures about the magmatic-hydrothermal history of the Lepanto deposits to the class, together with the exploration geologists of the company.
Mr. Subang discusses the geology of the Baguio district with students (left). Students observe the rock exposures in the Lepanto Consolidated Mining Co. in Mankayan, Benguet (right).
On the second day, the group visited the distal portion of the enargite orebody, as well as the Spanish tunnels which is the type locality of the mineral luzonite. The Buaki porphyry adjacent to the Lepanto enargite orebody was also visited where porphyry quartz stockwork veins are highlighted. The students were also able to look at the drill cores of the Far South East porphyry deposit at the Lepanto core shed. Mr. Carlo Jones Ascaño, a senior geologist from Crescent Mining and Development Corporation led the discussion on the discovery and plans for the Guinaoang Project. Drill cores from the deposit were also observed. The class’ last stop was a diatreme breccia deposit wherein the incorporated clasts are believed to have porphyry/epithermal mineralization.
The class visited several mineralized outcrops in the area.