Geological analysis of the Kematu epithermal deposit reveals its origins and offers key insights for future resource development

16 Jul 2026

The Kematu epithermal gold deposit in Tboli, Mindanao, contains significant gold and silver reserves. The Tboli gold rush began in the late 1980s and reached its peak during the 1990s, with the first systematic exploration of the Kematu deposit conducted between 1994 and 1996.

The research investigates how the deposit formed by analyzing the minerals, rock compositions, and sulfur isotopes present in the area. It finds that gold and silver are hosted in three distinct mineralization stages, primarily in quartz- and sulfide-rich veins within volcanic rocks. The study also determines that the sulfur in the deposit originated from magma, confirming that the deposit formed from hot, mineral-rich fluids rising from deep underground during volcanic activity.

The findings are important for both scientific and economic reasons. Understanding the mineralization process helps in identifying new gold deposits in the region, supporting future exploration and mining efforts. It aids in the exploration for new ore bodies and/or adjacent epithermal deposits in the area. With an estimated 3.8 million tons of ore containing high concentrations of gold and silver, the deposit represents a valuable resource.

Moreover, the findings improve the geological understanding of the Parker Volcanic Complex. Linking the Kematu deposit to the Parker Volcanic Complex enhances broader geological understanding of how gold deposits form in volcanic regions. This research not only contributes to the field of geology but also provides practical insights for mining and resource development in the Philippines.

Authors: Alan Royce B. Tizon (National Institute of Geological Sciences, College of Science, University of the Philippines Diliman | Department of Science and Technology, Philippine Science High School –Southern Mindanao Campus, Davao City), Jillian Aira S. Gabo-Ratio (National Institute of Geological Sciences, College of Science, University of the Philippines Diliman), Pearlyn Manalo (Graduate School of International Resource Sciences, Akita University), Ryohei Takahashi (Graduate School of International Resource Sciences, Akita University), Ma. Yna Rose D. Garcia (National Institute of Geological Sciences, College of Science, University of the Philippines Diliman) and Juan Alex Vianne D. Amoroso (Apex Mining Company Incorporated, Pasig City)

Read the full paper: https://onlinelibrary.wiley.com/doi/epdf/10.1111/rge.12339

Photo: Parker Volcano, or Mount Melibengoy, seen here from the E, is located at the S end of Mindanao Island in the Philippines. Photo by Chris Newall.

Geological analysis of the Kematu epithermal deposit reveals its origins and offers key insights for future resource development

The Kematu epithermal gold deposit in Tboli, Mindanao, contains significant gold and silver reserves. The Tboli gold rush began in the late 1980s and reached its peak during the 1990s, with the first systematic exploration of the Kematu deposit conducted between 1994 and 1996.

The research investigates how the deposit formed by analyzing the minerals, rock compositions, and sulfur isotopes present in the area. It finds that gold and silver are hosted in three distinct mineralization stages, primarily in quartz- and sulfide-rich veins within volcanic rocks. The study also determines that the sulfur in the deposit originated from magma, confirming that the deposit formed from hot, mineral-rich fluids rising from deep underground during volcanic activity.

The findings are important for both scientific and economic reasons. Understanding the mineralization process helps in identifying new gold deposits in the region, supporting future exploration and mining efforts. It aids in the exploration for new ore bodies and/or adjacent epithermal deposits in the area. With an estimated 3.8 million tons of ore containing high concentrations of gold and silver, the deposit represents a valuable resource.

Moreover, the findings improve the geological understanding of the Parker Volcanic Complex. Linking the Kematu deposit to the Parker Volcanic Complex enhances broader geological understanding of how gold deposits form in volcanic regions. This research not only contributes to the field of geology but also provides practical insights for mining and resource development in the Philippines.

Authors: Alan Royce B. Tizon (National Institute of Geological Sciences, College of Science, University of the Philippines Diliman | Department of Science and Technology, Philippine Science High School –Southern Mindanao Campus, Davao City), Jillian Aira S. Gabo-Ratio (National Institute of Geological Sciences, College of Science, University of the Philippines Diliman), Pearlyn Manalo (Graduate School of International Resource Sciences, Akita University), Ryohei Takahashi (Graduate School of International Resource Sciences, Akita University), Ma. Yna Rose D. Garcia (National Institute of Geological Sciences, College of Science, University of the Philippines Diliman) and Juan Alex Vianne D. Amoroso (Apex Mining Company Incorporated, Pasig City)

Read the full paper: https://onlinelibrary.wiley.com/doi/epdf/10.1111/rge.12339

Photo: Parker Volcano, or Mount Melibengoy, seen here from the E, is located at the S end of Mindanao Island in the Philippines. Photo by Chris Newall.