FMIPA UI Research Team's Exploration in Natuna: Uncovering Geodiversity at the Nation's Edge

A research team from the Geology Study Program, Faculty of Mathematics and Natural Sciences, Universitas Indonesia (FMIPA UI), conducted an exploration to the Natuna Islands, Riau Islands Province, to trace the geological history of Indonesia’s border region, which still holds many untold mysteries.

The exploration, which took place from July 16 to 24, 2025, covered areas from the main island of Natuna to smaller islands such as Pulau Tiga and Pulau Sedanau. A total of 35 geological observation points were successfully explored.

Led by Dr. Reza Syahputra, a lecturer and Head of the Geology Study Program at FMIPA UI, the research team—comprising three other members: Ahmad Rizky Reynda, Mochamad Ikral Pamungkas, and Arham Anugrah Bahri—conducted an exploration of the geological diversity (geodiversity) in Indonesia’s border region, which remains largely under-researched.

“Geologically, Natuna is very unique. We suspect that the subsurface of this region is a fragment of an ancient oceanic plate that has been uplifted to the surface. This finding is important for understanding the formation history of western Indonesia,” said Dr. Reza, explaining the background of his research.

The team explored various ancient rock formations along the coast and on remote islands. Several rock samples, such as gabbro and basalt, were successfully collected for laboratory analysis. The research employed a structural geology approach and the Anisotropy of Magnetic Susceptibility (AMS) method, which can reveal stress and deformation patterns in rocks based on the orientation of magnetic minerals within them.

Preliminary results indicate the presence of marine sedimentary rocks, granite over 70 million years old, and oceanic basement rocks belonging to the ophiolite group. This combination makes Natuna a strategic location for studying the tectonic dynamics and geological history of Southeast Asia.

However, the exploration did not come without challenges. Extreme weather in the Natuna waters—especially high waves and strong winds—prevented access to several observation points in the northern part of the island. The team also had to move between locations using fishing boats, which made the distribution of field equipment more difficult.

Nevertheless, most of the exploration targets were successfully reached. The data and samples brought back will be further analyzed in the Geology Laboratory of FMIPA UI.

This research is also part of a collaborative project between UI and the University of Chinese Academy of Sciences (UCAS), which previously conducted studies in Bangka Island. The findings from the Natuna exploration will be published in an international scientific journal in collaboration with researchers from both institutions.

“In the future, the results of this Natuna exploration will be published in an international scientific journal and are expected to make a significant contribution to the advancement of earth sciences,” concluded Dr. Reza.

These findings are expected to make a significant contribution to the mapping of geological potential, coastal spatial planning, and geological disaster mitigation strategies in Indonesia’s border regions.