IYAMAPO: Natural Forces Responsible for Oyo Hill Cracking, Peeling -Geologists

Geologists have said that natural forces were responsible for the recent cracking and peeling of the Iyamapo Inselberg in Igbeti, in Olorunsogo Local Government Area of Oyo State.

“It is essential to clarify that the event was not caused by tectonic activity (an earthquake). Rather, it is a geomorphic occurrence resulting from temperature-induced stress on the rock body,” the Nigerian Mining and Geosciences Society said.

The state government has also allayed the fears of the people of the town over the tremor which occurred at the weekend.

A statement, on Monday, signed by the Commissioner for Information, Dotun Oyelade, said the government had commenced an immediate evaluation of the situation and called on residents to remain calm.

According to the commissioner, experts from the Oyo State Solid Mineral Development Agency under its Director General, Mr Biodun Oni, had been dispatched to the site.

“The disruption is a result of physical weathering on the rock, caused by intense heat from February to May early this year, followed by sudden cooling.

“This expansion and contraction leads to cracking, peeling, and sheeting, resulting in minor tremors and rock movements as witnessed over the weekend,” Oyelade said.

He disclosed that the government was also working with experts from the University of Ibadan to analyse the geological activity, to provide solutions to mitigate future occurrences.

He assured residents not to panic.

“There is no cause for alarm,” the commissioner said, adding that there had been no casualty.

The commissioner urged individuals living near the rock to evacuate temporarily until a permanent solution was reached.

He restated that the government remained committed to ensuring the safety and well-being of all citizens.

“We will continue to prioritise public safety and give updates as investigations progress,” he said.

Addressing the public, the NMGS said the recent rock peeling incident at the Iyamapo inselberg in Igbeti was a natural geomorphic process and not the result of an earthquake.

In a press statement, NMGS clarified that the geological event, which occurred on Saturday, June 7, was caused by natural physical weathering.

According to the agency, “The Nigeria Mining and Geosciences Society wishes to formally address the recent geological event involving the peeling of the Iyamapo inselberg in Igbeti, Oyo State, which occurred on Saturday, June 7, 2025,” the statement read.

“We recognise the concerns expressed by the Igbeti community and neighbouring areas and reaffirm our commitment to providing scientifically grounded clarification and assurance.”

According to the statement, the peeling of the rock resulted from exfoliation and sheeting—natural geomorphic processes caused by temperature changes.

“The rock, identified as coarse-grained granite, experienced significant thermal expansion due to intense heat between February and May.

“The rapid cooling that followed created cracks and microfractures on the surface, eventually leading to the audible cracking and detachment of rock layers.

“These are common geomorphic processes in which outer rock layers detach due to thermal expansion and contraction,” NMGS explained.

It advised that houses or farmlands located at least 50 to 100 metres from the rock should be evacuated to avoid danger of future and subsequent occurrences.

It also called for a halt of further physical developments and human activity within the said distance.

“We encourage the Igbeti community and the general public to remain calm and trust in the ongoing investigative efforts.

“NMGS will continue to monitor developments and share updates as more information becomes available,” the statement read.

An environmentalist, Makolo Daniel, said, “The mountain is breathing. That’s how it was formed.”

He added, “You can’t prevent this kind of incident. They are natural occurrences. If you look around the major parts of Nigeria, you see hills, you see mountains, you see valleys. They are natural interactions of the ecosystem.

“Human beings don’t have much control over the environment except the way and manner it was built. What you saw there, is an in-depth analysis carried into it.”

Daniel also called for government support for those likely to be displaced.

“The only thing the government can do is to come to the rescue of those who are likely to be displaced by moving them from that place to another place,” he said.

He added that the planet was simply expressing itself. “This is the reaction of the ecosystem. We will have to live with it and will have to be with us until the end of the world,” he said.

Urban planner and environmentalist, Michael Simire, also weighed in, highlighting the connection between high temperatures and rock exfoliation.

“I’m aware of a phenomenon like when high heat affects the rods, it can lead to exfoliation,” he said.

“I don’t know whether there was a crack on the hill or whether that was just a movement. The movement involves a kind of quake. A quake can also lead to cracks. It can also lead to the mass of rock to crack. The heat can also lead to depletion by rocks.”

Simire emphasised that both high temperatures and physical stress can produce such effects.

“Both phenomena are possible and this could be a result of high temperature. It can also lead to the fact that we are experiencing higher temperatures. Maybe there is an issue of climate change,” he added.

On the safety of communities living close to the formation, Simire issued a clear warning.

“If it is a major separation, it might lead to total separation of parts of this rock mass. And it could be detrimental to the safety of people living around,” he said.