Samples of the unearthed corals and fossils were brought to the town hall of Magpet for viewing and were scheduled to be transported to Manila for further studies.
Town mayor Efren Piñol Sr. theorized that Mahongcog could have been part of a large body of water, although he said experts should have the final say.
North Cotabato is a landlocked province.
The local government has already asked experts from the University of the Philippines in Diliman, Quezon City to come to Magpet to identify the artifacts.
Piñol said the team from UP is expected to visit Magpet for a thorough study in the area sometime in April.
Entry to the discovery site is now restricted to prevent the artifacts from being stolen.
Aside from Magpet, similar things were also discovered in the town of Mlang, also in North Cotabato, and in Baguio City in 2002. (Williamor A. Magbanua/MindaNews contributor)