A product of continental collision
The graphite deposits in Mohnyin Township are a direct result of the immense geological forces that created the Himalayan mountain range. These deposits are located within the Mogok Metamorphic Belt, a zone of intensely deformed and heated rocks running north-to-south through Myanmar. This belt is a region that experienced deep transformation during the collision of the Indian and Eurasian tectonic plates, an event that began between 59 and 40 million years ago.
The process started with ancient marine sediments, full of organic matter like algae and other microorganisms, that were buried and compacted over millions of years. As the Indian plate drove northward, these carbonaceous sedimentary rocks were caught in the continental collision zone. They were subjected to extreme temperatures, often exceeding 500°C, and immense pressures. This intense metamorphic environment cooked the buried organic material, driving off volatile elements like hydrogen and oxygen and progressively rearranging the remaining carbon atoms into the perfectly ordered, hexagonal sheets characteristic of crystalline graphite. The host rocks for this graphite are typically high-grade metamorphic rocks such as schists and gneisses.