A geologic remnant
Taung Kalat is a volcanic plug, a sheer-sided landform created when magma hardens within the vent of an active volcano. This specific plug was emplaced between 680,000 and 820,000 years ago. It is a satellite feature of the much larger Mount Popa, a 1,518-meter-tall stratovolcano that looms nearby. Locals often refer to the main volcano as Taung Ma-gyi, meaning "Mother Hill," to distinguish it from the plug. The rock compositions in the Mount Popa volcanic area range from basalt to dacite.
The existence of Taung Kalat is a result of differential erosion. Over hundreds of thousands of years, the softer outer layers of the original volcano, composed of ash and pyroclastic deposits, were worn away by wind and rain. The magma that solidified inside the volcano's conduit, however, was far more resistant. This durable internal cast remains today, rising 225 meters (737 feet) from the surrounding plains. The entire volcanic complex sits atop Pliocene sandstones of the Ayerwaddy Formation. While the larger Mount Popa volcano is considered dormant, its most recent activity included a series of eruptions between 12,700 and 8,500 years ago, followed by a large-scale edifice collapse around 8,000 years ago.