Dolok Sibualbuali, Stratovolcano in North Sumatra, Indonesia.

Dolok Sibualbuali is a stratovolcano in northern Sumatra, Indonesia. It has two solfatara fields on its eastern flank and a rhyolitic-dacitic lava dome that erupted from the Toru-Asik fault.

The volcano formed through tectonic interactions between the Eurasian and Indo-Australian plates, which created the entire Bukit Barisan mountain chain. This volcanic activity has shaped the region's geology over millions of years.

The name Dolok Sibualbuali is Batak Angkola; dolok means mountain in the Batak languages. The two solfatara fields on the eastern flank are the mountain's visible geothermal feature, and the Toru-Asik fault, which produced the rhyolitic-dacitic lava dome, gives the summit area its structure.

Visitors must obtain permits from the Dolok Sibual-Buali Nature Reserve authorities and hire a local guide before attempting the climb. The mountain requires good fitness and proper equipment suitable for rough terrain and potential steam vents.

The lava dome on Sibualbuali is rhyolitic-dacitic and was erupted along the Toru-Asik fault, a structure that also shaped the dome's position on the mountain. The two solfatara fields lie on the eastern flank, while the fumaroles sit on the southern slope.