Kilauea Crater Rim Drive

1. Kilauea Visitor Center
2. Sulphur Banks
3. Steam Vents and Steaming Bluff
4. Kilauea Overlook
5. Hawaiian Volcano Observatory & Jaggar Museum
6. Southwest Rift Zone
7. Halemaumau Overlook
8. Keanakakoi Overlooks
9. Puu Puai Overlook
10. Thurston Lava Tube
11. Kilauea Iki Overlook

Crater Rim Drive, Stop 2 - Sulphur Banks

Sulphur Bank is a solfatara. A caldera fault, exposed just north of the Sulphur Bank, serves as a passage way for gases that originate at deeper levels in the volcano. Moderate amounts of sulfur dioxide (SO2) and high amounts of hydrogen sulfide (H2S) are released at Sulphur Bank. In the past this area has been used as a health spa and sauna.

Crystals of native sulfur precipitate on the rocks when the gas reaches the surface. The crystals are fragile (please don't touch). Other minerals, including gypsum, opal, and earthy hematite, form by the weathering of the rock and the precipitation of gases. Gypsum and opal occur as white coatings on the rocks. Hematite is red, like the rust on a car, and stains the rocks in the foreground.