Tumuli in basalt flow, Iceland

tumulus

Cinder cone exposed by coastal erosion

Lake-filled explosion crater, New Zealand

hydrothermal, volcanic hazards

Sulfur chimneys and fumaroles

steam vents, sulfur mineralization, sulphur

Large block in ash flow tuff, Colorado

pyroclastic, ignimbrite, volcanic

Columnar-jointed basalt, Oregon

lava, dwshed, columns, columnar, colonnade

Pillow basalt, Olympic Mountains, Washington

Siletzia

Mt. St. Helens stratovolcano, Washington

Cascade volcanoes

Lava Flows of Columbia River Basalt Group, Washington

CRBG, columns, columnar, colonnade

Bandelier Tuff, Los Alamos, New Mexico

volcanic, ash flow tuff, welded, pyroclastic

Thurston Lava Tube, Hawaii

basaltic, volcanic

Flowing pahoehoe, Hawaii. (vertical)

Flowing pahoehoe lava flow

basalt, volcanic, igneous, hot spot

Cross-section of cinder cone, SE California.

igneous, explosive volcanic, volcanism