Four Craters Lava Field Four Craters Lava Field Four Craters Lava Field is a basaltic volcanic field located south east of Newberry Caldera in the U.S. state of Oregon. The volcanic field covers about 30 square kilometers. Four Pleistocene cinder cones are the source of the flows in the field and are aligned along a fissure trending N 30° W. The cones rise 75 to 120 meters above the flows and the distance between the northern most and southern most cones is about 3.5 kilometers. Closely related to the Four Craters lava field is Crack-in-the-Ground located at the southwest corner of the field. The
Lava of lava dome eruptions include the Novarupta dome, and successive lava domes of Mount St Helens. Lava tubes are formed when a flow of relatively fluid lava cools on the upper surface sufficiently to form a crust. Beneath this crust, which being made of rock is an excellent insulator, the lava can continue to flow as a liquid. When this flow occurs over a prolonged period of time the lava conduit can form a tunnel-like aperture or "lava tube", which can conduct molten rock many kilometres from the vent without cooling appreciably. Often these lava tubes drain out once the