| has gloss | eng: A pit crater (also called a subsidence crater) is a depression formed by a sinking of the ground surface lying above a void or empty chamber, rather than by the eruption of a volcano or lava vent. It is often found in chains or troughs, which may merge into a linear alignment and usually lack an elevated rim. They also lack ejected deposits and the lava flows that are associated with impact craters. Rather, they can be formed by a lava explosion from a bottled up volcano, the explosion leaving a shallow caldera, or the ceiling over a void may not be solid enough to prevent the collapse of the overlying material. A pit crater also could result from the collapse of lava tubes, dike swarms, or from collapsed magma chambers under loose material. |
