Glinka (crater)

Glinka is a pit-floored crater on Mercury, which was discovered in 1974 by Mariner 10 spacecraft. Its floor is covered by the smooth plain material and displays a kidney-shaped collapse feature, which is also called a central pit. The size of the pit, which was first noticed in MESSENGER images obtained in January 2008, is 20 × 8.5 km. It is surrounded by a bright pyroclastic deposit. Such a feature may have resulted from collapse of a magma chamber underlying the central part of the crater. The collapse feature is an analog of Earth's volcanic calderas.