Martian lava tube Martian lava tube Martian lava tubes are natural sub-surface lava tube caverns on Mars that are believed to form as a result of fast-moving, basaltic lava flows associated with shield volcanism. Lava tubes usually form when the external surface of the lava channels cools more quickly and forms a hardened crust over subsurface lava flows. The flow eventually ceases and drains out of the tube, leaving a conduit-shaped void space which is usually several meters below the surface. Lava tubes are typically associated with extremely fluid pahoehoe lava. Gravity on mars is about 38% that of Earth's, allowing Martian lava
Lava dome in the dome's conduit. Domes undergo various processes such as growth, collapse, solidification and erosion. Lava domes grow by endogenic dome growth or exogenic dome growth. The former implies the enlargement of a lava dome due to the influx of magma into the dome interior, and the latter refers to discrete lobes of lava emplaced upon the surface of the dome It is the high viscosity of the lava that prevents it from flowing far from the vent from which it extrudes, creating a dome-like shape of sticky lava that then cools slowly in-situ. Spines and lava flows are common