rootless cone

Rootless cones can also be formed in lava when it flows over wet sediments.

Rootless cones are named because they have no direct magma supply from the interior of the earth but they are instead fed by a lava flow.

Pseudocraters are also known as rootless cones, since they are characterised by the absence of any magma conduit which connects below the surface of the earth.

Features that resemble terrestrial rootless cones occur in Elysium, Amazonis, and Isidis and Chryse Planitiae.

Lava flowing over water-saturated ground can cause the water to erupt violently in an explosion of steam (see phreatic eruption), producing small volcano-like landforms called pseudocraters, or rootless cones.