Cave · Fault · Lava · Mountain · Quake · Stratum

A Mountain is crust standing up. Lava is stone that has forgotten how to be solid. A Fault is the plane along which that crust fails. A Quake is the failure becoming an event. A Cave is an absence the interior has already spent. Stratum is the archive of beds the surface keeps after fire and failure have moved on.

Crust is those six as one problem: pressure stored, heat from below, and time laid in layers. Stone and Pressure take the split. Fire and Heat are the interior. The map keeps the particular geology, not a fifth element called Earth.