Originally a world inhabited by the Ancients, the name Proclarush translates to "lost in fire" -- meaning the planet likely received this moniker after it was overrun by volcanic activity. Proclarush was home to the Ancient city Taonas, part of which SG-1 discovered when the Ancient library downloaded into Jack O'Neill's brain led them there to recover a Zero Point Module.
The Taonas outpost was shielded by a dome -- likely created when lava flowed and hardened over an energy shield that has since failed -- until SG-1 destroyed it with the transport rings in order to gain access to the abandoned base.
In addition to the fully-functional Zero Point Module recovered by SG-1, the planet contained an Ancient star map.
HOME TO - Unknown
FIRST APPEARED - Lost City, Part 2
Lost City, Part 2 - SG-1 travels to Proclarush in a Tel'tak, guided by O'Neill's Ancient-influenced brain.
The Pegasus Project - Disguised as a Lantean hologram, Morgan Le Fay speaks of the history of Proclarush Taonas and its evacuation.