Gate Seal

level 4 - abjuration

Casting Time: 1 minute

Range: 60 feet

Components: V, S, M (a broken portal key, which the spell consumes)

Duration: 24 hours

Description not available (not OGL).
But here is a summary:

You close portals in a 30-ft cube. Gate and plane shift spells fail within it.

Sorcerer

Warlock

Wizard

Settings (Planescape)