Final answer:
The Belt Supergroup formed along a passive margin, which is associated with continental rifting. One example of a passive margin is the Moroccan coastline.
Step-by-step explanation:
The Belt Supergroup formed as rifting produced fault controlled basins where shallow marine condition persisted along a passive margin. These passive margins are associated with continental rifting and occur when a continental mass splits apart. One example of a passive margin is the Moroccan coastline, which was tectonically active in the past.