The Pirate Code, Icebergs
If an iceberg moves and touches any other object, it stops moving immediately. Unless that object was an island, the iceberg may be moved again at a later time per the standard rules
I take this to mean that an iceberg would stop moving if it came into contact with another piece of terrain, it wouldn’t move over or through that terrain?
That is correct. Terrain can’t overlap, so the iceberg stops as soon as it hits.