No problem, Glen. The term "fault gouge" is familiar to all who have taken a basic geology course. But it didn't seem to make sense in the context you used it in the original post, so I just took it that you meant a visible gouge in the ocean floor such as the scar, or gouge, left in a tabletop from the careless use of a carving knife. But thanks for the interesting additional information on fault rock. I hadn't heard of cataclasite, mylonite or pseudotachylite!

Michael Williams
Arroyo Grande, CA USA