It's in the new dungeon. Dunno which door leads to them but if you see two question marks at the bottom of the map almost next to each other then you found them
Yes it's in one of those rooms. I've been told that a room with glafire deposits is only view able if you have 15 perception. I have 20 perception so that's probably why it was so easy for me. If you still can't find any I recommend leveling up ur perception or editing ur character with saveeditonline to find the room with the deposits