Very sorry, I cleared the naskeil mines. Ive been going through each area looking for any of the "black" and trying to uncover it all. I've just seemed to have run out of it. Except Durlugs tower. I think I'm in chapter 3?
If you cleared the Nashkel mines, then there was an end foe. If you loot him and take a letter he was carrying, you should get an idea where to look for the next level foe. You are still some way to go before you can enter BG city.
Spoiler:
The end foe in Nashkel mines is Mulahey. For the next foe: Look for Tranzig at Feldepost's Inn in Beregost.
Comments
if you have mods installed, there could be a mod interrupting the sequence so its not happening correctly
this is also based off the fact that you are in the cloakwood mines and not nashkiel mines
if you just finished the nashkiel mines and started chapter 3, then you need to find the bandit camp
unfortunately you weren't all that clear on what mines you completed
Spoiler: