Since it's a spoilers thread, I'll spoil it a little bit.

I don't remember the details, but IIRC you are supposed to talk to someone outside the cave, tell them you found the barrier and they will send some men to dig through it. The barrier will be gone when you get back in the crypt.
I think the person you are supposed to talk to is right outside the crypt, but I may be mistaken - I played the game long time ago.