I don't know how far you are in this game, but if you explore all area in Brocken Valley sure you find all 4 parchements wink

The hyperlink to the map is a good map for give you an idea, but isn't clearly enough, BUT I think you can search in that good Guide and maybe find a description about these side-quest!?
But: the Guide is also a thing that is full of spoilers!!! So maybe it is sadly to read to much in the Guide before play D II at least 1 time on your own, but that your onw choise smile.

Success! wink

On 7th of february 2015 : I start a new adventure in the Divinity world of Original Sin,
it's a Fantastic Freaking Fabulous Funny ... it's my All Time Favorite One !