Any experts on Cretaceous fossils from Ignaberga in Sweden out there that can help me? At that time, around 80 Ma it was a archipelago-like enviroment, rich on belemnites, brachiopods and shark) Ive got two small remains that I want to know what they could be.

I found a very unusual rock last fall that I have some trouble identifying. Since this being Sweden the damn glaciers of the Ice age transport rocks all over the place (or at least from the north to the south). So the provenance of the stone is basically unkown except that it must be something possible for Sweden and neighbouring countries. I have never seen anything like it here in Sweden but perhaps some of my english speaking readers out there have at least a qualified guess to offer me. It doesnt look like any sedimentary rock that Ive seen anywhere in Sweden before. I have my guess of course, but I want your oppinion on it.

As you can se from the images its some sort of sedimentary rock. It basically looks like some form of clay (or silt) stone with stripes of quarts sand in it and rich in Iron (but that could of course be something it was exposed to simply). I havent actually weighed it, but it feels quite heavy, perhaps because of the iron?. The larger granule/grain in the middle is also quartz as far as I can tell.

Update: Added two more closeups.