An interesting find. On the opposite side of the mass to the gold pieces the coins on the surface are very different. Over most of the exposed surface the coins are cemented together by the hard green copper corrosion that has built up on their surfaces. This makes them one hard mass of corroded metal. In this new area however the coins are still corroded but are much less tightly bonded together. There is a fine organic material between them. It's black and fibrous, like peat. What's interesting about this material is that it's only between the coins and not in any of the surrounding earth. This means that the material is the remains of something buried at the same time a the coins themselves. We don't know what it is yet but I'd guess it's the remains of bags or baskets that the coins were carried in. We'll do micoscopic analysis later and hope to get a better idea.