Terrascope has recently manufactured thin sections from North-American Alluvial Sediments for the University of Valparaiso (USA). The sediment sequence comprises laminations of fine sands and clays. One of the block (first on the left) was already impregnated and reacted weirdly when we mounted it for thin sectioning (it was like chewing gum) but we managed to produce an acceptable quality thin section out of it. The three others went very well and produced magnificent slides where the fine laminations of clays and sands are clearly visible.