Topic summary
Counter slab
Extracted from the Wikipedia article Compression fossil.
Slabs
A slab and counter slab, more often called a part and counterpart in paleoentomology and paleobotany, are the matching halves of a compression fossil, a fossil-bearing matrix formed in sedimentary deposits. When excavated the matrix may be split along the natural grain or cleavage of the rock. A fossil embedded in the sediment may then also split down the middle, with fossil remains sticking to both surfaces, or the counter slab may simply show a negative impression or mould of the fossil. Comparing slab and counter slab has led to the exposure of a number of fossil forgeries.