Characteristics

Lumachelle is a sedimentary rock that consist of a large amount of whole or broken fossils which are brought together due to sedimentation. Lumachelles are different from reefs due to the fact that reefs are formed by animals which are sedimented in their living position. Lumachelles have two possible origins. The first corresponds to an accumulation in areas of high biological productivity (delta, estuaries, lagoons, mineralized springs) where certain communities of species can then build large reefs (bioconstruction). When organisms die, their shells or shells break down and accumulate. The second possibility is to stop the sedimentation. The shells and shells always fall at the same rate to the bottom of the water, but as the clays no longer settle, they form a layer.

References

• https://fr.wikipedia.org/wiki/Lumachelle