Bioclast

Bioclasts are skeletal fossil fragments of once living marine or land organisms that are found in sedimentary rocks laid down in a marine environment—especially limestone varieties around the globe, some of which take on distinct textures and coloration from their predominant bioclasts—that geologists, archaeologists and paleontologists use to date a rock strata to a particular geological era.

In geology bioclasts are used for such things relative dating purposes can be whole fossils or broken fragments of organisms. Their preponderance can give a rough guide to life diversity in the historic biosphere, but absolute counts much depend on water conditions such as the depth of the deposition, local currents, as well as wave strength in large body of water such as lakes. They can be used to study the age of the formation environment of the rocks that bioclasts finds itself in. one of the major contributions of bioclasts is that they form in regions where organisms lived and eventually died, over time. This is important because with the right conditions (pressure and temperature) there is a high possibility for hydrocarbon potential. This is because hydrocarbons will eventually form due to the rich organic matter that has died and enriches the sediments. A vast chunk of the fossil records during the Metazoan era were all bioclasts of cloudina shells.

Cloudina

The cloudina shells make their shell beds when they are filled into depressions that occur between thrombolitic domes and occasionally form in troughs between low amplitude current ripples that occur in grainstone facies. These organisms have the best potential index fossil in the Late Ediacaran era.