ARCHEAN PERIOD to PLEISTOCENE PERIOD: 3.5 billion years ago to 10,000 years ago
Stromatolites are a VITAL aspect of any fossil collection or museum exhibit. They represent THE oldest traces of life on our planet. Stromatolites are accretionary deposits made by tiny cyanobacteria organisms. They can be found alive today and like today, they thrived in shallow waters in prehistory. The stromatolite accretions are formed by the cyanobacteria trapping, binding and precipitating minerals and sediment. In most cases, the stromatolite is a fossilized build-up of layers of accretions produced by the cyanobacteria. In rare cases, the mineral-rich water infuses the stromatolite and petrifies the actual bacteria as well as the layers of accretions, preserving the cyanobacteria in a life-life manner, in stone. The fossil record demonstrates a vast geographical diversity of the occurrence of prehistoric stromatolites on Earth.