Stromatolites dating method
Nevertheless, the original terminology to distinguish Precambrian rocks from all younger rocks is still used for subdividing within 50 degrees.Most fossil carbonates, evaporites, phosphorites, and red beds of Phanerozoic age dating back to the Cambrian have a similar bimodal distribution with respect to their paleoequators. Scientist Olivia Judson provides this good example of what happens to an adult male gorilla in the tropical rainforests of the Congo; "An adult male gorilla— all 330 pounds of him—will be reduced to a pile of bones and hair within 10 days of his death.
That's because the newly found fossil is far too complex to have developed soon after the planet's first life forms, he said.
Stromatolites or stromatoliths are defined (Riding 2007) as layered accretionary structures formed in shallow water by the trapping, binding and cementation of sedimentary grains by layers of microorganisms, especially cyanobacteria (commonly known as blue-green algae).
Stromatolites provide some of the most ancient records of life on Earth.
By the close of the Proterozoic, the abundance of stromatolites decreased markedly, though cyanobacteria continued to leave a fossil record, such as Langiella and Kidstoniella known from the Lower Devonian Rhynie chert.
The cyanobacteria have also been tremendously important in shaping the course of evolution and ecological change throughout earth's history.