Fossils are the remains of plants and animals that have been preserved in rocks. Geologists have found fossils that are only a few thousand years old and others that are more than million years old. Fossils are rare; it takes very specific conditions for an organism to be preserved as a fossil. Scientists use two different methods for determining the age of a fossil: absolute dating and relative dating. In , Henry Becquerel discovered in the laboratory that uranium undergoes radioactive decay. Lord Rutherford, who developed a model of the atom, determined that the radioactive decay of uranium can be used to measure the geologic age of rocks.
Acritarch - Wikipedia
This diagram shows a selection of rock layers, also known as stratigraphic columns, from Koobi Fora. Lake Turkana has a geologic history that helped keep fossils intact. Scientists suggest that the lake as it appears today has only been around for about , years. The current environment around Lake Turkana is very dry. Over the course of time, though, the area has seen many changes. The sediment eventually settles on the bottom of a lake bed or at the mouth of a river, where it accumulates.
Last Updated: July 1, References. This article was co-authored by our trained team of editors and researchers who validated it for accuracy and comprehensiveness. This article has been viewed 7, times. Learn more Dating fossils is an interesting and enlightening process.
Mary Anning The 19th-century British fossil collector Mary Anning proved you don't have to be a paleontologist to contribute to science. Anning was one of the first people to collect, display, and correctly identify the fossils of ichthyosaurs, plesiosaurs, and pterosaurs. Her contributions to the understanding of Jurassic life were so impressive that in , Anning was named among the ten British women who have most influenced the history of science.