Fossil dating technology
When significant oxygen entered the atmosphere, ancient life multiplied.But after a few hundred million years, Earth's oxygen plummeted, resulting in a die-off likely greater than the extinction of ...Similarly, in geologic studies, vast quantities of information from widely spaced outcrops have to be integrated.Some method of correlating rock units must be found.Episodes of global volcanic activity, rifting of continents, folding, and metamorphism are defined by absolute ages.The results suggest that the present-day global tectonic scheme was operative in the distant past as well.
Very similar contents have been found in more than 150-million-year-old ... Some 18 million years ago, a tiny monkey weighing little more than a baseball lived in the Amazon rainforest, the smallest fossil monkey known worldwide.
Just as the use of the fossil record has allowed a precise definition of geologic processes in approximately the past 600 million years, absolute ages allow correlations back to Earth’s oldest known rocks formed more than 4 billion years ago.
In fact, even in younger rocks, absolute dating is the only way that the fossil record can be calibrated.
Similarly, in geology, if distinctive granitic pebbles can be found in the sediment beside a similar granitic body, it can be inferred that the granite, after cooling, had been uplifted and eroded and therefore was not injected into the adjacent rock sequence.
Although with clever detective work many complex time sequences or relative ages can be deduced, the ability to show that objects at two separated sites were formed at the same time requires additional information.These include some that establish a relative chronology in which occurrences can be placed in the correct sequence relative to one another or to some known succession of events.