Dating of rocks fossils and geologic events
Earth’s surface is a complex mosaic of exposures of different rock types that are assembled in an astonishing array of geometries and sequences.
Since parent uranium atoms change into daughter atoms with time at a known rate, their relative abundance leads directly to the absolute age of the host mineral.
age and history of Earth’s rocks and rock assemblages.
Such time determinations are made and the record of past geologic events is deciphered by studying the distribution and succession of rock strata, as well as the character of the fossil organisms preserved within the strata.
When rocks are subjected to high temperatures and pressures in mountain roots formed where continents collide, certain datable minerals grow and even regrow to record the timing of such geologic events.
When these regions are later exposed in uptilted portions of ancient continents, a history of terrestrial rock-forming events can be deduced.