Geochronology

Geochronology, field of scientific investigation concerned with determining the 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. Earth’s surface is a complex mosaic of exposures of different rock types that are assembled in an astonishing array of geometries and sequences. Individual rocks in the myriad of rock outcroppings contain certain materials or mineralogical information.