Forms of dating rocks
The basis for assuming that like fossils indicate contemporary formation is faunal succession.
However, as previously noted, times of volcanism and metamorphism, which are both critical parts of global processes, cannot be correlated by fossil content.
Geologic studies of active tectonism are greatly aided by definition and time calibration of local stratigraphic sequences.
Because all dating techniques may be subject to considerable error, reliability should be assessed by stratigraphic consistency between results of different dating methods or of the same method.
The work of geologists is to tell the true story of Earth's history—more precisely, a story of Earth's history that is ever more true.
A hundred years ago, we had little idea of the story's length—we had no good yardstick for time.
Correlating two separated outcrops means establishing that they share certain characteristics indicative of contemporary formation.
About 26 dating techniques can be applied to dating deposits and deformation of late Cenozoic age (past few million years).organisms, geologists employ a variety of techniques.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.Presumably if all the world’s outcrops were integrated, sediments representing all of geologic time would be available for examination.This optimistic hope, however, must be tempered by the realization that much of the record—older than 541 million years—is missing.