Relative and chronometric dating ukran dating
Stratigraphic dating assumes that the lower layers in any particular profile are older than the upper layers in that profile ( "the law of superposition" ) and that an object cannot be older than the materials of which it is composed.
Igneous masses are dated according to whether they caused metamorphism in the surrounding rock (proof of emplacement in preexisting rock) or whether sediments were deposited on them after they were formed.
In geology, a master stratigraphic sequence for a particular region is built up by correlating the strata from different locations with one another.
As new locations are investigated, the geologist attempts to fit the new profiles into the master sequence of geological strata for that region.
The principle of stratigraphic dating is used to establish the relative age of these floral and fossil assemblages.Relative Dating Before the 20th cent., archaeologists and geologists were largely limited to the use of relative dating techniques.Estimates of the absolute age of prehistoric and geological events and remains amounted to little more than inspired guesswork, as there was no scientific basis for testing such proposals.In relative dating, the temporal order of a sequence of events is determined, allowing the investigator to surmise whether a particular object or event is older or younger than, or occurred before or after, another object or event.In absolute or chronometric dating, the investigator establishes the age of an object or event in calendar years.
Search for relative and chronometric dating:
Fossils are useful because certain assemblages of species are characteristic of specific geological eras.