datingmiltonkeynes com - Relative dating of the earth

Volcanic ash layers often have unique chemical and physical characteristics that can be used for correlation.

Great volcanic eruptions in the Western United States in the geologic past produced airfall deposits that have been recognized as far away as the East Coast.

This web page provides an overview of selected geochronology methods used by USGS scientists.

New dating methods are invented all the time, however, most have practical limitations.

More modern correlation technologies include use of marine stable isotope records, paleomagnetic dating, tephrachronology, geomorphological methods, sedimentation characteristics, and other geochemical and radiometric methods.