In addition, because they are trapped at high pressures many melt inclusions also provide important information about the contents of volatile elements such as H 2 O, CO 2S and Cl that drive explosive volcanic eruptions. On a larger scale, even between continents, fossil evidence can help in correlating rock layers. Absolute dating Amino acid racemisation Archaeomagnetic dating Dendrochronology Ice core Incremental dating Lichenometry Paleomagnetism Radiometric dating Radiocarbon Uranium—lead Potassium—argon Tephrochronology Luminescence dating Thermoluminescence dating. Information such as index fossils or radiometric dates can be used to correlate a particular paleomagnetic reversal to a known reversal in the GPTS. Craters are very useful in relative dating; as a general rule, the younger a planetary surface is, the fewer craters it has.
Fossil species that are used to distinguish one layer from another are called index fossils.
Concepts Deep time Geological history of Earth Geological time units. The age of the fossil must be determined so it can be compared to other fossil species from the same time period. This was done years before absolute dating methods were available. Determining the number of years that have elapsed since an event occurred or the specific time when that event occurred atomic mass: There are a number of different types of intrusions, including stocks, laccolithsbatholithssills and dikes. Lead Editor: Thus, the principle of faunal succession makes it possible to determine the relative age of unknown fossils and correlate fossil sites across large discontinuous areas.