Absolute and relative fossil dating

Local relationships on a single outcrop or archaeological site can often be interpreted to deduce the sequence in which the materials were assembled.This then can be used to deduce the sequence of events and processes that took place or the history of that brief period of time as recorded in the .Although with clever detective work many complex time sequences or relative ages can be deduced, the ability to show that objects at two separated sites were formed at the same time requires additional information.A coin, vessel, or other common artifact could link two archaeological sites, but the possibility of recycling would have to be considered.In a way this field, called geochronology, is some of the purest detective work earth scientists do.There are two basic approaches: relative age dating, and absolute age dating.

The most useful indication of time equivalence is similar fossil content, provided of course that such remains are present.Since relative dating can easily be verified by superposition (the younger bed over the older one), intrusion (the intrusive being younger than the intrusive rock), and use of index fossils (younger fossils in a rock layer make that layer younger than another containing older fossils), relative dating can be confirmed right at the field using one's direct observation.It could also be immediately confirmed in the base office once maps and cross sections are updated and the rock units confirmed.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.