East america fossil dating
The most important tools for paleontologists are collections of fossils and paleontological reports (with fossil plates for identification) from other locations in the region or around the world.
Micropaleontologists and palynologists work with microscopes or scanning electron microscopes (SEM).
The Sr geochronology method involves extracting these isotopes from fossil shell material (only several milligrams of sample are necessary for X-ray fluorescence spectroscopy).
The ratio of these two isotopes derived from a sample is compared with a database of known samples to determine relative ages.
Paleontology is limited to the study of sedimentary deposits where fossils are preserved, but can be used in establish relative ages of nearby igneous intrusion, faults, and other geologic features.
With the cumulative experience of centuries of paleontological research, the chronology of many fossil species are well established in context of both geologic time and distribution.
Paleontologists frequently work in conjunction with other scientists utilizing any number of other geochronology methods.
Geologic research and mapping requires the determinations of the ages and composition of rocks.
A relative age of the original shell can be established by comparing the strontium isotope ratio of the shell material to published data for the time periods where this method is usable.