In the cases of many aquifers, research is lacking or disputed as to the age of the water and the behavior of the water inside the aquifer.Large, prolific aquifers (notably the Nubian Sandstone Aquifer System and the Ogallala Aquifer) containing fossil water are of significant socio-economic value.Ammoniten („Ammonshörner“) gehören zu den bekanntesten und populärsten Fossilien.Hier ein Vertreter der Spezies Perisphinctes wartae aus dem Oberjura des Innersteberglandes (südliches Niedersachsen).Fossil water or paleowater is an ancient body of water that has been contained in some undisturbed space, typically groundwater in an aquifer, for millennia.Other types of fossil water can include subglacial lakes, such as Antarctica's Lake Vostok, and even ancient water on other planets.The study of fossils across geological time, how they were formed, and the evolutionary relationships between taxa (phylogeny) are some of the most important functions of the science of paleontology.Such a preserved specimen is called a "fossil" if it is older than some minimum age, most often the arbitrary date of 10,000 years.
Carbon-14 has a half-life of about 5730 years, and therefore it is used to date biological samples up to about 60,000 years in the past.
Beyond that timespan, the amount of the original C formed by irradiation of nitrogen by neutrons from the spontaneous fission of uranium, present in trace quantities almost everywhere.
For these samples, other dating methods must be used.
Furthermore, if a sample has been contaminated, scientists will know about it.
Ironically, given how supposedly useless carbon dating is claimed to be, Creation Ministries International rests part of their "101 Evidences" on carbon dating being a useful method for within several thousand years.