posted on Aug, 29 2012 @ 06:00 PM
Originally posted by votan
where do people get the dates from?? what is it based on?? how did the determine 9000 yrs old.
Dates in the archeological record can be established in a number of ways. Here are a handful of the most common:
1. Radiometric Dating: Radioactive materials in rocks decay at a fixed rate of time pursuant to the equation D = D0 + N(t) (eλt − 1). There are
several different processes to perform this sort of dating depending upon which type of rock is being tested...but the overall governing equation is
2. Radiocarbon Dating: Essentially the same principle however this test works only with organic materials containing carbon. However...sometimes a
stone tool or arrowhead will be found that has organic material on it which can be dated. This is really common around camp sites where stone points
might have been used to skewer meat for cooking over a fire. The soot, ash, and grease from the meat can be used as a means to cross-check the
inorganic radiometric dating.
3. Context of discovery: By far THE MOST important thing in any archeological site is the CONTEXT of where the artifact was discovered. For
example, if someone showed you a bunch of pottery from an unknown civilization that depicted snakes on them...it tells you really nothing more than
this civilization had vases with snakes on them. However, if they were discovered when excavating around what appears to be an altar...then we might
surmise that this civilization believed snakes to have divine powers or some such thing. This is part of the reason why burial sites are basically
gold mines. They provide ample organic material to corroborate the radiometric dating, as well as usually tell us something about the religious
beliefs of the people being buried.
4. Style of the Tool: Believe it or not...not all stone tools are created equally or in the same fashion. If an artifact is found completely OUT of
it's context but it shows a process of manufacture that clearly identifies it as belonging to the Clovis or Mousterian cultures then we can begin to
at least have a crude ballpark estimate as to where and when these tools were made and used.
5. Geologic Sediments: The earth is built in layers upon layers of geologic sediments. If we find tools in a layer that was deposited 50,000 years
ago...then we already have a good indication of roughly when this tool was made. The trained eye can also easily discern whether or not the artifact
was naturally deposited in a 50,000 yr strata or whether or not someone dug a hole 40,000 years ago and buried the artifact. The soil will have any
number of indications of not being deposited naturally directly above the artifact to the 40,000 yr strata...and which time it resumes it's normal
Of course...the geologic sediment method wouldn't necessarily apply here, given that erosion appears to be playing a role. However, depending upon
the specific pattern of erosion on the site itself...there still might be data which can be gleaned. Ideally, the archeologist will have multiple
vectors of analysis like this that all agree with one another in order to date an object with a high degree of certainty.