Dating a cave system in the Yucatan

19 May 2014

At www.eurekalert.org/pub_releases/2014-05/ps-dad_1051214.php ... this short piece discloses how a skeleton found in a cave, now 130 feet below sea level, was dated to the Late Pleistocene period. The sea level rise curve was used in order to get back to the desired period, a curve that is based on an assumption sea level rise was a constant process over many thousands of years (following the end of the Ice Age and the melting of a huge ice sheet). Even sea level graphs show a number of jerks when sea levels jumped markedly (or conversely, fell) which should imply there was not a constant gradual rise in sea levels and creating a curve on a piece of paper is simply a process of joining two dots.

Secondly, dating the skeleton's teeth did not go too well it seems and so C14 was brought to the table, substituting the uranian thorium methodology that didn't produce the desired outcome. The C14 data came out at 12,900 years ago - which is probably a fair reflection of reality. However, the bones of the skeleton were mineralised as a result of being emersed in a limestone cave - and all that drip drip from the walls and the ceiling. Tiny accumulations of calcite were 'accurately' dated, we are told, by uranium thorium methodology - and these came up with 12,000 years ago. So, three kinds of dating were used to confirm or reach the date, in the Younger Dryas period - or slightly before that climate phase. This is not mentioned - should it be? I don't know, but there might be a bearing on how the skeleton got down to the bottom of the cave in the first place. It fell, of course, and that is all the researchers could tell.

See also www.eurekalert.org/pub_releases/2014-05/nu-ooo051314.php