Dating Rocks

5 Nov 2010

At www.physorg.com/print207997095.html ... we are told geologists have a general idea of when major events occurred in earth history but precise dates for the sequence and duration of geological events are not actually known for sure. As an example, how long did it take for mountain ranges to forme or the exact age of fossils. Geochronologists are thescientists who determine the age of rocks and minerals and to do this they measure radioactive elements. In the laboratory a tracer is added - a solution containing synthetic radioactive elements. The problem is that different laboratories use different tracers which makes it difficult to compare data with precision. A new tracer has been developed in the hope it will become the standard. However, as far as the general public are concerned it will not alter things to any discernable degree - big numbers will still be produced. It is interesting only so far as the description of the methodology is concerned - and its fragility (see also http://web.mit.edu/newsoffice ).