[BR-Crater] Columnar jointed rocks State of the Research-January 2009

[Scot Wilcoxon]

Some information is actually available because of the melt process.  For 
example, in some kinds of rock the process of radioactive decay creates 
marks inside the rock.  Counting those marks can identify when the rock 
cooled, because the tracks are destroyed above a certain temperature.
> help with it.  I thought too much information would have been lost in the
> melting process for that to be a good choice.  But if it turns out to be
>
>