This site has a wealth of info on J.
www.jogg.info/42/files/logan.htm
Heres the haplogroup page on eupedia.
http://www.eupedia.com/europe/origin...pe.shtml#mtDNA
Also this thread disscusses, post glacial Mtdna, which involves J.
http://www.eupedia.com/forum/threads...amp-Mesolithic
Hope this helps.