Further to the tolos and kurgan post from Gerry and in relation to the
identification of the tolos with the Halafian culture, I can only
recommend you check out
http://www.xs4all.nl/~tank/kurdish/htdocs/his/o
rig.html on
Exploring Kurdish Origins
by Mehrdad R. Izady (Harvard University Lecture 10 March 1993)
Not only is it an excellent discussion on such topics as
Hurrian-Hittite and Iranian penetration - it gives the best history of
the Kurds that I have ever seen. It is a brilliant piece of work (and
comes close to identifying who the Sumerian substrate was as well.
Follow it up.
Regards
John