If you are a Atlantis fan... you will know when Atlantis sank
due to catastrophic climate and natural disaster, a lot of those
Atlanteans sail out from all direction to seek refuge. So Xinjiang
could just be one of the stop they step in and start to educate the
natives there and inter-breeding start from there.
Similar stuff has occured in South America and the Eygpt and etc
etc. The sudden explosion in technology and technical know how
cannot be through years of training. It must be from a teacher
source from an advanced civilisation and that is the Atlantis
people 
According to Edgar Cayce through readings, Atlanteans are typical
fair and tall and look Caucasian and that can explain the Xinjiang
ppl with Caucasian features due to inter-breeding between natives
and the Atlanteans.
