Update 1: follow-on post here on the series revisiting maps or posting off-web.
Update 2: added an intriguing speculation on the adjacent Sudbury Nickel Irruptive
Following on Parts I & II here & here, here is an article on the breakup of Nuna Province in current N China: it gives new impetus to plate tectonics around 1.5GA - see Part II for another example - such dynamic processes were proposed in my thesis paper over 40 yrs. ago here, where I applied recent plate dynamics to the Proterozoic of Southern Province of N Ontario Canada of similar age and make-up of Nuna Province. I looked at it from a structural geologic perspective, using intrusives cross-cutting relationships as date markers. The new paper actually dated similar intrusives in present day N China.
