There are some photographs of wooden chimneys in several of the publications
of WPA slave interviews and I think in Vlach's book Back of the Big House.
These were extant slave cabins, primarily in the Carolinas and Georgia, I
think.
 
I have some vague recollection of a slave cabin excavation that showed
postholes interpreted as wooden chimneys.  Again, it seems to me it was one
of the South Carolina projects, but I'm not sure about that.  You might
check some of the literature on slave site excavations since this type of
chimney seems to have been frequently used on cabins.  We suspected the
presence of this type of chimney at our Dunes West excavations in Mt.
Pleasant, SC with brick footers supporting wattle-and-daub or log-and-clay.
This was based on too few bricks for a brick chimney, a finished looking
base, and daub fragments.
 
                                        Lucy Wayne