Mike,
There are over 200 subfloor burials at ElMina, Ghana,
dating from the 17th to late 19th centuries. These are mentioned
by Christopher DeCorse in 1992 "African Archaeological Review"
vol. 10 pp. 163-196 and 1993 "African Archaeological Review" vol.
11 pp. 149-173. For Jamaica there is Roderick McDonald's book
"The Economy and Material Culture of Slaves" (Louisiana State
U.P. 1993) which mentions late 18th century subfloor burials by
slaves. Is the burial you excavated from within a structure, or
in a yard?
Ross Jamieson
Department of Archaeology
University of Calgary, Canada