Archaeological remains traditionally are defined in terms of
time, space, and style. Without absolute dating, style was useful
for defining related archaeological materials, but positioning
defined units of style in time often proved problematic. Concerns
over chronology dominated much early archaeological work in
various parts of the world (5–7), especially because often it was
difficult to relate spatially separated archaeological remains to
each other. Although stratigraphy and seriation could be used to
provide relative dating for past remains, cross-dating between
sites was challenging.