Models of Southeast Asian prehistoric cultural development based on recent excavations in North and Northeast Thailand hypothesize that early village farming arose from the indigenous Hoabinhain occupation. The Petchabun Piedmont Survey was designed to test the particular idea expressed in those recent models that agriculture developed in a piedmont setting and in the form of a transition between mountain-oriented Hoabinhian hunting and gathering, and plains-oriented village farming. The survey covered eleven 10 x 10 km grid squares along the western piedmont borders of the Khorat Plateua, Northeast Thailand. Forty five sites were recorded and, subsequently, test excavations were conducted on three of these sites. The three excavated sites had similar ceramics and similar assemblages of other artifacts. Carbon-14 dates range in the first millenium B.C. Similarities between the excavated ceramics and surface ceramics from other sites demonstrate that most, and suggest that all, of the prehistoric open sites found in the survey pertain to the same cultural cluster. These were designated Phu Kradung ceramic sites. Four sites from an adjacent area surveyed by the Pa Mong project were also recognized as Phu Kradung ceramic sites. Neither the Petchabun Piedmont Survey nor the literature provide any evidence for Hoabinian, transitional, or early village farming occupation of this particular piedmont zone. Two major conclusions were drawn. First, extant models of Southeast Asian cultural development need to be reevaluated. Alternatives are discussed and another model is introduced in which agriculture arose from a shift in the subsistence base of hypothetical early plains occupants. Second, the survey results and current literature demonstrate that the Southeast Asian Iron Age witnessed settlement expansion and development of key elements of the enormously important wet rice agricultural complex. Data from the period are reviewed and some concluding suggestions are made as to their theoretical significance for studies of cultural development in Southeast Asia
