Aleksander Borejsza

Chronology, Subsistence, and the Earliest Formative of Central Tlaxcala, Mexico

We propose that pottery-using villages did not appear in the upland Apizaco region of central Tlaxcala, Mexico, until after 1000 B.C., centuries after such developments in choice locations for maize agriculture. We excavated at two of the earliest known Formative sites in the region. That work revealed abundant intact refuse deposits, allowing us to evaluate an exist ing ceramic chronology with new radiocarbon dates as well as characterize Formative subsistence. Our results support a more general model of emerging sedentism in central Mexico involving population dispersions from prime agricultural areas to zones of higher elevation. The earliest pottery-using agriculturalists in Apizaco were probably migrants from adjacent regions.

SWIDDEN AGRICULTURE IN THE TIERRA FRÍA ? EVIDENCE FROM SEDIMENTARY RECORDS IN TLAXCALA

Abstract Swidden agriculture in Mesoamerica is commonly associated with the hot and humid lowlands and with small isolated communities. Charcoal-rich sediments discovered in Tlaxcala, however, suggest that it was practiced in the cold highlands in the Formative and Classic periods. The headwaters of the Xilomantla drainage incised a nine-meter deep channel shortly before 200 b.c., in response to increased runoff from slopes degraded by agriculture. It was filled back within a few hundred years with sands and muds containing recurrent laminae of charred plant matter that reflect the annual burning of secondary scrub in fallowed fields. A gully in the La Ladera drainage received high inputs of charcoal from the surroundings of a nearby settlement between ca. a.d. 400 and 900. The farming practices inferred from these deposits have no exact ethnographic analog. They inflicted lasting environmental damage, but were upheld for several centuries despite changes in settlement patterns.