Environmental reconstruction spanning the transition from hunter/gatherers to early farmers in Colombia: paleopedological and archaeological indicators from the pre-ceramic sites Tequendama and Aguazuque

Abstract

Complex geoarchaeological research of the archaeological sites with continuous long-term occupation could provide insight into environmental change and human-landscape interaction during the transition from hunter-gatherer to horticulture economy in the north-west of South America. We performed a paleopedological study in the new sections at Tequendama (rockshelter site) and Aguazuque (open-air site) two key pre-ceramic sites of the Savannah of Bogotá region of Colombia, combined with traditional archaeological and paleontological investigations. The chronological scales of the sections based on a large number of 14C dates show that their occupation periods are complementary and together cover the period from the terminal Pleistocene to late Holocene. The material of the archaeological layers has a colluvial origin with large tephra input. Presence of volcanic components influence pedogenesis supporting development of granular structure, dark humus accumulation, and Andic properties that could not be used for paleoenvironmental reconstruction. Micromorphological observations however show abundant evidence of pedogenic carbonate accumulation that we interpret as evidence of gradual aridization during the middle Holocene. This conclusion is supported by the paleontological data, an upward increase of the frequency of Cavia sp. remains, and agrees with the regional palynological proxies. Aridization was the background environmental trend during the transition period from a hunter-gatherer economy to an early horticulture and plant and animal domestication.