Prehistoric Agricultural Terraces in the Rio Japo Basin, Colca Valley, Peru

TitlePrehistoric Agricultural Terraces in the Rio Japo Basin, Colca Valley, Peru
Publication TypeThesis
Year of Publication1998
AuthorsBrooks, S. O.
Academic DepartmentGeography
Number of Pages545
UniversityUniversity of Wisconsin
CityMadison
Thesis TypeUnpublished Ph. D. Dissertation
Call NumberAAT 9911668
AbstractPrehispanic agricultural terraces in the Peruvian Andes probably originated at least as early as 4350 ± 80 BP in the Japo, Basin in the Colca Valley in southern Peru. This dissertation examines the origins and development of agricultural terraces in the Río Japo Basin. Over time the transition was made from rainfed cross channel terraces, to rainfed sloping field terraces, to rainfed linear bench terraces, each of which also benefited from precipitation runoff. Systematically irrigated bench terraces were probably constructed after the rainfed linear bench terraces proved inadequate as a result of the combined impact of the colder temperatures that occurred during the Little Ice Age and an ongoing dry period. When the frost line descended the mountain slopes during the Little Ice Age, the amount of land that had previously been cultivated was reduced by up to 50 percent. Rather than reduce population numbers or move elsewhere, the Collaguas culture that inhabited the Río Japo Basin during the Late Intermediate Period (AD 1000–1470) responded to the climatic crisis by constructing the 34-km Huarancante Canal that carries snow melt from the Cerro Huarancante snow mass to the terraces in the valley. People have choices and options from which they select when confronted with adversity. This dissertation demonstrates that when faced with nearly half of their agricultural terraces being removed from production, the Collaguas culture did not collapse, but instead met the challenge by constructing major canals to snow caps and by switching from rainfed terraces to systematically irrigated terraces. Collaguas ceramics and architecture are presented and discussed along with the diagnostic characteristics of each. The enormous Cotallaulli obsidian quarry that provided obsidian for arrow and spear points in southern Peru and northern Bolivia was found and documented in March 1994. Evidence that obsidian from the Cotallaulli source in the Colca Valley was traded to other sites in the south central Andes as early as 8850 BP is also presented. Contemporary agriculture in the Colca Valley is described. A brief history of terracing in Peru is presented along with theories of terrace of terrace origins.