Pottery kilns and firing technology during Late and Inka Periods in the southern sector of the Abaucán Valley: a contribution through ceramic petrography and XRD (Catamarca, Northwestern Argentina, Southern Andes)

Abstract

The conservation of combustion structures for firing archaeological pottery kilns- is rather rare at Northwestern Argentine region. With the exception of Batungasta archaeological site (middle sector of Abaucán Valley, Tinogasta, Catamarca, Argentina), the conservation of this type of archaeological structures is scarse. At southern sector of Abaucán Valley, in the surroundings of SaCat01 archaeological site, so-called Costa de Reyes Nº 5, an Inka site, around 6 combustion structures with different degrees of conservation were located during fieldwork in 2010. The survey and excavation of two of these structures allowed us to develop further technological studies related to its configuration and the temperatures reached inside them, as well as to radiocarbon date one structure, Unit 3H, from Late Period (ca. AD 900 ? AD 1450). In this paper, we present the results obtained through archaeometric analyses by ceramic petrography and X-ray diffraction carried out on wall remains of these combustion structures. The data obtained point towards the existence of several degrees of vitrification in the walls of these pottery kilns as well in some of the sherds analysed. The presence of neoformation mineral phases like wollastonite (CaSiO3), diopside (CaMgSi2O7), gehlenite (Ca2Al2SiO7), and hematite (Fe2O3) indicate that these combustion structures reached high temperatures ranging between 900ºC and 1000ºC / 1100ºC.