Identification of Postdepositional Secondary Calcite in Archaeological Ceramics from Sanagasta Culture through SEM-EDS (Tinogasta, Catamarca, Argentina).

DE LA FUENTE, G. A. AND A. C. CARRERAS

Cabo Frio, Rio de Janeiro, Brasil

Congreso; SARX 2008 - XI Latin American Seminary of Analysis by X-Ray Techniques; 2008

Postdepositional secondary calcite (CaO3) has been identified in archaeological ceramics using several analytical techniques [1, 2, 3, 4]. Although secondary calcite has not been a problem for chemical characterization of archaeological ceramics at Northwestern Argentine due to the low concentrations of Ca observed in most of the analyses, it is necessary to develop a complementary approach to determine when we are observing the presence of primary or secondary calcite in archaeological ceramics. The presence of calcite (CaO3) as secondary phase has been cited by some authors [1, 2]. However, the identification and interpretation of secondary calcite have been always controversial and there are no clear and unified criteria for proper identification. In most of non-calcareous archaeological ceramics the presence of calcite comes from alocthonous or postdepositional sources and the subsequent recrystallization of mineral phases basically after firing. Secondary calcite presents three types of crystallization: (1) geodic facie, (2) microgranular aggregates, and (3) cryptocrystalline calcite, all of them present in ceramic pores and microfractures. In this paper, we will show how SEM-EDS analytical technique is a powerful tool for the proper identification of recrystallized secondary calcite in archaeological ceramics from Sanagasta Culture (Late Period, ca. AD 900 – AD 1100), Abaucán Valley, Dept. of Tinogasta, Province of Catamarca, Northwestern Argentine. Additionally, it will be showed how SEM-EDS can help to the study of the main micromorphological characteristics of this postdepositional mineral phase.