Quartz OSL dating of ancient ceramics fragments from the Churajon archaeological complex in Arequipa, Peru

Ancient pottery fragments from the Churajon archaeological complex, Arequipa, Peru, were analyzed by OSL, XRD, and XRF techniques to provide absolute chronology, crystalline structure, and elemental composition. The fragments with base and rim have been projected with design techniques used in archaeology to find the type of vessel to which it belongs. After chemical treatment of the ceramic fragments, quartz grains were obtained. The analysis of the diffraction patterns obtained by the XRD technique of these grains corresponds to that of silicon dioxide SiO₂. By the XRF technique, SiO₂, Al₂O₃, and Fe₂O₃ have been observed as the main components. For equivalent dose (D_e) determination, SAR protocol was employed. For the dose rate (D_r) determination, the ²³²Th, ²³⁸U, and ⁴⁰K- concentrations within the ceramic and of the surrounding sediments were measured using the gamma spectroscopy technique. The ages of the ceramic fragments found range from the colonial era (from 1530 to 1821 A.D.) to the eruption of the Huaynaputina volcano (1600 A.D.) with an Engobated and Simple Churajon style. The oldest pottery dated to 1043 ± 198 yr, which corresponds to the Late Intermediate period with a Middle Churajon style (1200–1350 A.D.).