CHARACTERISATION and OSL DATING of an ANCIENT BRICK WELL at PATTARAIPERUMBUDUR, TAMIL NADU, INDIA

Abstract

This paper is about characterizing a brick sample obtained from the brick well at Pattaraiperumbudur, a recently excavated site in Tiruvallur, Tamil Nadu. The petro-archaeometry studies of this site included the findings about its elemental constitution, mineralogical composition, thermal changes and physical properties. The elemental constitution was determined using an XRF test, while the mineral composition was found with the help of XRD and FT-IR, showing the chemical bonding at various peaks. A material can undergo different thermal reactions at various temperatures and the effect of temperature on the sample was screened through a TG-DTA analysis. Optical microscopy (OM) is one of the important tests used in petro-archaeological studies, confirming the XRD results. The morphology of the sample was studied with the aid of FE-SEM, which provided an idea about the porous structure and elemental composition. Physical tests of water absorption, porosity and bulk density provided information on the durability of the brick sample. The combined results of TGA and XRD suggest that the firing of the bricks had taken place below 950 °Cinan oxidising atmosphere. The chemical composition reveals that the clay contains a low amount of CaO and the flux concentration is greater than 9 %, indicating low refractory. The extracted brick samples were subjected to carbon dating using optically stimulated luminescence (OSL) that found them to be 2100 years old. 3D rendering of the well was created with the help of the H-BIM tool.