Dating of fossil human teeth and shells from Toca do Enoque site at Serra das Confusões National Park, Brazil.

This work reports the dating of a fossil human tooth and shell found at the archaeological site Toca do Enoque located in Serra das Confusões National Park (Piauí, Brazil). Many prehistoric paintings have been found at this site. An archaeological excavation unearthed three sepulchers with human skeletons and some shells. Two Brazilian laboratories, in Ribeirão Preto (USP) and Recife (UFPE), independently performed Electron Spin Resonance (ESR) measurements to date the tooth and the shell and obtain the equivalent dose received by each sample. The laboratories determined similar ages for the tooth and the shell (~4.8 kyBP). The results agreed with C-14 dating of the shell and other samples (charcoal) collected in the same sepulcher. Therefore, this work provides a valid inter-comparison of results by two independent ESR-dating laboratories and between two dating methods; i.e., C-14 and ESR, showing the validity of ESR dating for this range of ages.

Archeometric studies in the Franciscan Convent of "Santo Antônio" (Recife, PE).

The purpose of this paper is to characterize the tiles placed on the walls of the Franciscan convent of "Santo Antônio" (Recife-PE) and to obtain information about the several expansions and structural reforms performed on the convent by dating the bricks. For this purpose, a portable energy dispersive x-ray fluorescence (EDXRF) was used to characterize the tiles. The dating of the bricks was performed using the Thermoluminescence (TL) technique. The results of the EDXRF analysis show that the dominant component of the white pigment is lead [2PbCO(3)·Pb(OH)(2)], used since the ancient times until the 20th century, while the dominant element of the blue pigment is cobalt (CoO·Al(2)O(3)), that has been used from 1807 until nowadays. The TL dating of bricks indicate that there were walls with different periods of construction, being one built around 1765, with a deviation of 28 years, whereas other was built later, around 1874, with a deviation of 15 years. These results provide new data towards understanding how and when the Recife Franciscan convent of "Santo Antônio" was designed and built, contributing to other research works presently underway on site.