Preliminary report on research of the Casa de Pedra shell mound, São Francisco do Sul, Santa Catarina, Brazil

Abstract Babitonga Bay has a rich archaeological heritage, with a large number of sambaquis (shell mounds) related to pre-colonial fishermen-hunter-gatherers (±160 sites). The current project focuses on a sambaqui located in a cave on the east coast of São Francisco do Sul in the state of Santa Catarina known as the ‘Casa de Pedra’ mound. The site contains an archaeological matrix 38 cm thick and 27 m2 in area; excavation has been underway since 2015, in 5 cm deep levels over 30 1 x 1 m sectors to obtain samples for archaeological analysis. The matrix is predominantly composed of fish bone fragments and shells. Some calcined human bones were found scattered in the upper layers. Shells and human bones found at 3 cm and 20-25 cm depth were dated at approximately 4.460 ± 30 and 5.470 ± 30 years BP. However, sediment dating below the site indicated 4.330 ± 700 and 5.670 ± 850 years BP, leading us to question the origin of the archaeological matrix and its position in the temporal context. Some paintings were seen on the walls of the cave, which after further study may prove to be the first paintings of this type in the state and perhaps the first in Brazil associated with sambaquis.