Shell sclerochronology and stable isotopes of the bivalve Anomalocardia flexuosa (Linnaeus, 1767) from southern Brazil: Implications for environmental and archaeological studies
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Data
2017
Tipo de documento
Artigo de Periodico
Título da Revista
ISSN da Revista
Título de Volume
Área do conhecimento
Ciências Exatas e da Terra
Modalidade de acesso
Acesso embargado
Editora
Autores
Colonese, André Carlo Colonese
Netto, Sergio Antônio
Francisco, André Silva Francisco
Orientador
Coorientador
Resumo
This study presents the first stable isotopic and sclerochronological calibration of the bivalve Anomalocardia
flexuosa (Linnaeus, 1767) in relation to environmental variables in a subtropical coastal area of southern Brazil.
We investigate incremental shell growth patterns and δ18O and δ13C values of modern specimens collected
alive fromthe Laguna Lagoonal System (LLS). Shells of Anomalocardia flexuosa are also one of themain biological
components of pre-Columbian archaeological shell mounds and middens distributed along the Brazilian coastline.
We therefore selected archaeological specimens froma local late Holocene shell mound (Cabeçuda) to compare
their stable carbon and oxygen isotope values with those of modern specimens. Shell growth increments,
δ18O and δ13C values respond to a complex of environmental conditions, involving, for example, the effects of
temperature and salinity. The isotopic information extracted from archaeological specimens from Cabeçuda
shell midden in the LLS indirectly indicates that environmental conditions during the late Holocene were different
frompresent day. In particular, intra-shell δ18O and δ13C values of archaeological shells reveal a stronger marine
influence at 3 ka cal BP, which is in contrast to the seasonal freshwater/seawater balance that currently
prevails at the LLS.
Palavras-chave
Coastal lagoon, Anomalocardia flexuosa, Laguna, Sclerochronology, Salinity