Seasonal Variations in Peruvian Marine Reservoir Age from Pre-Bomb Argopecten Purpuratus Shell Carbonate
2007; Cambridge University Press; Volume: 49; Issue: 2 Linguagem: Inglês
10.1017/s0033822200042740
ISSN1945-5755
AutoresKevin B. Jones, Gregory Hodgins, David L. Dettman, C. Fred T. Andrus, April Nelson, Miguel F. Etayo-Cadavid,
Tópico(s)Coral and Marine Ecosystems Studies
ResumoMarine upwelling along coastal Peru can be intense and variable, making radiocarbon dating marine and coastal systems complex. Historical and proxy records of upwelling along coastal Peru are few, and long-lived species such as corals do not grow in the cold coastal waters. Mollusk shell carbonate, however, can record both the magnitude of the local marine reservoir correction, ΔR, and of seasonal oscillations in the ventilation age of coastal waters. If large, these seasonal oscillations would complicate radiocarbon dating of marine organisms. To examine this possibility, we sampled for δ 13 C, δ 18 O, and 14 C content a set of pre-bomb Argopecten purpuratus shells collected from coastal Peru during 1908 and 1926. Intrashell variations of up to 216 14 C yr were noted, but these were not consistently correlated with seasonal changes in δ 18 O or δ 13 C. Only an 11 yr difference was observed in the weighted average ΔR of Callao Bay shells collected during normal (1908) and El Niño (1926) years. Despite the intrashell 14 C variation noted, weighted average ΔR values from all 3 sample sites and from normal and El Niño years all overlap at 1 σ. We report ΔR values of 183 ± 18 and 194 ± 23 yr from Callao Bay (12°4′S), 165 ± 24 yr from Salaverry (8°14′S), and 189 ± 23 yr from Sechura Bay (5°45′S).
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