Reservoir Effect of the Southern and Southeastern Brazilian Coast

Ângulo, Rodolfo José; Souza, Maria Cristina de; Reimer, Paula J.; Sasaoka, Sueli K

doi:10.1017/s0033822200052206

Cited by 97 publications

(82 citation statements)

References 14 publications

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“…At the Boqueirão and Usiminas archaeological sites, the age differences between charcoal and shell range between 565 ± 44 and 281 ± 44 14 C yr, which are similar to the reservoir effect ages obtained for southeastern Brazilian surficial coastal waters using shells collected before nuclear explosions in the atmosphere that range between 656 ± 46 and 320 ± 44 14 C yr (Nadal de Massi 2001; Eastoe et al 2002;Angulo et al 2005). Looking at the sampled site locations, there is apparently no correlation between reservoir effect and the expected exposure to upwelling waters that could induce a higher reservoir effect.…”

Section: Resultssupporting

confidence: 76%

A Tentative Determination of Upwelling Influence on the Paleo-Surficial Marine Water Reservoir Effect in Southeastern Brazil

et al. 2007

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ABSTRACT. Previous work has suggested that seasonal and interannual upwelling of deep, cold, radiocarbon-depleted waters from the South Atlantic has caused variations in the reservoir effect (R) through time along the southern coast of Brazil. This work aims to examine the possible upwelling influence on the paleoreservoir age of Brazilian surficial coastal waters based on paired terrestrial/marine samples obtained from archaeological remains. On the Brazilian coast, there are hundreds of shell middens built up by an ancient culture that lived between 6500 to 1500 yr ago, but there are few shell middens located on open-coast sites with a known upwelling influence. Three archaeological sites located in a large headland in Arraial do Cabo and Ilha de Cabo Frio on the southeastern coast of Brazil, with open-ocean conditions and a well-known strong and large upwelling of the Malvinas/Falkland current, were chosen for this study. The 14 C age differences between carbonized seed and marine samples varied from 281 ± 44 to 1083 ± 51 14 C yr. There are also significant age differences between carbonized seed samples (977 14 C yr) and marine samples (200 and 228 14 C yr) from the same archaeological layer that cannot be explained by a reservoir effect or an old-wood effect for charcoal. Therefore, the present data from the southeastern Brazilian coast are inconclusive for identifying an upwelling effect on R. To do so, it would be necessary to more precisely define the present-pre-bomb R in upwelling regions, and to analyze paired marine/terrestrial samples that are contemporaneous beyond doubt.

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Section: Resultssupporting

confidence: 76%

A Tentative Determination of Upwelling Influence on the Paleo-Surficial Marine Water Reservoir Effect in Southeastern Brazil

et al. 2007

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“…Chronology was established using bulk organic matter radiocarbon AMS dating (Angulo et al, 2005). The age control was made using CALIB software.…”

Section: Sediment Core Dating and Stratigraphymentioning

confidence: 99%

“…Twelve samples from the core CF02-02A were dated at the L.M.C.14 Laboratory (UMS2572-Laboratoire de Mesure du Carbone 14, CNRS/IRD/CEA/IRSN/MC, Saclay-France). Radiocarbon dating was based on bulk organic matter, and radiocarbon ages were calibrated using CALIB 5.0.1 software (http://calib.qub.ac.uk/calib/) and applying the regional reservoir effect correction (ΔR = 8 ± 17), according to Angulo et al (2005). This correction is very similar to that estimated by the Marine Reservoir Correction Database (http://calib.qub.…”

Section: Sediment Core Dating and Stratigraphymentioning

confidence: 99%

South Tropical Atlantic anti-phase response to Holocene Bond Events

Evangelista¹,

Gurgel²,

Sifeddine³

et al. 2014

Palaeogeography, Palaeoclimatology, Palaeoecology

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Records of the climatic impacts of the North Atlantic Bond cycles over the subtropical Southern Hemisphere remain scarce, and their mechanism is a topic of active discussion. We present here an alkenone-based reconstructed sea surface temperature (SST) of a sediment core retrieved from the Brazilian Southwestern Tropical Atlantic (SWTA), Rio de Janeiro, together with a sediment SST record from the Cariaco Basin. The sediment cores span the period 2,100 B.P. -11,100 B.P. Morlet-wavelet analysis detected marked periodic signals of~0.8,~1.7 and 2.2 kyr, very similar and with comparable phases to the hematite-stained-grain time series from the Northern North Atlantic in which the cyclic pattern was recognized as Bond cycles. Our result corroborates the modeled surface ocean anti-phase thermal relation between the North and the South Atlantic. We attribute this behavior to the slowing of the Atlantic Meridional Overturning Circulation. The relative SST warming at Rio de Janeiro and the relative cooling at Cariaco were comparatively more pronounced during the early Holocene (from 11 to 5 kyr B.P.) than in more recent time.

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“…Calibrated ages of marine samples (preserved bivalve shells, corals, specimens of the planktonic foraminifer Globigerinoides ruber on core 7485 and the benthic foraminifer Elphydium sp on core SSB01) were calculated using Calib software, version 5.0.2html, available at http://calib.qub.ac.uk/calib/. We employed the standard marine correction of 408 years and a regional reservoir effect of R = 12 ± 60, corresponding to the average value of eleven samples reported for the SE Brazilian coast between the latitudes 23 • S and 28 • S (Nadal de Masi 1999, Eastoe et al 2002, Angulo et al 2005) and the Marine04 Calibration Dataset (Hughen et al 2004). For terrestrial material, the Southern Hemisphere Calibration Curve (McCormac et al 2004) was used.…”

Section: Methodsmentioning

confidence: 99%

Radiocarbon geochronology of the sediments of the São Paulo Bight (southern Brazilian upper margin)

Mahiques

Sousa

Burone

et al. 2011

An. Acad. Bras. Ciênc.

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The aim of this work was to generate an inventory of the data on radiocarbon datings obtained from sediments of the São Paulo Bight (southern Brazilian upper margin) and to analyze the data in terms of Late Quaternary sedimentary processes and sedimentation rates. A total of 238 radiocarbon datings from materials collected using different sampling procedures was considered for this work. The sedimentation rates varied from less than 2 to 68 cm.kyr -1 . The highest sedimentation rate values were found in a low-energy (ría type) coastal system as well as in the upwelling zones of Santa Catarina and Cabo Frio. The lowest rates were found on the outer shelf and upper slopes. Our results confirm the strong dependency of the shelf currents, with an emphasis to the terrigenous input from the Río de La Plata outflow which is transported via the Brazilian Coastal Current, as well as of the coupled Brazil Current -Intermediate Western Boundary Current (BC-IWBC) dynamics on the sedimentary processes. At least three indicators of the paleo sea level were found at 12200 yr BP (conventional radiocarbon age) (103 meters below sea level -mbsl), 8300-8800 cal yr BP (13 mbsl) and 7700-8100 cal yr BP (6 mbsl).

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Reservoir Effect of the Southern and Southeastern Brazilian Coast

Cited by 97 publications

References 14 publications

A Tentative Determination of Upwelling Influence on the Paleo-Surficial Marine Water Reservoir Effect in Southeastern Brazil

A Tentative Determination of Upwelling Influence on the Paleo-Surficial Marine Water Reservoir Effect in Southeastern Brazil

South Tropical Atlantic anti-phase response to Holocene Bond Events

Radiocarbon geochronology of the sediments of the São Paulo Bight (southern Brazilian upper margin)

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