scholarly journals The effect of coastal landform development on decadal-to millennial-scale longshore sediment fluxes: Evidence from the Holocene evolution of the central mid-Atlantic coast, USA

2021 ◽  
Vol 267 ◽  
pp. 107096
Author(s):  
Justin L. Shawler ◽  
Christopher J. Hein ◽  
Chloe A. Obara ◽  
Mahina G. Robbins ◽  
Sebastien Huot ◽  
...  
2014 ◽  
Vol 86 (2) ◽  
pp. 671-683 ◽  
Author(s):  
JOÃO WAGNER A. CASTRO ◽  
KENITIRO SUGUIO ◽  
JOSÉ C.S. SEOANE ◽  
ALINE M. DA CUNHA ◽  
FABIO F. DIAS

The present paper aims to investigate the relative sea-level and the coastal evolution during the Holocene in the Rio de Janeiro coastline, based on geological and biological indicators. Using topographic survey, excavation and coring, and 14C dating of these coastal deposits and beachrocks outcrops, we have reconstructed a sea-level curve for the Holocene. For the first time on the Brazilian coast it was identified a negative record of relative sea-level during Late Pleistocene and Early Holocene transition. After the transition, a relatively rapid increase of sea-level began. At approximately at 8500 cal yr BP, the sea-level was 0.5 m below the current level, was overtaken for the first time in the Holocene, at approximately 7500 cal yr BP. The maximum level of +2.5 m was reached between 4770 and 4490 cal yr BP. At the point of maximum transgression, the sea-level began a general behavior of lowering until the present. These results confirm other data already obtained elsewhere along the Atlantic coast of South America. The results of this study are consistent with previous researches and they help to refine the Holocene sea-level record along the Brazilian coast.


2014 ◽  
Vol 41 (12) ◽  
pp. 4300-4307 ◽  
Author(s):  
Paige E. Newby ◽  
Bryan N. Shuman ◽  
Jeffrey P. Donnelly ◽  
Kristopher B. Karnauskas ◽  
Jeremiah Marsicek

Radiocarbon ◽  
2015 ◽  
Vol 57 (4) ◽  
pp. 517-525 ◽  
Author(s):  
Eduardo Alves ◽  
Kita Macario ◽  
Rosa Souza ◽  
Orangel Aguilera ◽  
Ana Carolina Goulart ◽  
...  

The Saquarema archaeological site, on the Atlantic coast of the Rio de Janeiro State, is one of many shellmounds built on the Brazilian coast by hunter-gatherer populations during the Holocene. We used archaeological material from this site with the aim of evaluating the marine reservoir effect (MRE) in the region. Radiocarbon ages of 45 marine and 6 terrestrial samples from this shellmound provided data for assessing the MRE and the influences of freshwater and seasonal coastal marine upwelling in this specific locality. Samples of charcoal, fish otoliths, and mollusk shells were analyzed and the 14C dates were modeled in the OxCal platform to determine the marine reservoir correction. The result obtained is R = 265 ± 70 14C yr and the offset ΔR was found to be –140 ± 66 14C yr. To support the accuracy of this value for correcting conventional 14C marine ages, taxonomic analyses of the samples were performed.


2019 ◽  
Vol 211 ◽  
pp. 93-106 ◽  
Author(s):  
Christophe Colin ◽  
Nadine Tisnérat-Laborde ◽  
Furu Mienis ◽  
Tim Collart ◽  
Edwige Pons-Branchu ◽  
...  

2019 ◽  
Vol 183 ◽  
pp. 103028
Author(s):  
Keiji Horikawa ◽  
Tomohiro Kodaira ◽  
Ken Ikehara ◽  
Masafumi Murayama ◽  
Jing Zhang

2002 ◽  
Vol 35 ◽  
pp. 306-312 ◽  
Author(s):  
Barbara Delmonte ◽  
Jean Robert Petit ◽  
Valter Maggi

AbstractMeasurements of the concentration and size distribution of dust particles found in the EPICA (European Project for Ice Coring in Antarctica) Dome C ice core, East Antarctica, provide records covering the last 27000 years. the total concentration decreased drastically by a factor of 55 from the Last Glacial Maximum (LGM) (800 ppb) to the Holocene (15 ppb), with a well-marked absolute minimum around 11500–11600 years ago. This latter almost corresponds to the end of the Younger Dryas in Greenland, which was marked by a methane peak related to the expansion of tropical wetlands. Assuming that the source region forAntarctic dust is the southern part of South America, the Antarctic dust minimum suggests a larger geographical extent for this wet period. the volume (mass)-size distribution of the particles displays a mode which is close to 2 μm in diameter, shifting from 1.9 μm in the glacial period to 2.07 μm in the Holocene. As opposed to previous results from old Dome C, EPICA suggests a greater proportion of large particles in Holocene samples than in LGM samples. In addition, for the period 13 000–2000BP, structured millennial-scale oscillations of the dust mode appear. These are especially well marked before 5000 years ago, with higher frequencies also present. the difference between LGM and Holocene particle distributions may be related to changes in the pattern of dust transport to East Antarctica. At Dome C the greater proportion of coarse particles observed during the Holocene suggests greater direct meridional transport. During the LGM, atmospheric circulation was likely more zonal, causing a greater amount of large dust particles to be removed from the atmosphere before reaching Antarctica. Changes in atmospheric circulation could also be the cause of the millennial-scale dust-mode oscillations during the Holocene.


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