HOLOCENE EVOLUTION OF A WAVE-DOMINATED BARRIER-LAGOON SYSTEM IN RIO DE JANEIRO, BRAZIL

Radiocarbon ◽  
2020 ◽  
pp. 1-17
Author(s):  
Rafael Cuellar de Oliveira e Silva ◽  
Gilberto Tavares de Macedo Dias ◽  
Rodrigo Coutinho Abuchacra ◽  
Sérgio Cadena de Vasconcelos ◽  
Kita Chaves Damasio Macario ◽  
...  
Keyword(s):  
Sea Level ◽  
Coastal Plain ◽  
Rio De Janeiro ◽  
Marine Transgression ◽  
Sea Level Variation ◽  
South Wales ◽  
New Construction ◽  
Percussion Drilling ◽  
Prior Models

ABSTRACT In a wave-dominated coast, most of the Jacarepaguá coastal plain is occupied by buildings. During a new construction in this region at Barra da Tijuca, the subsurface area was excavated, exposing its quartzose sand nature, with a high mollusk shell concentration and in situ echinoderms at –10 m depth. The possibility to access this area encouraged us to investigate the evolution of the coastal plain. A 7.84-m-long core was recovered by percussion drilling. Stratigraphic, grain size, and geochemical analysis were undertaken. Three carbonate samples were dated by radiocarbon accelerator mass spectrometry (14C AMS). The revised sea-level variation curve revealed that the last postglacial marine transgression reached the present mean sea-level at 7945–7500 cal BP. The sandy deposit bottom was an ancient shoreface, with in situ echinoderms buried at 7770–7540 cal BP by the Pleistocene inner barrier reworking due to the last marine transgression. The Holocene outer barrier-lagoon and its flood tidal delta were formed from 5440–5070 cal BP. Mid-Holocene marine regression allowed the outer barrier progradation and the lagoon shallowing/infill. This paper confirms prior models proposed by other researchers for the Rio de Janeiro central coast and shows its similarity with the New South Wales coast, Australia.

Evidence of High Sea Level during Isotope Stage 5c in Queensland, Australia

1985 ◽  
Vol 24 (1) ◽  
pp. 103-114 ◽  
Author(s):  
J. W. Pickett ◽  
C. H. Thompson ◽  
R. A. Kelley ◽  
D. Roman
Keyword(s):  
Sea Level ◽  
New South ◽  
Good Condition ◽  
Coastal Dunes ◽  
Intertidal Sediments ◽  
South Wales ◽  
Eastern Australia ◽  
Maximum Period ◽  
High Dune

Thirty-nine species of scleractinian corals have been recovered from under a high dune on the western (mainland) side of North Stradbroke Island, eastern Australia. The corals are associated with thin intertidal sediments and their good condition implies burial in situ and preservation in a saturated zone. Most likely this occurred as the coast prograded and a large dune advanced into the littoral zone, burying intertidal sediments and coral. The species assemblage indicates a sheltered environment but one open to the ocean without wide fluctuations in salinity. Three species yielded a mean 230Th/234U age of 105,000 yr B.P. which is significantly younger than the nearest Pleistocene corals at Evans Head, New South Wales. The corals provide evidence of a sea stand near present sea level during isotope Stage 5c, which is considerably higher than previously suggested for this period. Their good condition implies that the overlying parabolic dune is of comparable age and formed during that high stand of sea level. Also, the isotope age provides a maximum period for the development of giant podzols in the podzol chronosequences on coastal dunes in southern Queensland.

scholarly journals Assembleia de Moluscos da Região do Pântano do Ramalho, Cabo Frio, RJ: Indicadores Biológicos de Variação do Nível Relativo do Mar Durante o Holoceno

2011 ◽  
Vol 34 (2) ◽  
pp. 46-52
Author(s):  
Aline Meneguci da Cunha ◽  
Fábio Ferreira Dias ◽  
Vera Maria Medina da Fonseca ◽  
João Wagner de Alencar Castro
Keyword(s):  
Sea Level ◽  
Coastal Plain ◽  
Rio De Janeiro ◽  
Wide Distribution ◽  
Northern Coast ◽  
Mollusk Shells ◽  
Low Degree ◽  
Absolute Dating ◽  
Dating Method ◽  
Cabo Frio

In the coastal plain of the Una river, county of the Cabo Frio, the northern coast of the State of Rio de Janeiro, are found biological evidences of change in relative sea level during the Holocene, represented by dense accumulations and wide distribution composed predominantly of mollusk shells. This paper aims to describe a new occurrence of accumulation of mollusk shells in the region of Ramalho's marsh, coastal plain of the Una river. The study area is located within the Portal de Buzios condominium, Amaral Peixoto Highway (RJ-106) at Km 125 between the coordinates 42º03'29"W and 22 º44'53"S. The survey of altimetry database shells was performed by tracking DGPS Pro Mark 2. To perform the taxonomic analysis, paleoecological, and geochronological were collected approximately 1.75 dm³ of mollusk shells in a trench of 0.50 cm, excavated at the edge of a small dam in the area of the Portal de Búzios condominium. Approximately 100 grams of the specie Anomalocardia brasiliana shells were sent to the absolute dating method radicarbon to Beta Analytic Inc., Miami - USA. Data obtained from a DGPS Pro Mark 2 show an altitude of 0,90 m above actual sea level. Only three species of mollusks were identified in this filing: Anomalocardia brasiliana, Lucina pectinata and Crassostrea rizophorae. A. brasiliana and L. pectinata have not joined infaunal habit, live in muddy or sandy bottoms. C. rizophorae epifaunal habit has stuck, living in rocky and gravel substrata. The three species have water depths ranging from 0 to 30 m depth. Most of the shells found present a low degree of fragmentation and corrosion, indicating little or none transportation. Some shells of L. pectinata and A. brasiliana are articulated, and the shells of C. rizophorae are embedded in the shells of other species. The conventional age of the deposit is 5780 À 70 years BP, calibrated by CALIB 5.0 program in 5997-6333 cal. years BP. These data are similar ages found in deposits along the northern coast of Rio de Janeiro state, Brazil.

Coastal landforms evolution during the Holocene marine transgression: a witness from the past to understand the future

2020 ◽  
Author(s):  
Livio Ronchi ◽  
Alessandro Fontana ◽  
Annamaria Correggiari
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Coastal Plain ◽  
Adriatic Sea ◽  
Tidal Inlets ◽  
Northern Adriatic Sea ◽  
Northern Adriatic ◽  
Marine Transgression ◽  
Coastal Landforms ◽  
Lagoon Systems

<p>The continental shelves submerged during the last marine transgression could constitute a unique laboratory to analyse how coastal landforms developed and evolved within the framework of a rising sea level. Such features therefore represent precious witnesses in the light of the high rates of sea-level rise predicted for the end of the century. Unfortunately, the majority of the coastal landforms have been wiped away during and soon after their submersion as a consequence of the pervasive wave and tidal action. Therefore, only few examples of well-preserved submerged coastal landforms are available.</p><p>In this study we focused our attention on the Italian side of northern Adriatic Sea, where a wide, low-gradient continental shelf, coupled to a very rapid marine ingression, allowed the partial conservation of the transgressive coastal landforms. Such study was carried out through the analysis of almost 10,000 km of high-resolution geophysical surveys (CHIRP-sonar profiles) and tens of stratigraphic cores carried out in the area during the last 30 years.</p><p>We recognized a series of almost 100 remnants of paleo tidal inlets which formed during the post-LGM transgression that led to the submersion of the Adriatic shelf. Despite paleo tidal inlets are often almost completely erased by the wave ravinement processes, when preserved they represent ideal markers for reconstructing the timing and impact of sea-level rise on the transgressed coastal plain. A wealth of information can be obtained by their analysis, such as the paleo coastlines locations, the dimensions of the paleo lagoon systems and, in particular conditions, the relative paleo sea-level. Such features therefore represent valid means to reconstruct the impact of the transgressive sea on the coastal area.</p><p>In particular, the paleo tidal inlets recognized in the northern Adriatic Sea suggest the recurrent formation followed by rapid overstepping of large lagoon systems during the early Holocene. Moreover, these features can be subdivided into clusters based on the depth of their top, thus allowing to infer the position of a series of paleo coastlines and suggesting the occurrence of periods of stasis of the relative sea-level rise, which allowed the formation of such inlets.</p><p>Although remnants of paleo tidal inlets are common on the northern Adriatic Shelf, they are almost absent in the northernmost portion of the basin (i.e. the Gulf of Trieste), where a series of paleo fluvial systems have been identified, thus providing a direct witness on the evolution of the coastal plain during a transgressive phase and right before its rapid submersion.</p><p>This research provides new insights on two main topics: i) it improves our knowledge on the post-LGM marine transgression, therefore contributing to reconstruct the history of sea-level rise and to constrain the modelling of future behaviour; ii) it contributes to understand the evolution of tidal inlets and lagoon-barrier island systems under the forcing of high rates of sea-level rise.</p>

A Barrow on Breach Farm, Llanbleddian, Glamorgan

1938 ◽  
Vol 4 (1) ◽  
pp. 107-121 ◽  
Author(s):  
W. F. Grimes
Keyword(s):  
Bronze Age ◽  
Sea Level ◽  
Coastal Plain ◽  
Middle Part ◽  
Middle Portion ◽  
River Systems ◽  
South Wales

The Vale of Glamorgan (fig. 1, 1) is the middle part of the coastal plain of South Wales. An undulating belt of country much dissected by river systems, its highest parts consisting of knolls and ridges which rarely achieve a height of more than 400 ft. above sea-level, it was occupied fairly intensively throughout prehistoric times. Round barrows are found scattered throughout its length. But they are particularly concentrated in one area in the middle portion of the Vale, where, between the ancient towns of Llantwit Major on the coast, and Cowbridge, about six miles inland, between 20 and 30 have been recognised. None of these barrows has hitherto been scientifically examined, nor do they appear to have suffered damage apart from ploughing. The excavation here described was undertaken by the Archaeological Section of the Cardiff Naturalists' Society in the hope that from it might be derived definite information bearing upon the intensive Bronze Age occupation of this part of the coastal plain which the barrows clearly attest.

INVESTIGATION OF THE INTERNAL STRUCTURE AND EVOLUTION OF THE HOLOCENE BARRIER OF MARICÁ (RIO DE JANEIRO)

2016 ◽  
Vol 33 (3) ◽  
Author(s):  
Carolina Pereira Silvestre ◽  
André Luiz Carvalho da Silva ◽  
Maria Augusta Martins da Silva ◽  
Amilsom Rangel Rodrigues
Keyword(s):  
Internal Structure ◽  
Coastal Plain ◽  
Rio De Janeiro ◽  
The Holocene

ABSTRACT. The objective of this study is the identification of the internal structure of the Holocene barrier of the Maricá coastal plain (Rio de Janeiro) for the understanding of the... RESUMO. O presente estudo objetivou identificar a estrutura interna da barreira holocênica buscando compreender a evolução da planície costeira de Maricá (Rio de Janeiro). A geomorfologia regional...

LATE QUATERNARY SEA-LEVEL HIGHSTANDS OF THE MID-ATLANTIC US COASTAL PLAIN AND SUB-ORBITAL VARIABILITY WITH IMPLICATIONS FOR ICE SHEET SENSITIVITY

2016 ◽  
Author(s):  
Robert K. Poirier ◽  
◽  
Thomas M. Cronin ◽  
Thomas M. Cronin ◽  
Miriam E. Katz ◽  
...  
Keyword(s):  
Sea Level ◽  
Coastal Plain ◽  
Late Quaternary ◽  
Ice Sheet
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