Salt marsh palynological assemblages as modern analogue tools for interpreting past vegetation zones and environmental conditions in the NE coastal plain of Argentina

2021 ◽  
Vol 106 ◽  
pp. 103025
Author(s):  
Mariel S. Luengo ◽  
Isabel Vilanova ◽  
M. Florencia Pisano ◽  
Gabriela D'Amico ◽  
Nicole Pommarés ◽  
...  
2019 ◽  
Vol 21 (2) ◽  
pp. 1217-1233
Author(s):  
Filipe Maciel De Moura ◽  
Antônio Rodrigues Ximenes Neto ◽  
Adryane Gorayeb ◽  
Davis Pereira De Paula ◽  
Fábio Perdigão Vasconcelos

A planície costeira brasileira, em especial a do Nordeste do Brasil, apresenta um sistema morfológico que sofre diversas pressões do ponto de vista do uso e ocupação dos seus espaços. Logo, o entendimento da dinâmica natural e espacial desse ambiente requer a adoção de metodologias que contemplem uma abordagem em múltiplas escalas. Neste sentido, este trabalho tem o intuito de analisar as múltiplas morfologias associadas a praia das Fontes, em Beberibe-CE, em diferentes escalas taxonômicas. Esta análise auxiliou na realização de um prognostico das condições ambientais e de sua capacidade de suporte. Metodologicamente aplicou-se a proposta de Bertrand (1971), adotando-se apenas as unidades inferiores que inclui os níveis taxonômicos regionais e/ou locais, compreendendo os geossistemas, geofáciese os geótopos. Os resultados alcançados foram satisfatórios, uma vez que as unidades mapeadas foram validadas em atividades de campo para reconhecimento do produto cartográfico.Palavras-chave: Análise Multiescalar. Geomorfologia Costeira. Formação Barreiras. ABSTRACTThe Brazilian coastal plain, especially in the Northeast of Brazil, presents a morphological system that undergoes several pressures from the point of view of the use and occupation of its spaces. Therefore, the understanding of the natural and spatial dynamics of this environment requires the adoption of methodologies that contemplate a multi-scale approach. In this sense, this work has the purpose of analyzing the multiple morphologies associated to Praia das Fontes, in Beberibe-CE, at different taxonomic scales. This analysis assisted in the accomplishment of a prognosis of the environmental conditions and their support capacity. Methodologically Bertrand's (1972) proposal was applied, adopting only the lower units that includes regional and / or local taxonomic levels, including geosystems, geophysics and geo-objects. The results were satisfactory, since the mapped units were validated in field activities to recognize the cartographic product.Keywords: Multiscalar Analysis. Coastal Geomorphology. Training Barriers. RESUMENLa llanura costera brasileña, especialmente en el noreste de Brasil, tiene un sistema morfológico que sufre varias presiones desde el punto de vista del uso y la ocupación de sus espacios. Por lo tanto, comprender la dinámica natural y espacial de este entorno requiere la adopción de metodologías que incluyan un enfoque de múltiples escalas. En este sentido, este trabajo tiene como objetivo analizar las múltiples morfologías asociadas a la playa de Fontes, en Beberibe-CE, en diferentes escalas taxonómicas. Este análisis ayudó a hacer una predicción de las condiciones ambientales y su capacidad de carga. Metodológicamente, se aplicó la propuesta de Bertrand (1971), adoptando solo las unidades inferiores, que incluyen niveles taxonómicos regionales y / o locales, incluidos los geosistemas, geofacies y geotopos. Los resultados obtenidos fueron satisfactorios, ya que las unidades mapeadas fueron validadas en actividades de campo para el reconocimiento de productos cartográficos.Palabras clave: Análisis multiescala. Geomorfología costera. Barreras de entrenamiento.


2021 ◽  
Vol 9 ◽  
Author(s):  
Grace D. Molino ◽  
Zafer Defne ◽  
Alfredo L. Aretxabaleta ◽  
Neil K. Ganju ◽  
Joel A. Carr

Coastal salt marshes, which provide valuable ecosystem services such as flood mitigation and carbon sequestration, are threatened by rising sea level. In response, these ecosystems migrate landward, converting available upland into salt marsh. In the coastal-plain surrounding Chesapeake Bay, United States, conversion of coastal forest to salt marsh is well-documented and may offset salt marsh loss due to sea level rise, sediment deficits, and wave erosion. Land slope at the marsh-forest boundary is an important factor determining migration likelihood, however, the standard method of using field measurements to assess slope across the marsh-forest boundary is impractical on the scale of an estuary. Therefore, we developed a general slope quantification method that uses high resolution elevation data and a repurposed shoreline analysis tool to determine slope along the marsh-forest boundary for the entire Chesapeake Bay coastal-plain and find that less than 3% of transects have a slope value less than 1%; these low slope environments offer more favorable conditions for forest to marsh conversion. Then, we combine the bay-wide slope and elevation data with inundation modeling from Hurricane Isabel to determine likelihood of coastal forest conversion to salt marsh. This method can be applied to local and estuary-scale research to support management decisions regarding which upland forested areas are more critical to preserve as available space for marsh migration.


1996 ◽  
Vol 36 (1) ◽  
pp. 269 ◽  
Author(s):  
P.A. Arditto

This paper presents the results and conclusions of an integrated sequence stratigraphic study of the Callovian marine succession across area 'A' of the Zone of Cooperation (ZOCA). This study utilised wireline log and conventional core data from within ZOCA 91–1 and ZOCA 91–12, and incorporated trade data from adjacent permits, to generate a rational depositional model for the succession. Three distinct third-order sequences have been recognised from the detailed correlation of regional flooding surfaces recognised on wireline log motifs calibrated against conventional core and biostratigraphy. The base of the oldest third-order sequence includes section previously referred to as Plover Formation, and roughly corresponds to the W.digitata/W.indotata zone boundary. The Callovian Unconformity within the ZOCA region is thus relegated to a third-order sequence boundary or disconformity. The term Elang Formation is proposed for this Callovian succession which comprises three third-order sequences mappable across ZOCA. The well-type section for the Elang Formation is Elang-1, and an additional well reference section would be Elang-2, as both these wells contain significant and complementary cored section.Detailed sedimentological studies on conventional core reveal that the Elang Formation comprises a succession of coastal plain to nearshore marine sediments, ranging from low sinuosity fluvial channel, fluvial-dominated deltaic, proximal low sinuosity estuarine channel and distal outer bay sediments. Only minor wave-dominated, open marine shoref ace intervals were interpreted, most of the cored intervals indicating a fluvially-domi-nated shoreline with minimal wave reworking. Isopach and per cent sand maps generated for each third-order sequence comprising the Elang Formation illustrate the successive sediment distribution patterns across ZOCA during the progressive marine transgression from the top of the fluvio-deltaic Plover Formation to the base of the offshore marine Lower Flamingo Group. The sand-trend maps for the three sequences which comprise the Elang Formation indicate a fluvial/estuarine-dominated delta system, sourced from the region of the Laminaria Field, AC/P8, building east and southeast out across the ZOCA region. A modern analogue of this delta system in both size and sedimentation style may be the Brahmaputra/Ganges Delta of East Bengal.


2013 ◽  
Vol 36 (3) ◽  
pp. 654-664 ◽  
Author(s):  
Kerstin Wasson ◽  
Andrea Woolfolk ◽  
Carla Fresquez

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