scholarly journals The Barreiras Group in the Northeastern coast of the State of Bahia, Brazil: depositional mechanisms and processes

2001 ◽  
Vol 73 (3) ◽  
pp. 417-427 ◽  
Author(s):  
GERALDO S. VILAS BÔAS ◽  
FLÁVIO J. SAMPAIO ◽  
ANTONIO M. S. PEREIRA
Keyword(s):  
Debris Flows ◽  
The State ◽  
Brazilian Coast ◽  
Alluvial Fans ◽  
Climate Control ◽  
Fluvial Systems ◽  
Lower Pleistocene ◽  
Basal Portion ◽  
Sedimentary Deposit ◽  
Sandy Sediments

The Barreiras Group is a Miocene to Lower Pleistocene continental terrigenous sedimentary deposit exhibiting a large occurrence along the Brazilian coast. In the Conde region, located in the northeastern part of the State of Bahia, the sedimentological characteristics of these sediments are indicative of a deposition as gravelly and sandy bed load in braided fluvial systems, related to alluvial fans, under an arid to semi-arid climate. The basal portion of the group is dominated by a gravelly-sandy lithofacies deposited by debris flows and pseudoplastic debris flows, with lesser occurrences of subaqueous deposits, characterizing a proximal fluvial system deposition. The upper portion is made up of gravelly-sandy sediments that include subaqueous, debris flows and pseudoplastic debris flows deposits. They suggest deposition in a more distal zone as indicated by the larger occurrence of subaqueous deposits and the presence, though rare, of downstream-accretion macroforms. Besides the climate control, deposition of the Barreiras Group was strongly influenced by the intraplate tectonism, which has been affecting the South America Platform since the Middle Miocene, when neotectonism began in Brazil.

scholarly journals Three new species of Scissurellidae (Gastropoda, Prosobranchia) from the coast of Brazil

1972 ◽  
Vol 21 (0) ◽  
pp. 01-13 ◽  
Author(s):  
Pierre Ch. Montouchet
Keyword(s):  
New Species ◽  
Sao Paulo ◽  
The State ◽  
Shallow Waters ◽  
Brazilian Coast ◽  
São Paulo ◽  
Internal Anatomy ◽  
The Third ◽  
Deep Waters ◽  
Three New Species

A consultation of the original descriptions of the genera of Scissurellidae led the author to conclude that the valid names for the genera of this family are: Scissurella d'Orbigny, 1823 (redescription by Sowerby, 1824), Anatoma Woodward, 1859, Inoisura Hedley, 1904, Scissurona Iredale, 1924, Sinezona Finlay, 1927. Scissurella and Anatoma are cosmopolites, the first generally living in shallow waters, associated to sea-weeds, while the second is found in deep waters. The three last genera are restricted to Australasia. Three new species are described from the Brazilian coast: Soissu rella alexandrei, Scissurella eleotilis and Scissurella morretesi. The internal anatomy of S. alexandrei is described. These three new species have been found in littoral shallow waters, the two first on the northeast Brazilian coast, the third on the coast of the State of São Paulo. The fourth known species of Scissurellidae from Brazil, Anatoma aedonia (Watson, 1886), was dredged by H.M.S, "Challenger", in 1873, off Pernambuco, 350 fm (640 m).

scholarly journals Fisionomias das Restingas do Delta do Parnaíba, Nordeste, Brasil (Faces of the Salt Marshes of Delta Parnaíba, Norteastern Brasil)

2011 ◽  
Vol 3 (3) ◽  
pp. 218 ◽  
Author(s):  
Francisco Soares Santos-Filho ◽  
Eduardo Bezerra de Almeida Jr. ◽  
Caio J. dos Reis Santos Soares ◽  
Carmen Silvia Zickel
Keyword(s):  
Environmental Protection ◽  
Salt Marshes ◽  
The State ◽  
River Delta ◽  
Coastal Vegetation ◽  
Brazilian Coast ◽  
Frequent Species ◽  
Concise Description

O presente trabalho traz uma caracterização das restingas da Área de Preservação Ambiental do Delta do Parnaíba, litoral do Piauí, Nordeste do Brasil. Foram estudadas e georreferenciadas as formações vegetais das áreas assentadas sobre solos Quaternários. Foram identificados os três tipos de fisionomias também presentes em outras restingas de diferentes regiões do litoral brasileiro, assim como os subtipos mais freqüentes. Além de uma concisa descrição das fisionomias encontradas no local, o trabalho traz uma lista das espécies mais freqüentes que predominam nestas paisagens.Palavras-Chave: Restingas – Fisionomia da vegetação – Área de Preservação Ambiental do Delta do Parnaíba.  Faces of the Salt Marshes of Delta Parnaíba, Norteastern Brasil   ABSTRACT This paper attempts to characterize ";;;;;;;;;;;;;Restinga";;;;;;;;;;;;; (coastal vegetation) located at EPAs (Environmental Protection Areas) in the Parnaiba river delta by the coast of the state of Piauí, in the northeast of Brazil. Vegetation forms in areas over on soils of the Quaternary age were studied and geographically-referenced. The three types of physiognomy were identified, these being the same types found at other ";;;;;;;;;;;;;Restinga";;;;;;;;;;;;; areas on the Brazilian coast, as well as the most frequent subtypes. Along with a concise description of the physiognomy found on the coast of Piauí, this paper also brings a list of the most frequent species that predominate in this landscape.  Keywords: Vegetal Physiognomy – Parnaiba River Delta Environmental Protection Areas.

Zooarchaeological evidence that the brown mussel (Perna perna) is a bioinvader of coastal Brazil

The Holocene ◽  
2018 ◽  
Vol 28 (11) ◽  
pp. 1771-1780 ◽  
Author(s):  
Edson P Silva ◽  
Rosa CCL Souza ◽  
Tania A Lima ◽  
Flávio C Fernandes ◽  
Kita D Macario ◽  
...  
Keyword(s):  
Native Species ◽  
Radiocarbon Dating ◽  
The State ◽  
Colonial Period ◽  
The Other ◽  
Brazilian Coast ◽  
Perna Perna ◽  
Great Probability ◽  
Haplotypic Diversity ◽  
Brazilian Populations

Interactions between invader species and the local biota may lead to disequilibria in regional ecosystems. For such reason, the cultivation of nonnative species may be prohibited in specific regions, as a means of protecting native species. On the other hand, the question of whether a species is a bioinvader or not may not be straightforward. This is the case of the mollusc Perna perna, presently naturalized and widely distributed along Brazilian coast, from the Bay of Vitória, in the state of Espírito Santo (ES), to the state of Rio Grande do Sul (RS). Following previous works that explored the hypothesis that P. perna invaded the coast of Brazil at the colonial period, attached to slave ships, we discuss zooarchaeological data, radiocarbon dating, and molecular genetics analyses. Out of the 578 archeological shellmounds investigated, 542 (93.8%) had no records of P. perna. From the radiocarbon dating results, it is possible to infer that the presence of the two P. perna specimens from the Saquarema shellmound, in Rio de Janeiro, as well as the other shells from the top layer, is likely related to a recent occupation of the site in the colonial period, with a great probability of being from the XVII or XVIII centuries. Data on genetic population structure of P. perna along the Brazilian coast showed higher genetic identities between the African and the Brazilian populations than among the Brazilian populations, while haplotypic diversity shows a pattern which relates to trade routes of slaves (XVII and XVIII centuries) between Africa and Brazil. These data reinforce the argument that the appearance of P. perna along the Brazilian coast is due to invasion during historical time.

scholarly journals Hydrogeomorphic processes and torrent control works on a large alluvial fan in the eastern Italian Alps

2010 ◽  
Vol 10 (3) ◽  
pp. 547-558 ◽  
Author(s):  
L. Marchi ◽  
M. Cavalli ◽  
V. D'Agostino
Keyword(s):  
Urban Areas ◽  
Debris Flows ◽  
Land Use Changes ◽  
Integrated Approach ◽  
Alluvial Fan ◽  
Aerial Photographs ◽  
European Alps ◽  
Alluvial Fans ◽  
Economic Activities ◽  
Hazard Management

Abstract. Alluvial fans are often present at the outlet of small drainage basins in alpine valleys; their formation is due to sediment transport associated with flash floods and debris flows. Alluvial fans are preferred sites for human settlements and are frequently crossed by transport routes. In order to reduce the risk for economic activities located on or near the fan and prevent loss of lives due to floods and debris flows, torrent control works have been extensively carried out on many alpine alluvial fans. Hazard management on alluvial fans in alpine regions is dependent upon reliable procedures to evaluate variations in the frequency and severity of hydrogeomorphic processes and the long-term performance of the torrent training works. An integrated approach to the analysis of hydrogeomorphic processes and their interactions with torrent control works has been applied to a large alluvial fan in the southern Carnic Alps (northeastern Italy). Study methods encompass field observations, interpretation of aerial photographs, analysis of historical documents, and numerical modelling of debris flows. The overall performance of control works implemented in the early decades of 20th century was satisfactory, and a reduction of hazardous events was recognised from features observed in the field and in aerial photographs, as well as from the analysis of historical records. The 2-D simulation of debris flows confirms these findings, indicating that debris flow deposition would not affect urban areas or main roads, even in the case of a high-magnitude event. Present issues in the management of the studied alluvial fan are representative of situations frequently found in the European Alps and deal with the need for maintenance of the control structures and the pressures for land use changes aimed at the economic exploitation of the fan surface.

Tributary-junction alluvial fan response to an ENSO rainfall event in the El Huasco watershed, northern Chile

2020 ◽  
Vol 44 (5) ◽  
pp. 679-699 ◽  
Author(s):  
Albert Cabré ◽  
Germán Aguilar ◽  
Anne E. Mather ◽  
Víctor Fredes ◽  
Rodrigo Riquelme
Keyword(s):  
Debris Flows ◽  
Alluvial Fan ◽  
Storm Event ◽  
Arid Zones ◽  
Alluvial Fans ◽  
Main Trunk ◽  
Extreme Rainfall Events ◽  
Rainfall Events ◽  
Main River ◽  
Longitudinal Connectivity

Tributary-junction alluvial fans situated at the intersection of confined valleys with <100 km2 tributary catchments are of special interest to evaluate the heterogeneous consequences of extreme rainfall events in arid zones. These fans record the episodic sedimentological behaviour of the hillslope response to rainstorm events within tributary catchments, together with the influence on the main fluvial systems. In this paper, we benefit from the March 2015 event (23–26 March 2015), which produced 75–46 mm of precipitation over four days in the southern portion of the Atacama Desert. This storm event triggered several debris flows in El Huasco River watershed tributaries and, therefore, tributary-junction alluvial fans received a total of ∼106 m3 of sediments across 49 activated catchments. We find that the characteristic storm signature across the catchments can be synthetised in a conceptual fan formation model based on field mapping of facies (F1 to F6) present in the fans. The characteristic signature is a record of initially high sediment-to-water flows restricted to the fan environments (mainly debris flows) followed by later, more dilute (mainly hyper-concentrated to fluvial) flows that incise the tributary-junction alluvial fan deposits and link tributary catchments with the main river. These later-stage flood event deposits, locally, are capable of ponding and compartmentalising the main river where the longitudinal connectivity of the tributary-junction catchment is effective. This situation improves tributary-junction fan slope and main-trunk-channel linkages. This approach provides a reference framework for understanding the distribution and routing of effective runoff from similar rainfall events that control the aggradation and incision of the fluvial system, which is of great value when studying past stratigraphic arrangements in these arid alleys.

scholarly journals Amphibia, Anura, Cycloramphidae, Odontophrynus carvalhoi Savage and Cei, 1965: distribution extension and geographic distribution map

Check List ◽  
2010 ◽  
Vol 6 (4) ◽  
pp. 493 ◽  
Author(s):  
Barnagleison Silva Lisboa ◽  
Ubiratan Gonçalves da Silva ◽  
Célio Fernando Baptista Haddad
Keyword(s):  
Geographic Distribution ◽  
New Record ◽  
First Record ◽  
The State ◽  
Brazilian Coast ◽  
Distribution Map

We present the first record of Odontophrynus carvalhoi for the state of Alagoas, Brazil, and a distribution map for this species. This new record represents the nearest location to the Brazilian coast known for this species.

scholarly journals First record of Phragmatopoma caudata Krøyer in Mörch, 1863 (Annelida, Sabellariidae) in the state of Piauí, northern Brazilian coast: westernmost record in Brazil

Check List ◽  
2017 ◽  
Vol 13 (4) ◽  
pp. 343-348
Author(s):  
José Gerardo Ferreira Gomes Filho ◽  
Marcus V. Quixabeira Bezerra dos Santos ◽  
Rosana Aquino de Souza
Keyword(s):  
First Record ◽  
The State ◽  
Brazilian Coast
Sign in / Sign up

Export Citation Format

Share Document