Journal ArticleDOI
Delivery and deposition of organic matter in surface sediments of Lagoa do Caçó (Brazil)
Abdelfettah Sifeddine,Philip A. Meyers,Renato Campello Cordeiro,Renato Campello Cordeiro,Renato Campello Cordeiro,Ana Luiza Spadano Albuquerque,Ana Luiza Spadano Albuquerque,Ana Luiza Spadano Albuquerque,Marcelo Bernardes,Marcelo Bernardes,Marcelo Bernardes,Bruno Turcq,Jorge Abrao,Jorge Abrao,Jorge Abrao +14 more
TLDR
The depth-related processes that affect the production and deposition of sedimentary organic matter in Lagoa do Caco (Brazil) were analyzed to identify the depthrelated processes as discussed by the authors.Abstract:
Elemental and isotopic compositions of organic matter in surficial sediments from five transects across Lagoa do Caco (Brazil) were analyzed to identify the depth-related processes that affect the production and deposition of sedimentary organic matter in this shallow tropical lake. Each of four transverse transects began at a margin dominated by aquatic macrophytes (Eleocharis), crossed the central deep part of the lake, and terminated in the opposite, macrophyte-dominated margin. In each transect, TOC concentrations, C/N ratios, and δ13C values decreased between 0 and 4 m, whereas δ15N values increased. The variables remained stable in sediment from 4 m water depth to the center of the lake at 10 m. The depth-related patterns reflect differences in both the delivery and the deposition of organic matter in the lake. Organic matter is produced in abundance in the marginal area by emersed and submerged macrophyte vegetation that diminishes with depth and disappears at 4 meters. After the disappearance of macrophytes, organic matter is produced at low rates principally by open-lake phytoplankton. Drawdown of dissolved oxygen is high in the lake margins, but it is low in the oligotrophic open waters of the lake. Preservation of organic matter is consequently better in sediments of the lake margins than in deep waters. The depth-related pattern of organic matter delivery and deposition in the sediments of Lagoa do Caco, in which water levels are sensitive to groundwater fluctuations, shows that the elemental and isotopic compositions of sediment organic matter can provide a record of changes in the paleohydrology of this and other similar shallow lake systems.read more
Citations
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The spatial distribution and sedimentary processes of organic matter in surface sediments of Nam Co, Central Tibetan Plateau
TL;DR: In this paper, 67 surface sediment samples collected from Nam Co in central Tibet were analyzed for total carbon, total organic carbon and total nitrogen, and 51 of these samples were also analyzed for n-alkanes.
Journal ArticleDOI
Use of multi-proxy approaches to determine the origin and depositional processes in modern lacustrine sediments: Carajás Plateau, Southeastern Amazon, Brazil
Prafulla Kumar Sahoo,Pedro Walfir M. Souza-Filho,José Tasso Felix Guimarães,Marcio Sousa da Silva,Francisco Costa,Carmem-Lara de Oliveira Manes,Douglas Oti,Renato Oliveira da Silva Júnior,Roberto Dall'Agnol +8 more
TL;DR: In this paper, the authors investigated the geochemical and isotopic compositions of surficial sediments from a plateau lake in Carajas, Southeastern Amazon region, to understand the spatial distribution of major and trace elements, δ13C, Δ15N, and C/N ratio, depositional processes, and the origin of inorganic and organic fractions.
Journal ArticleDOI
Spatial distribution and sources of organic carbon in the surface sediment of Bosten Lake, China
Zhitong Yu,Zhitong Yu,Xiujun Wang,Xiujun Wang,Xiujun Wang,Enlou Zhang,Chunhua Zhao,Xingqi Liu +7 more
TL;DR: In this paper, the authors collected 13 surface (0-2 cm) sediment samples in Bosten Lake and analyzed total organic carbon (TOC), total nitrogen (TN), stable carbon isotopic composition in TOC (δ13Corg), and grain size.
Journal ArticleDOI
Calibration of speleothem δ18O records against hydroclimate instrumental records in Central Brazil
Jean-Sébastien Moquet,Francisco W. Cruz,Valdir F. Novello,Nicolás Misailidis Stríkis,Michael Deininger,Ivo Karmann,R. Ventura Santos,Christian Millo,James Apaéstegui,Jean-Loup Guyot,A. Siffedine,Mathias Vuille,Hai Cheng,Hai Cheng,Richard Lawrence Edwards,William Santini +15 more
TL;DR: In this article, the authors calibrate the δ 18 O record of speleothems against historical precipitation and river discharge data in central Brazil, a region directly influenced by the Southern Atlantic Convergence Zone (SACZ), a major feature of the South American Monsoon System (SAMS).
Journal ArticleDOI
Petrographical and geochemical study of modern lacustrine sedimentary organic matter (Lagoa do Caçò, Maranão, Brazil): Relationship between early diagenesis, organic sedimentation and lacustrine filling
Mohammed Boussafir,Abdelfettah Sifeddine,Jérémy Jacob,Merouane Foudi,Renato Campello Cordeiro,Renato Campello Cordeiro,Ana Luiza Spadano Albuquerque,Ana Luiza Spadano Albuquerque,Jorge Abrao,Jorge Abrao,Bruno Turcq +10 more
TL;DR: In this paper, the results of organic petrographic and rock-Eval pyrolysis assessments of the biological origin and preservation state of the organic matter (OM) in modern sediments from two deep transects of the lake were presented.
References
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Journal ArticleDOI
The Late Pleistocene - Holocene palaeolimnology of Lake Victoria East Africa, based upon elemental and isotopic analyses of sedimentary organic matter
Michael R. Talbot,Tine Lærdal +1 more
TL;DR: In this article, three piston cores from Lake Victoria (East Africa) have been analysed for organic carbon (TOC) and nitrogen (TN) content, stable isotopes (δ13C and δ15N), and Hydrogen Index (HI).
Journal ArticleDOI
Hydrogen index and carbon isotopes of lacustrine organic matter as lake level indicators
TL;DR: In this article, optical and geochemical techniques were applied to organic matter of Late Quaternary sediments from Lakes Victoria and Rukwa, East Africa Variations in total organic carbon and hydrogen content (expressed as Hydrogen Index, HI) can be related to known changes in lake level and used to identify periods of very low water or subaerial exposure in basinal sequences.
Journal ArticleDOI
Relationship between C:N ratios of lake sediments, organic matter sources, and historical deforestation in Lake Pleasant, Massachusetts, USA
TL;DR: The C:N ratios of lake sediments may reflect proportions of terrestrial and algal carbon contributing to accumulation of sediment in Lake Pleasant, Massachussetts, USA which underwent watershed deforestation in about 1780 A.D as discussed by the authors.
Journal ArticleDOI
Palaeoclimatic changes deduced from 13C/12C and C/N ratios of Karewa lake sediments, India
TL;DR: In this article, the stable carbon isotope ratio, 13C/12C, and the elemental carbon to nitrogen (C/N) ratio of the organic fraction of the palaeomagnetically and radiometrically dated Pleistocene Karewa lake sediments from Kashmir, India, were reported.
Journal ArticleDOI
Variations in the stable isotope composition of aquatic plants and their implications for food web analysis
Paul I. Boon,Stuart E. Bunn +1 more
TL;DR: Significant temporal and spatial variations in the δ 13 C and δ 15 N values of aquatic plants collected from three small, lentic water bodies in south-eastern Australia are detected.