Environmental magnetism evidence for longshore drift distribution of Fe-bearing phases: An example from the Brazilian southeastern coastal region

2021 ◽  
Vol 91 (11) ◽  
pp. 1133-1150
Author(s):  
Vitor E.P. Silveira ◽  
Natália B. dos Santos ◽  
Daniel R. Franco ◽  
Emanuele F. la Terra ◽  
Joshua M. Feinberg ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Coastal Area ◽  
Rio De Janeiro ◽  
High Energy ◽  
Heavy Mineral ◽  
Heavy Minerals ◽  
Northern Coast ◽  
Mineral Distribution ◽  
Longshore Drift ◽  
Paraíba Do Sul River

ABSTRACT The accumulation of heavy minerals along a part of the southeastern Brazilian coast (northern coast of Rio de Janeiro State, Brazil) provides insight into sedimentary provenance and transport by longshore drift. In particular, recent work has focused on heavy minerals as tracers to determine sedimentary sources and transport pathways, indicating a mineral distribution according to the northward and southward coastal transport cells. There is also evidence of heavy-mineral transport by the Paraíba do Sul River. However, research has not been done in this area on the opaque fraction (iron oxides and oxyhydroxides), which are good tracers for provenance and distribution processes. Here we intend to: 1) characterize the spatial variation of the magnetic properties of heavy-mineral contents throughout a coastal area of the Itabapoana and Paraíba do Sul River mouths (state of Rio de Janeiro), 2) evaluate the contribution of coastal dynamics on the mineral distribution along this coastal area, 3) provide contributions on the provenance of iron-bearing minerals. Results indicate that a bimodal pattern was observed for the magnetic remanence of magnetite and hematite near the Paraíba do Sul River. For the northernmost section, goethite exhibits a gradual increase in concentration towards the central part of the study area. Additionally, higher heavy-mineral content is observed at the northern coastal section, which may be related to coastal morphology, which is exposed to high-energy beach processes. It is possible to verify three sampling groups in accordance with their magnetic properties: 1) the “southernmost” and 2) the “northernmost” groups, suggesting a mineral provenance related to the Paraíba do Sul and Itabapoana rivers, respectively, as possible major sources, and 3) another at the intermediate section of the area, possibly linked to the erosion of the Barreiras Formation bluffs. Results also show a correspondence between the variability of magnetic parameters and the main directions of the coastal transport cells.

scholarly journals Heavy Mineral Distribution in the Lokoja and Patti Formations, Southern Bida Basin, Nigeria: Implications for Provenance, Maturity and Transport History

2020 ◽  
Vol 66 (3) ◽  
pp. 185-197
Author(s):  
S. I. Bankole ◽  
A. Akinmosin ◽  
T. Omeru ◽  
H. E. Ibrahim
Keyword(s):  
Source Rock ◽  
Chemical Weathering ◽  
Crystalline Rock ◽  
Heavy Mineral ◽  
Heavy Minerals ◽  
Mineral Component ◽  
Mineral Distribution ◽  
Textural Characteristics

AbstractHeavy mineral component of 13 samples from the Lokoja and Patti Formations, Bida Basin have been studied for their textural characteristics, compositional abundance, maturity and provenance determinations. The suite of heavy minerals encountered is classified as opaque and non-opaque constituents. The non-opaque components include zircon, tourmaline, rutile, garnet, staurolite, epidote, kyanite, titanite, lawsonite, cassiterite, sillimanite, hornblende, hypersthene and andalusite. The assemblage is generally dominated by zircon and tourmaline in the two formations. The constituent heavy minerals identified are dominated by ultra-stable and stable classes, whereas the ZTR indices indicate mineralogical immaturity coupled with textural immaturity of the constituent grains. This suggests the possible dominance of chemical weathering of the source rock. The suites of minerals recovered have been linked to both metamorphic and non-metamorphic crystalline rock origins.

scholarly journals Palynological evidence of the replacement of the hygrophilous forest by field vegetation during the last 7,000 years B.P. in the northern coast of Rio de Janeiro, Brazil

2011 ◽  
Vol 83 (3) ◽  
pp. 939-952 ◽  
Author(s):  
Cynthia F.P. da Luz ◽  
Ortrud M. Barth ◽  
Louis Martin ◽  
Cleverson G. Silva ◽  
Bruno J. Turcq
Keyword(s):  
Coastal Plain ◽  
Rio De Janeiro ◽  
Partial Replacement ◽  
First Episode ◽  
Northern Coast ◽  
Palynological Analysis ◽  
Indigenous Groups ◽  
Lake Cores ◽  
Janeiro State ◽  
Paraíba Do Sul River

Historians claim that European colonizers of the northern coast of Rio de Janeiro State found vast herbaceous fields when arrived in this region. Hypotheses about the origin of these fields include forest burning by the Goitacás indians and periodical floods by the Paraíba do Sul River and the lagoon system. The palynologycal analysis of two lake cores obtained in the municipality of Campos dos Goytacazes revealed opening episodes of hygrophilous forest and the establishment of field vegetation, recorded at ca. 6,500 and ca. 4,000 14C yr BP. The partial replacement of forest by field vegetation in the first episode was probably caused by floods of the lower areas during the development of the Holocene lagoon phase. During the second episode, successions of vegetational patterns occurred due to lowering of the sea level. Drying and enlarging of the coastal plain have allowed its colonization by herbs and heliophyte plants. The palynological analysis does not provide any evidence that sustains the theories of use of fire and agricultural activities by indigenous groups during these periods.

scholarly journals The Occurences of Heavy Mineral Placer at Kendawangan and Its Surrounding, West Kalimantan Province

2017 ◽  
Vol 32 (1) ◽  
Author(s):  
Agus Setyanto ◽  
Maman Surachman
Keyword(s):  
Heavy Metals ◽  
Coastal Area ◽  
Heavy Mineral ◽  
Heavy Minerals ◽  
Surrounding Area ◽  
West Kalimantan ◽  
Sediment Samples

The main objective of this study is to identify and to determine the variation and content of heavy mineral placer of Kendawangan coastal, offshore and its surrounding area. Sediment samples were taken from 18 locations, such as 12 samples from offshore and 6 samples from coastal area. For this analysis the heavy metals were identified and analyzed using isodynamic separator and binocular microscopic. The result indicates that heavy minerals consist of zircon, cassiterite, rutile, ilmenite, topaz, chalcopyrite, epidote, pyrite, hematite, hornblende and magnetite. Cassiterite and zircon are also found in sediment samples in all locations and potentially to be further developed. Keywords: Heavy minerals placer, Zircon, Cassiterite, Kendawangan, West Kalimantan Tujuan penelitian ini adalah untuk mengidentifikasi dan menentukan variasi kandungan mineral berat plaser pada sedimen pantai dan lepas pantai Kendawangan dan sekitarnya. Sampel sedimen diambil dari 18 lokasi yang terdiri atas 12 sampel sedimen lepas pantai dan 6 sampel sedimen pantai. Analisis dilakukan dengan menggunakan isodinamik separator dan mikroskop binokular. Hasil analisis menunjukkan bahwa mineral berat terdiri atas zircon, kasiterit, rutil, ilmenit, topas, kalkopirit, epidot, pirit, hematit, hornblende, dan magnetit. Kasiterit dan zircon juga dijumpai pada sampel sedimen di semua lokasi yang dianalisis dan berpotensi untuk dikembangkan lebih lanjut. Kata kunci: Mineral berat plaser, Zirkon, Kasiterit, Kendawangan, Kalimantan Barat

scholarly journals Development of the Narva-Jõesuu beach, mineral composition of beach deposits and destruction of the pier, southeastern coast of the Gulf of Finland

2019 ◽  
Vol 11 (1) ◽  
pp. 961-968
Author(s):  
Johanna-Iisebel Järvelill
Keyword(s):  
Mineral Composition ◽  
Mineral Content ◽  
Sandy Beach ◽  
Heavy Minerals ◽  
Gulf Of Finland ◽  
Immersion Method ◽  
Southeastern Coast ◽  
Longshore Drift ◽  
Favorable Conditions ◽  
The Gulf Of Finland

Abstract Narva-Jõesuu lies at the eastern southeastern coast of the Gulf of Finland, at the Estonian and Russian border. The beach is influenced by heavy winds, waves and drift ice attacks, which are seriously changing the beach. It is the longest sandy beach in Estonia and longshore drift on this beach has induced favorable conditions for the separation of heavy minerals. The aims of the study were to describe the development of the coast, discuss the influence of the destructed pier, and to identify the mineral composition of beach sands. The dynamics of the coast were mainly through comparison with older topographic maps (from the beginning of the 20th century). For mineral analysis the immersion method was applied. The heavy mineral content was found to increase from east to west. The pier was built in Narva-Jõesuu in 1987/88 for protecting the coast, but it is now broken. Consequently, storms are crashing against the coast and erosion of the sandy shore has started. Therefore, the pier should be restored to avoid further beach destruction.

scholarly journals Magnetic properties and crystal structure of elemental cobalt powder modified by high-energy ball milling

2019 ◽  
Vol 8 (5) ◽  
pp. 4995-5003 ◽  
Author(s):  
J.A. Betancourt-Cantera ◽  
F. Sánchez-De Jesús ◽  
A.M. Bolarín-Miró ◽  
G. Torres-Villaseñor ◽  
L.G. Betancourt-Cantera
Keyword(s):  
Crystal Structure ◽  
Magnetic Properties ◽  
Ball Milling ◽  
High Energy ◽  
High Energy Ball Milling ◽  
Cobalt Powder ◽  
Energy Ball

scholarly journals Magnetic properties of iron nitride-alumina nanocomposite materials prepared by high-energy ball milling

2003 ◽  
Vol 24 (1-3) ◽  
pp. 93-96 ◽  
Author(s):  
S. R. Mishra ◽  
G. J. Long ◽  
F. Grandjean ◽  
R. P. Hermann ◽  
S. Roy ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Ball Milling ◽  
High Energy ◽  
Nanocomposite Materials ◽  
High Energy Ball Milling ◽  
Iron Nitride ◽  
Energy Ball

Effect of Nitridation Magnetic Properties of Nanocrystalline Fe-Co Alloy Powders

2010 ◽  
Vol 654-656 ◽  
pp. 1106-1109
Author(s):  
Ya Qiong He ◽  
Chang Hui Mao ◽  
Jian Yang
Keyword(s):  
Grain Size ◽  
Magnetic Properties ◽  
Alloy Powder ◽  
High Energy ◽  
X Ray Diffraction ◽  
Powder Mixtures ◽  
X Ray ◽  
Transmission Electron ◽  
Nitridation Temperature ◽  
Microstructure And Magnetic Properties

Nanocrystalline Fe-Co alloy powders, which were prepared by high-energy mechanical milling, were nitrided under the mixing gas of NH3/H2 in the temperature range from 380°C to 510°C. X-ray diffraction (XRD) was used to analyze the grain size and reaction during the processing. The magnetic properties of the nitrided powders were measured by Vibrating Sample Magnetometer (VSM). The results show that with the appearance of Fe4N phase after nitride treatment, and the grain-size of FeCo phase decreases with the increase of nitridation temperature between 380°C to 450°C.The saturation magnetization of nitrided alloy powder treated at 480°C is about 18% higher than that of the initial Fe-Co alloy powder, accompanied by the reduction of the coercivity. Transmission electron microscope (TEM) was used, attempting to further analyze the effect of Fe4N phase on microstructure and magnetic properties of the powder mixtures.

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