Magnetic susceptibility of the selenides of some yttrium-group rare-earth elements

ResumoO Gabro de Lídice corresponde a um corpo tabular, com cerca de 4,0 quilômetros de extensão e espessura entre 100 e 200 metros, constituído por hiperstênio, diopsídio, olivina, plagioclásio e minerais opacos (óxidos de Fe e Ti). Assinaturas petrográfica e geoquímica indicam caráter toleítico, entre os campos alcalino e subalcalino. O enriquecimento em V é de 2 a 3 vezes maior do que o clarck esperado para tal tipo de rocha. O principal óxido é a titanomagnetita, com inclusões e exsoluções de ilmenita. O vanádio concentra-se principalmente na titanomagnetita, variando os teores entre 0,68% e 2,07% de V2O5. Análises ICP-MS em pré-concentrado de titanomagnetita forneceram teores de 50,86% de Fe2O3t, 13,56% de TiO2 e 3.721 ppm de vanádio (~ 0,66% de V2O5). Quimicamente a ilmenita tem conteúdo em Fe2O3t (46,75% a 48,80%) e TiO2 (49,99% a 51,36%). Amostras enriquecidas em titanomagnetita exibem valores dos elementos terras raras e traço 30 vezes inferiores aos observados nas demais amostras. Ao longo de todo o corpo, a susceptibilidade magnética varia em escala centimétrica a decimétrica e está associada a concentrações anômalas de titanomagnetita na rocha, o que pode representar um bandamento magmático. Os dados apresentados sugerem uma origem associada a ambiente intraplaca.Palavras Chave: Gabro, titanomagnetita, ilmenita, titânio, vanádio.AbstractFe-Ti-V ASSOCIATED WITH LIDICE GABBRO, RIO DE JANEIRO STATE. The Gabbro of Lidice has about 4.0 km in length and thickness between 100 and 200 meters, consisting of pyroxene, olivine, plagioclase and opaque minerals (Fe and Ti oxides). Petrographic and geochemical signatures indicate toleitic character, between the alkaline and subalcalino fields. Vanadium enrichment is from 2 to 3 times higher than the expected clarck for such rock. The main oxide is titanomagnetite, with inclusions and exsolutions of ilmenite. Vanadium (0,68% to 2,07% V2O5) is mainly concentrated in titanomagnetite. ICP-MS analyses in pre-concentrated of titanomagnetite provided levels of 50.86% of Fe2O3t, 13.56% of TiO2 and 3,721 ppm of vanadium (~ 0.66% de V2O5). Chemical analyses of ilmenite show content in Fe2O3t (from 46.75% to 48.80%) and TiO2 (from 49.99% to 51.36%). Samples enriched with titanomagnetite display values of trace and rare earth elements 30 times lower than those observed in other samples. Throughout the gabbro, the magnetic susceptibility varies from centimeter to decimeter scales and is associated with abnormal concentrations of titanomagnetite, which may represent magmatic banding. The data presented may suggest an origin associated with intraplate environment.Keywords: Gabbro, titanomagnetite, ilmenite, titanium, vanadium.

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Comparative analysis of soil magnetic susceptibility and concentration of rare earth elements in soil of problematic areas

Multidisciplinary Aspects of Production Engineering ◽

10.2478/mape-2019-0008 ◽

2019 ◽

Vol 2 (1) ◽

pp. 81-90

Author(s):

Jarosław Zawadzki ◽

Piotr Fabijańczyk

Keyword(s):

Magnetic Susceptibility ◽

Rare Earth ◽

Rare Earth Elements ◽

Coal Combustion ◽

Soil Samples ◽

Hard Coal ◽

Coal Seams ◽

Indirect Connection ◽

Ore Exploration ◽

Soil Magnetic Susceptibility

Abstract Soil contamination with rare earth metals (REE) can have both direct and indirect connection with industrial activity and ore-exploration. In the studies conducted so far, the presence of rare earth elements in coal seams, coal combustion waste as well as fly ash was found. It is important that detailed studies of the REE content in soil were not carried out in Poland. Until now, in a few studies, a high content of cerium and lanthanum was found in relation to the average content of the torn ones in the world. This work focuses on the areas under the influence of the industry associated with the extraction and combustion of hard coal, but also with other types of industry. Analyzes of REE content in soil were conducted in selected areas of the Upper Silesian Industrial Region and Norway, located near the Bjornevatn mine. In study areas, soil samples were collected and used for chemical and magnetometric measurements. Firstly, concentrations of REE were determined, and after that soil samples were used to measure soil magnetic susceptibility. Finally, statistical analyses were performed in order to check the correlation between REE concentrations in soil and soil magnetic susceptibility.

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Preparation and Crystal Structure of the Isotypic Carbides Ln3.67TC6 (Ln = rare earth elements; T = Mn, Fe, Ru) and Eu3,16NiC6

Zeitschrift für Naturforschung B ◽

10.1515/znb-1996-0214 ◽

1996 ◽

Vol 51 (2) ◽

pp. 249-256 ◽

Cited By ~ 21

Author(s):

Anne M. Witte ◽

Wolfgang Jeitschko

Keyword(s):

Crystal Structure ◽

Magnetic Susceptibility ◽

Rare Earth ◽

Rare Earth Elements ◽

Single Crystal ◽

Crystal Structures ◽

Variable Parameters ◽

X Ray ◽

Arc Melting ◽

Structure Factors

Abstract The 14 carbides Ln3.67MnC6 (Ln = La-Nd) and Ln3.67TC6 (Ln = La-Nd, Sm; T = Fe, Ru) were prepared from the elemental components by arc-melting and subsequent annealing. Eu3.16NiC6 was obtained from a lithium flux. The crystal structures of these nearly isotypic, hexagonal compounds (P63/m, Z = 2) were determined from single-crystal X-ray data; La3.67- FeC6: a = 878.7(2), c = 535.1(1) pm, R = 0.052 for 548 structure factors and 25 variable parameters; Eu3.16NiC6: a -860.0(1), c = 548.2(2) pm, R = 0.015 for 606 structure factors and 25 variables. The structures differ from the previously reported Gd3Mn2C6 structure by the occupancy of one manganese position by rare earth atoms. Since the lanthanum atoms are larger than the manganese atoms, only two thirds of these manganese positions can be occupied by the lanthanum atoms in La3.67FeC6. Eu3.16NiC6 has similar atomic positions. The C-C bond distances in the C2 pairs are 130(2) and 126.5(5) pm in the La and Eu compounds, respectively. Magnetic susceptibility measurements with a SQUID magnetometer indicate La3.67FeC6 to be Pauli paramagnetic. A test for superconductivity was negative down to 3 K.

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The northernmost marine Cretaceous–Tertiary boundary section: Nuussuaq, West Greenland

Geological Survey of Denmark and Greenland Bulletin ◽

10.34194/ggub.v180.5097 ◽

1998 ◽

pp. 138-144 ◽

Cited By ~ 2

Author(s):

Gregers Dam ◽

Henrik Nøhr-Hansen ◽

W. James Kennedy

Keyword(s):

Magnetic Susceptibility ◽

Rare Earth ◽

Rare Earth Elements ◽

Carbon Isotopes ◽

High Latitude ◽

North Coast ◽

West Greenland ◽

The North ◽

Northern Latitudes ◽

Northern High Latitude

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Dam, G., Nøhr-Hansen, H., & Keeennedy, W. J. (1998). The northernmost marine Cretaceous–Tertiary boundary section: Nuussuaq, West Greenland. Geology of Greenland Survey Bulletin, 180, 138-144. https://doi.org/10.34194/ggub.v180.5097 _______________ A new northern high-latitude Cretaceous–Tertiary (K–T) boundary section has been studied at Annertuneq on the north coast of Nuussuaq, central West Greenland (Fig. 1). This boundary section (Fig. 2) is the northernmost marine boundary section recognised so far (placed at palaeolatitude 58°N by Smith et al. 1981) and has been studied with respect to palynology, palaeontology, sedimentology, rare earth elements, magnetic susceptibility and carbon isotopes in order to describe and provide the context for the marine floristic changes across the K–T boundary in high northern latitudes (Nøhr-Hansen & Dam 1997; Kennedy et al. in press). The present paper is a summary of a research project on the K–T boundary section at Annertuneq, supported by the Carlsberg Foundation.

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