Mineralogy of ferromanganese weathering crusts from Codru Moma Mountains (Romania)

2021 ◽  
Vol 197 (1) ◽  
pp. 85-103
Author(s):  
Emilia Mosonyi ◽  
Lucreţia Ghergari † ◽  
Ioan Mârza
Keyword(s):  
Weathering Crusts

Evaluation of computer-controlled SEM in the study of metal-contaminated soils

2003 ◽  
Vol 67 (2) ◽  
pp. 219-231 ◽  
Author(s):  
H. W. Langmi ◽  
J. Watt
Keyword(s):  
Electron Microscopy ◽  
Heavy Metals ◽  
Contaminated Soils ◽  
X Ray ◽  
Computer Controlled ◽  
Weathering Crusts ◽  
Individual Particles ◽  
Element Mapping ◽  
Scanning Electron

Computer-controlled scanning electron microscopy (CCSEM) has been assessed for the determination of form and size distribution of heavy metals in urban contaminated soils. Metal distributions within individual particles were determined using X-ray element mapping. The sites selected for study were (1) around a landfill site, previously a colliery in Wolverhampton, UK and (2) a private garden adjacent to a railway in Nottingham, UK. Backscattered thresholding techniques were used to isolate the Pb-containing categories. The classification results for both Wolverhampton and Nottingham soils were generally similar but more Pb-containing classes were observed for the Nottingham samples when a comparison was made between results of the same size fractions. However, difficulties with the technique arose when particles showing chemically similar weathering crusts were assigned to the same class, despite having different internal compositions. The CCSEM data therefore need to be interpreted with caution and their application limited to situations in which particle internal complexity is not an issue.

scholarly journals Unique Ultra-Rich Rare Metal Ores of the Tomtor Complex and Problem of Their Genesis

2019 ◽  
Vol 5 ◽  
pp. 70-88
Author(s):  
A.V. Lapin ◽  
A.V. Tolstov ◽  
I.M. Kulikova
Keyword(s):  
Mineral Composition ◽  
Rare Metal ◽  
Genetic Models ◽  
Textural Features ◽  
Weathering Crusts ◽  
Geologic Setting

Main genetic models of the formation of ultra-rich rare metal ores of the Tomtor deposit (Yakutia) are compared on the basis of their structural-textural features, mineral composition, and geologic setting: 1) reducing epigenesis of laterite weathering crusts of carbonatites and 2) redeposition of weathering products of carbonatites. It is shown that the unique features of the Tomtor deposit are explained by more complex (compared with other deposits of weathering crusts of carbonatites) evolution, which is expressed in two consecutive stages of supergenesis: laterite weathering and reducing epigenesis and their total ore-concentrating efects. The searching-forecast criteria for ores of the Tomtor type are suggested on the basis of epigenetic model of their formation.

Multicellular algae from lower Proterozoic (2.45 Ga) weathering crusts of the Kola Peninsula

2011 ◽  
Author(s):  
Marina M. Astafieva ◽  
Alexei Y. Rozanov ◽  
Richard B. Hoover
Keyword(s):  
Kola Peninsula ◽  
Lower Proterozoic ◽  
Weathering Crusts

Iron in the kaolinites from kaolin and bauxite weathering crusts after granites: EPR data

2008 ◽  
Vol 423 (2) ◽  
pp. 1488-1491 ◽  
Author(s):  
N. S. Bortnikov ◽  
R. M. Mineeva ◽  
V. M. Novikov ◽  
B. F. Gorbachev ◽  
A. V. Speransky
Keyword(s):  
Weathering Crusts
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