Chemical and mineralogical composition of fluvial sediments (Bistrita River, Romania): Geogenic vs. anthropogenic input into rivers on its way through mining areas

Geochemistry ◽  
2018 ◽  
Vol 78 (3) ◽  
pp. 385-395 ◽  
Author(s):  
Andreea Elena Maftei ◽  
Harald G. Dill ◽  
Andrei Buzatu ◽  
Ovidiu Gabriel Iancu ◽  
Nicolae Buzgar ◽  
...  
2020 ◽  
Vol 5 (1) ◽  
pp. 2
Author(s):  
Hemayatullah Ahmadi ◽  
Atal Yousufi ◽  
Amir Mohammad Mosazai

Sand is a common construction material used for various purposes, e.g., concrete, mortar, render, screed, and asphalt. The usage depends on its fineness, and its fineness is controlled by its mineralogical composition and physical-mechanical properties. This research aims to determine the chemical and mineralogical composition and the physical-mechanical properties of the Dasht-e-Taatrang Zar sand deposits within the Qarabagh and Bagram districts of Kabul and Parwan provinces in Afghanistan. To achieve the objectives of this research, a review of the existing literature has been combined with new extensive field works for macroscopic studies and sample collection, and laboratory analyses. In total, 23 samples during two phases of field works were collected and subjected to lab works for XRF, Schlich, and XRD analysis to determine the chemical and mineralogical composition; moreover, sieve and Atterberg analysis, specific gravity, soundness, and alkali-silica reaction tests were performed for characterization of the physical-mechanical properties of the studied samples. The results of the tests show that the Taatrang Zar sand deposits are considered as a suitable construction material, and due to their simple accessibility, the deposits have high potential as a construction material supplier for the Kabul new city project (Dehsabz) in Kabul and adjacent Parwan and Kapisa provinces.


Author(s):  
Igor Papish ◽  
Oleksii Telehuz

The article presents data on gross chemical and mineralogical composition of clay faction found in typical chernozems occurred within the Podillia Upland. Geographical regularities of formation as regards clayey profile of Chernozems pertaining to the same genetic series are revealed. The relationship between conditions and Chernozem development stage, character of vertical differentiation of basic mineral phases of clayey plasma and its chemical and mineralogical composition are shown. Izoclayey profile of hydromicas is the consequence of their relative accumulation as a result eluviation of colloid-dispersible mica-smectite minerals. The character of clay profile observed in Chernozems is determined by the correlation of intensity of carbonates leaching, lessivage and soils argillisation. Typical Podolian Chernozems are characterised with the like weathering crust of silicate type. The modern Chernozem clayey profile originated mainly during a wetter stage of soil formation. In the ploughable layer a high content of clastic minerals (quartz, potassium feldspar, sodium plagioclase) is observed. Random mixed and stratified mica-smectite minerals with a high content (>50 %) of smectite packets (33–63 %), hydromica (33–52 %), and kaolinite plus chlorite (4–15 %) are present in the profile. The mineralogical composition of soils clay fraction indicates obvious signs of smectite eluviation and relative illite accumulation. Clayey profile of the Bug upstream plateau located within the Podillia Upland is atypical for Chernozems found in the eastern forest-steppe and steppe areas. The distribution character of layered silicates, especially smectite, is even more contrastive. Clayey plasma redistributes differentially through leaching and lessivage processes. Accumulative type of sludge deposits formed in Chernozems of the Dniester plateau located within the Podillia Upland, even profile distribution of basic oxides and molar ratios of SiO2 : Al2O3 and SiO2 : Fe2O3 against the background of decreased downward smectite content indicate weakened eluviation of fine-grained clays towards the Dniester. The prevalence of smectite over hydromicas within the entire profile indicates argillisation of Chernozems. Key words: Chernozem, chemical-mineralogical composition, clayey minerals, hydromica, smectite, kaolinite, leaching, lessivage, argillisation.


1977 ◽  
Vol 39 ◽  
pp. 439-444
Author(s):  
E. R. D. Scott

On the basis of their chemical and mineralogical composition, 420 iron meteorites have been classified into 12 different groups. Each group seems to have come from a separate parent body. The largest group, IIIAB, probably formed an asteroidal core in a body approximately 100 km in radius, which was largely destroyed by collision 630 My ago. Another 67 analyzed irons do not belong to these groups, and may represent samples from another 20 or more bodies.


1993 ◽  
Vol 8 (4) ◽  
pp. 391-402 ◽  
Author(s):  
Luiz A. Martinelli ◽  
Reynaldo L. Victoria ◽  
Jose Luiz I. Dematte ◽  
J.E. Richey ◽  
A.H. Devol

Author(s):  
Barbara Kalisz ◽  
Paweł Sowiński ◽  
Mirosław Orzechowski ◽  
Sławomir Smólczyński ◽  
Jacek Długosz ◽  
...  

1887 ◽  
Vol 4 (11) ◽  
pp. 484-493 ◽  
Author(s):  
J. J. H. Teall

The term gneiss as generally used by geological writers signifies a rock of granitic composition in which a parallel structure in the arrangement of the constituents is more or less apparent. For our present purpose it is important to note that other plutonic rocks besides granite (e.g. diorite, gabbro, and peridotite) have their gneissose equivalents, so that, if we use the term gneiss in a structural rather than in a mineralogical sense, we may speak of diorite-gneiss, gabbro-gneiss, and so on. Now the parallel structure of gneissose rocks is of two kinds. It may consist (1) of a parallel arrangement of certain constituents (e.g. mica plates or porphyritic felspars), or (2) of an alternation of bands of varying chemical and mineralogical composition. It is agreed on all hands that a parallel structure of the first kind may be due either to the deformation of a mass of half-consolidated plutonic rock at the time of intrusion, in which case it is strictly analogous to the flow structure in many volcanic rocks, or to deformation produced by earth-stresses operating on the mass after consolidation.


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