scholarly journals Identifying Correlation of Coal Seams in the Tien Hai Area, Northern Vietnam by Using Multivariate Statistic Methods

2021 ◽  
Vol 1 (2) ◽  
Author(s):  
The Hung KHUONG ◽  
Phuong NGUYEN ◽  
Thi Cuc NGUYEN ◽  
Nhu Sang PHAM ◽  
Danh Tuyen NGUYEN

In northern Vietnam, the Tien Hai area is considered a high potential area of coal deposits. Twohundred fifty-six geochemical coal samples of 13 cores in the Tien Hai area investigate coal seams andcoal deposits to identify the correlation of coal seams. According to the statistical method and clusteranalysis of geochemical samples, the results indicate that the Mg, V, As, Ca, Zn, Cr, Co, K, Na, Sr, Fe,Ge, Re, U, Mo, Th, and Ga elements are good indicator elements of the major and trace elements in coal.Most of them comply with the normal or lognormal distribution rules. Besides, the Yb, Sc, Ho, Er, Tm,Lu, Y, Tb, Pr, Dy, and Sm elements are also good indicator elements for rare earth elements in the region.Therefore, the selected elements are used to identify the correlation of the coal seams in the Tien Hai area.Based on the similarity degree between studied objects, the results of grouping boreholes in coal seamsshow that the correlation of coal seam TV2-11 is suitable and acceptable, the coal seams TV3-6a, TV3-6b, and TV3-6c can be grouped into the coal seam TV3-6. These results present that the models can helpstudy geochemical coal samples and identify the correlation of the coal seams in the Tien Hai area.Additionally, the statistical analysis shows a remarkable degree to determine the correlation of the coalseams. Geochemical coal data can help to evaluate the indicator elements of the major, trace elements,and rare earth elements in coal seams and coal rashing of adjoining and pillar rocks in the Tien Hai area,northern Vietnam.

2019 ◽  
Vol 486 (5) ◽  
pp. 583-587
Author(s):  
A. M. Agashev

The paper presents the results of major and trace elements composition study of garnet megacrysts from Mir kimberlite pipe. On the major elements composition those garnets classified as low Cr and high Ti pyropes. Concentrations of TiO2 show a negative correlation with MgO и Cr2O3 contents in megacrysts composition. Fractional crystallization modeling indicates that the most appropriate melt to reproduce the garnet trace elements signatures is the melt of picritic composition. Composition of garnets crystallized from kimberlite melt do not correspond to observed natural garnets composition. Kimberlites contain less of Ti, Zr, Y and heavy REE (rare earth elements) but more of very incompatible elements such as light REE, Th, U, Nb, Ba then the model melt composition that necessary for garnet crystallization.


2001 ◽  
Vol 34 (3) ◽  
pp. 1255
Author(s):  
S. PANILAS ◽  
G. HATZIYANNIS

Multivariate statistical analysis was used on existing geochemical data of the Drama lignite deposit, eastern Macedonia, Greece. Factor analysis with varimax rotation technique was applied to study the distribution of major, trace and rare earth elements in the lignite and 850°C lignitic ash, to find a small set of factors that could explain most of the geochemical variability. The study showed that major elements AI, Na, Κ, contained in the lignite samples, presented high correlation with most of the trace and rare earth elements. In 850°C lignitic ashes major and trace elements present different redistribution. Only Al remained correlated with the trace elements Co, Cr, Rb, Ta, Th, Ti, Sc and rare earths related with inorganic matter in the lignite beds. Trace elements Fe, Mo, U, V, W, and Lu were associated with organic matter of lignite and had also been affected by the depositional environment.


2014 ◽  
Vol 22 (9) ◽  
pp. 6789-6799 ◽  
Author(s):  
Željka Fiket ◽  
Martina Rožmarić ◽  
Matea Krmpotić ◽  
Ljudmila Benedik

2020 ◽  
Vol 105 (6) ◽  
pp. 922-931 ◽  
Author(s):  
Melanie J. Sieber ◽  
Franziska Wilke ◽  
Monika Koch-Müller

Abstract The presence of Ca-Mg-carbonates affects the melting and phase relations of peridotites and eclogites in the mantle, and (partial) melting of carbonates liberates carbon from the mantle to shallower depths. The onset and composition of incipient melting of carbonated peridotites and carbonated eclogites are influenced by the pure CaCO3-MgCO3-system making the understanding of the phase relations of Ca-Mg-carbonates fundamental in assessing carbon fluxes in the mantle. By performing high-pressure and high-temperature experiments, this study clarifies the suprasolidus phase relations of the nominally anhydrous CaCO3-MgCO3-system at 6 GPa showing that Ca-Mg-carbonates will (partially) melt for temperatures above ~1300 °C. A comparison with data from thermodynamic modeling confirms the experimental results. Furthermore, partition coefficients for Li, Na, K, Sr, Ba, Nb, Y, and rare earth elements between calcite and dolomitic melt, Ca-magnesite and dolomitic melt, and magnesite and dolomitic melt are established. Experiments were performed at 6 GPa and between 1350 to 1600 °C utilizing a rotating multi-anvil press. Rotation of the multi-anvil press is indispensable to establish equilibrium between solids and carbonate liquid. Major and trace elements were quantified with EPMA and LA-ICP-MS, respectively. The melting temperature and phase relations of Ca-Mg-carbonates depend on the Mg/Ca-ratio. For instance, Ca-rich carbonates with a molar Mg/(Mg+Ca)-ratio (XMg) of 0.2 will transform into a dolomitic melt (XMg = 0.33–0.31) and calcite crystals (XMg = 0.19–0.14) at 1350–1440 °C. Partial melting of Mg-rich carbonates (XMg = 0.85) will produce a dolomitic melt (XMg = 0.5–0.8) and Ca-bearing magnesite (XMg = 0.89–0.96) at 1400–1600 °C. Trace element distribution into calcite and magnesite seems to follow lattice constraints for divalent cations. For instance, the compatibility of calcite (XMg = 0.14–0.19) for Sr and Ba decreases as the cation radii increases. Ca-Mg-carbonates are incompatible for rare earth elements (REEs), whereby the distribution between carbonates and dolomitic melt depends on the Mg/Ca ratio and temperature. For instance, at 1600 °C, partition coefficients between magnesite (XMg = 0.96) and dolomitic melt (XMg = 0.8) vary by two orders of magnitudes from 0.001 to 0.1 for light-REEs to heavy-REEs. In contrast, partition coefficients of REEs (and Sr, Ba, Nb, and Y) between magnesite (XMg = 0.89) and dolomitic melt (XMg = 0.5) are more uniform scattering marginal between ~0.1–0.2 at 1400 °C.


2017 ◽  
Vol 62 (3) ◽  
pp. 495-507
Author(s):  
Jacek Nowak ◽  
Magdalena Kokowska-Pawłowska

AbstractCoal waste is formed during coal mining and processing operations. That waste comprises mainly sedimentary rocks that occur in roofs and floors of underground workings and in partings in coal seams. It contains numerous trace elements, including rare earth elements (REEs). Hypergenic processes that take place in coal waste piles may lead to endogenous fires. Thermal transformations of waste have an effect on changes in its phase and chemical composition, including the concentration of trace elements.The paper presents changes in the content of selected rare earth elements (Sc, Y, La, Ce, Nd, Sm, Eu, Tb, Yb, Lu) in wastes of varying degree of thermal transformation. The results of REE content determination in lump samples were subjected to statistical analysis and coefficients of correlation between the studied rare earth elements and the main chemical constituents were determined.The primary carriers of REEs in coal waste are clay minerals. Phase transformations that take place at high temperatures (including dehydroxylation of clay minerals and formation of minerals characteristic of contact metamorphism) cause changes in the concentration of rare earth elements.


1991 ◽  
Vol 28 (7) ◽  
pp. 1050-1057 ◽  
Author(s):  
Luc Harnois ◽  
Raymond Mineau

The Île Cadieux alnöite, a small Cretaceous intrusion, is a member of the Monteregian Hills Petrographic Province. Mineral chemistry was determined for olivine, spinel, clinopyroxene, melilite, and a potassium–iron–nickel sulphide akin to djerfisherite. Whole rocks were analysed for major elements and 24 trace elements (including rare-earth elements). The Île Cadieux alnöitic rocks have greater MgO/Al2O3 ratios than most alnöites but are otherwise similar to typical alnöites with respect to major and trace elements. Comparison of spinel and whole-rock chemical compositions from the Île Cadieux and Île Bizard (located 15 km to the northeast) alnöitic intrusions suggests that these magmas were generated under different physicochemical conditions of melting, or alternatively that they are fractions of a single magma which crystallized under different conditions.


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