Response of silicate chemical composition variation on thermal metamorphism of ordinary chondrites and classification of petrologic types: the case of L chondrites from Grove Mountains, Antarctica

2021 ◽  
Author(s):  
Chuantong Zhang ◽  
Bingkui Miao ◽  
Zhipeng Xia ◽  
Qinglin Xie
Keyword(s):  
Chemical Composition ◽  
Ordinary Chondrites ◽  
Thermal Metamorphism ◽  
Composition Variation ◽  
Grove Mountains

Classification of 24 New Ordinary Chondrites from the Grove Mountains, Antarctica

2004 ◽  
Vol 78 (5) ◽  
pp. 1052-1059 ◽  
Author(s):  
LU Ren ◽  
MIAO Bingkui ◽  
WANG Guiqing ◽  
DAI Deqiu ◽  
LIN Yangting ◽  
...  
Keyword(s):  
Ordinary Chondrites ◽  
Grove Mountains

The Mineral Chemistry and Classification of New Ordinary Chondrites Collected in Antarctica

2012 ◽  
Vol 621 ◽  
pp. 125-129
Author(s):  
Bao Hua Wang ◽  
Shi Jie Li ◽  
Bing Kui Miao
Keyword(s):  
High Pressure ◽  
Mineral Chemistry ◽  
Shock Metamorphism ◽  
Ordinary Chondrites ◽  
Similar Composition ◽  
Severe Shock ◽  
Grove Mountains

Petrography and mineral chemistry of ninety-eight ordinary chondrites from Grove Mountains, Antarctica, have been studied, in order to assign their chemical-petrographic types. The chemical-petrographic types of these meteorites are presented below: 36 H-groups (21 H4, 9 H5, 6 H6) and 62 L-groups (25 L5, 37 L6). The compositions of olivines and low-Ca pyroxenes in the all these ordinary chondrites have similar composition, respectively, reflecting some degree thermodynamics equilibration in them. The weathering degrees of all the ordinary chondrites, consisting of predominant weathering degrees of W1, suggest lightly weathered among them. More than 30% meteorites experienced severe shock metamorphism, as indicated by the presences of shock-induced melt veins and pockets. These heavily shocked meteorites provide us with natural samples for study of high-pressure polymorphs of minerals.

PETROGRAPHY, MINERAL CHEMISTRY AND CLASSIFICATION OF SOME GROVE MOUNTAINS METEORITES

2014 ◽  
Vol 25 (4) ◽  
pp. 369-377 ◽  
Author(s):  
Shijie Li ◽  
Shijie Wang ◽  
Shen Liu ◽  
Xiongyao Li ◽  
Yang Li ◽  
...  
Keyword(s):  
Mineral Chemistry ◽  
Grove Mountains

scholarly journals Discrimination of Genealogical Groups of Arabica Coffee by the Chemical Composition of the Beans

2019 ◽  
Vol 11 (16) ◽  
pp. 141
Author(s):  
Larissa O. Fassio ◽  
Marcelo R. Malta ◽  
Gladyston R. Carvalho ◽  
Antônio A. Pereira ◽  
Ackson D. Silva ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Chemical Composition ◽  
Chemical Markers ◽  
Total Lipids ◽  
Germplasm Bank ◽  
Total Sugars ◽  
Coffee Beans ◽  
Different Levels ◽  
Important Marker

This work aimed to characterize and discriminate genealogical groups of coffee as to the chemical composition of the grains through the model created by PLS-DA method. 22 accessions of Coffea arabica, from the Active Germplasm Bank of Minas Gerais, were divided into groups according to the genealogical origin. Samples of ripe fruits were harvested selectively and processed by the wet method, to obtain pulped coffee beans, with 11% (b.u.) of water content. The raw beans were assessed as to the content of polyphenols, total sugars, total lipids, protein, caffeine, sucrose, and fatty acids. The data were submitted the chemometric analysis, PCA and PLS-DA. The results of PLS-DA identified the variables which most influence the classification of genealogical groups and possible chemical markers to accessions processed by the pulped method. The sucrose content was an important marker for the Exotic accession group. However, the content of polyphenols has been identified as a marker for the group Tymor Hybrid, and the caffeine for the bourbon group. The different fatty acids have been identified as markers for all genealogical groups, at different levels. The model PLS-DA is effective in discriminating genealogical groups from the chemical composition of the beans.

Chemical Composition as a Criterion in the Classification of Actinomycetes

1971 ◽  
pp. 47-72 ◽  
Author(s):  
H.A. Lechevalier ◽  
Mary P. Lechevalier ◽  
Nancy N. Gerber
Keyword(s):  
Chemical Composition

Effect of the chemical composition of 35HGSL steel on shrinkage, casting defects and microstructure

2020 ◽  
pp. 171-179
Author(s):  
М.Л. Скрябин
Keyword(s):  
Chemical Composition ◽  
Heat Removal ◽  
Casting Defects ◽  
Secondary Crystallization ◽  
Cooling Intensity ◽  
Steel Castings ◽  
Investment Models

Стальные отливки на сегодняшний день стали неотъемлемой частью современного литейного производства. В процессе получения отливок неизбежно появляются какие-либо дефекты. В данной работе рассмотрены причины образования дефектов при изготовлении отливок из стали 35ХГСЛ при литье по выплавляемым моделям. Также рассмотрены особенности отвода теплоты от отливки при первичной и вторичной кристаллизации. Приведена классификация зон отливок по ориентации кристаллов в отливках. Выявлена закономерность влияния интенсивности охлаждения на характер усадки. Today, steel castings have become an integral part of modern foundry production. In the process of obtaining castings, any defects inevitably appear. In this paper, we consider the production reasons for the formation of defects in the manufacture of castings made of 35XGSL steel when casting on investment models. The features of heat removal from the casting during primary and secondary crystallization are also considered. The classification of casting zones by the orientation of crystals in castings is given. The regularity of the influence of the cooling intensity on the shrinkage character is revealed.

Supergene alteration of metamorphic chlorite in an amphibolite from Massif Central, France

Clay Minerals ◽  
1982 ◽  
Vol 17 (2) ◽  
pp. 159-173 ◽  
Author(s):  
D. Proust
Keyword(s):  
Chemical Composition ◽  
Low Temperature ◽  
Grain Boundaries ◽  
Mixed Layer ◽  
Low Pressure ◽  
Chemical Changes ◽  
Massif Central ◽  
Rock Structure ◽  
Initial Rock

AbstractThe mineralogical and chemical changes of sheridanite were followed in different alteration horizons as weathering of its host amphibolite increased. Microscopic and microprobe analyses of phases produced in or around the chlorite allowed a classification of the different alteration stages relative to their position in the profile. In the unweathered rock, prehnite and a sericite—kaolinite assemblage appear to have formed at grain boundaries between chlorites and plagioclases. These represent low-pressure (PH2O < 2.5 ± 1 Kb) and low-temperature (320–360°C) metamorphic phases. In the saprock, where initial rock structure is still preserved, chlorites weather to a more or less regular mixed-layer chlorite-vermiculite. In the saprolite, large-grain (20 µm) vermiculite forms in the clayey zones (plasma) when rock structure is destroyed. The chemical composition of these newly-formed minerals is influenced by the original chlorites and mixed-layer minerals.

Research on Aging Characteristics and Chemical Composition of Hydrogenated Transformer Oil

2012 ◽  
Vol 614-615 ◽  
pp. 1131-1137 ◽  
Author(s):  
Xu Dong Ouyang ◽  
Yi Hua Qian ◽  
Wei Su ◽  
Yi Bin Huang
Keyword(s):  
Chemical Composition ◽  
Electrical Properties ◽  
Dielectric Loss ◽  
Loss Factor ◽  
Kinematic Viscosity ◽  
Chemical Properties ◽  
Dielectric Loss Factor ◽  
Transformer Oil ◽  
Composition Variation

Under the condition of Baader aging, the chemical composition variation and the effect of transformer oil aging on electrical properties such as dielectric loss factor and physic-chemical properties such as kinematic viscosity were studied during aging. Moreover, the correlation between hydrogenated transformer oil electrical and physic-chemical properties and its chemical composition variation were investigated.

Thermal Metamorphism of Primitive Meteorites—XII. The Enstatite Chondrites Revisited

2005 ◽  
Vol 2 (3) ◽  
pp. 215 ◽  
Author(s):  
Ming-Sheng Wang ◽  
Michael E. Lipschutz
Keyword(s):  
Radiochemical Neutron Activation Analysis ◽  
Parent Material ◽  
Ordinary Chondrites ◽  
Terrestrial Environment ◽  
Volatile Element ◽  
Thermal Metamorphism ◽  
Report Data ◽  
Element Contents ◽  
Type 3 ◽  
Solid Bodies

Environmental Context.The first Solar System material condensed 4.567 billion years ago, rapidly forming planetesimals—solid bodies that might combine to form planets (accretion) or survive as asteroidal meteorites. Earth’s main accretion ended within the next 30 million years, but subsequent high temperatures essentially erased evidence of this history. However, heating in these early episodes produced effects uniquely recorded by 14 volatile trace elements. The volatile element composition of chondritic meteorites, whose parent material formed closest to Earth, may thus provide important information about early planetesimal evolution. Abstract.We report data for 14 trace and ultratrace elements—Au, Co, Sb, Ga, Rb, Ag, Cs, Te, Zn, Cd, Bi, Tl, In (ordered by increasing putative nebular volatility)—in 13 enstatite (E) chondrites recovered from Antarctica and two E inclusions in the Kaidun polymict breccia that fell in 1980. These data, determined by radiochemical neutron activation analysis (RNAA), essentially double the amount of information known for E chondrites, whose parent materials formed closest to the Sun in the chondrite-forming nebular region. We discuss here the data for all 29 samples studied. The meteoritic suite studied here includes both representatives of previously rare types—like high-iron EH3 and EH5 individuals—but also unique individuals and previously unknown low-iron, EL3, chondrites. Prior hypothetical assertions by others are corrected by the new data. Volatile element contents of EL3 and EH3 chondrites are variable, but comparable, like those of type 3 ordinary chondrites (i.e. H3, L3, and LL3). Volatile element contents of EH4 chondrites are at least as high as those of the E3 types, in contrast to the lower contents of H4, L4, and LL4 types. Compositionally, E3,4 chondrites reflect only nebular condensation and/or accretion processes. Volatiles in E5 and E6 chondrites—whether of EH, EL or unique ones—are depleted relative to cosmic (i.e. CI1) or E3,4 chondrite abundances. The evidence indicates that E5,6 chondrites compositionally reflect vaporization and loss of volatiles during open-system, thermal metamorphism of their parent(s); this may have been the terrestrial environment during Earth’s formation from early planetesimals. Compositional differences between Antarctic E5,6 chondrites and contemporary falls probably do not reflect weathering during the long residence of these chondrites in Antarctica. They might reflect differences in the starting compositions and/or metamorphic conditions in the parent(s).

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