Compositional Variations in Smectites: Part I. Alteration of Intermediate Volcanic Rocks. A Case Study from Milos Island, Greece

Clay Minerals ◽  
1993 ◽  
Vol 28 (2) ◽  
pp. 255-273 ◽  
Author(s):  
G. Christidis ◽  
A. C. Dunham
Keyword(s):  
Solid Solution ◽  
Volcanic Rocks ◽  
Negative Relationship ◽  
Volcanic Glass ◽  
The Other ◽  
Chemical Components ◽  
Solid Solution Series ◽  
Chemical Gradients ◽  
Compositional Variations

AbstractThe chemistry of smectites from some bentonite deposits derived from intermediate rocks has been examined by electron microprobe methods. A large variation in chemical composition within very short distances, principally controlled by a well-defined negative relationship between Si and A1, and between A1VI and Fe 3+ and A1VI and Mg has been observed. On the other hand, Mg does not vary systematically with either Si or Fe3+. In several bentonites beidellite coexists with montmorillonite and there is a compositional transition between the two smectite minerals, implying the existence of a possible solid-solution series. This transition occurs only when Cheto-type montmorillonites are present, being absent for Wyoming-type montmorillonites. No compositional transition between Wyoming-and Cheto-type montmorillonite was observed. It is believed that the compositional variations reflect initial chemical gradients originated during the devitrification of the volcanic glass, due to the migration of chemical components.

Epidotes of the Borrowdale Volcanic rocks of central Borrowdale

1964 ◽  
Vol 33 (265) ◽  
pp. 868-886 ◽  
Author(s):  
R. G. J. Strens
Keyword(s):  
Solid Solution ◽  
Volcanic Rocks ◽  
The Other ◽  
Solid Solution Series ◽  
Solution Series ◽  
Reaction Zones ◽  
Volcanic Series

SummaryEpidote and clinozoisite are widely distributed in the andesitic lavas and tuffs of the Borrowdale Volcanic Series. Four main types of occurrence may be distinguished, namely quartz-epidote vein fillings; ‘Shap type’ veins, bordered by pink reaction zones rich in SiO2, Na2O, and K2O; autometasomatized lavas and tuffs; and tuffs subjected to alkali metasomatism. Epidote alone formed in the quartz-epidote veins; clinozoisite is found with epidote in the other types of occurrence.Epidote and clinozoisite formed in vesicles at pressures of 10–280 kg/cm2, at temperatures of 300–550° C; epidote associated with pre-Bala mineral veins formed in the range 130–550° C at 1000 kg/cm2; epidote around the Caledonian granites probably formed up to 600° C at about 2000 kg/cm2. Clinozoisite crystallized together with epidote in the vesicles, demonstrating a gap in the clinozoisite-epidote solid solution series. Early formed epidote in vesicles is more strongly coloured than late epidote, although the compositions of the earliest and latest fractions are identical.

scholarly journals Rinkite–nacareniobsite-(Ce) solid solution series and hainite from the Ilímaussaq alkaline complex: occurrence and compositional variation

2014 ◽  
Vol 62 ◽  
pp. 1-15
Author(s):  
Jørn G. Rønsbo ◽  
Henning Sørensen ◽  
Encarnacion Roda-Robles ◽  
François Fontan ◽  
Pierre Monchoux
Keyword(s):  
Solid Solution ◽  
Electron Microprobe ◽  
Compositional Variation ◽  
Solid Solution Series ◽  
Alkaline Complex ◽  
Full Extension ◽  
X Ray ◽  
Solution Series ◽  
Compositional Variations ◽  
A Minor

In the Ilímaussaq alkaline complex, minerals from the rinkite–nacareniobsite-(Ce) solid solution series have been found in pulaskite pegmatite, sodalite foyaite, naujaite and naujaite pegmatite from the roof sequence, and in marginal pegmatite, kakortokite and lujavrite from the floor sequence. The electron microprobe analyses embrace almost the full extension of the solid solution series and confirm its continuity. The solid solution series shows similar compositional variations in the roof and floor sequences: Rinkite members of the series are found in the less evolved rocks in the two sequences, whereas nacareniobsite-Ce members occur in the most evolved rocks and pegmatites in the two sequences. The REE (+Y) content varies from 0.83 atoms per formula unit (apfu) in rinkite from pulaskite pegmatite to 1.31 apfu in nacareniobsite-(Ce) from naujaite pegmatite. The main substitution mechanisms in the solid solution series investigated in this work are 2Ca2+ = Na+ + REE3+ and Ti4+ + Ca2+ = Nb5+ + Na+. The increased contents of Nb5+ and REE3+ are only to a minor degree compensated through the F1– = O2– substitution. The chondrite normalised REE patterns of the minerals develop in a similar way in the two sequences, showing relative La-enrichment and Y-depletion from the less to the most evolved rocks. Hainite has not previously been found in the Ilímaussaq complex. It was here identified in a pulaskite pegmatite sample by a combination of X-ray diffraction giving the unit cell dimensions a = 9.5923(7) Å, b = 7.3505(5) Å, c = 5.7023(4) Å, α = 89.958(2)°, β = 100.260(1)°, γ = 101.100(2)°, and X-ray powder pattern and electron microprobe data giving the empirical formula (Ca1.62 Zr0.16Y 0.22) (Na0.87Ca1.11) (Ca 1.65 REE0.35)Na(Ti0.81Nb0.09Fe0.08 Zr0.02)(Si2O7)2O0.99F2.96. Based on published and the present data it is documented that minerals from the hainite-götzenite solid solution series show a compositional variation between the ideal end members (Y,REE,Zr)Na2Ca4Ti(Si2O7)2OF3 and NaCa6Ti(Si2O7)2OF3.

scholarly journals Spilitization of Early-Permian Volcanics from Głuszyca Górna (the Intra-Sudetic Basin, Poland)—Constraints from Chlorite Thermometry Coupled with Apatite Fission-Track Dating (AFT)

2021 ◽  
Vol 6 (1) ◽  
pp. 3
Author(s):  
Tomasz Powolny ◽  
Aneta Anczkiewicz ◽  
Dumańska-Słowik Magdalena
Keyword(s):  
Fission Track ◽  
Volcanic Rocks ◽  
Volcanic Glass ◽  
Early Permian ◽  
Fission Track Dating ◽  
Apatite Fission Track ◽  
Slow Cooling ◽  
Late Mesozoic ◽  
Compositional Variations ◽  
Apatite Fission Track Dating

The Intra-Sudetic Basin, a Late-Paleozoic intramontane trough located on the NE flank of the Bohemian Massif, is comprised of numerous outcrops of continental (extension-related) Early-Permian volcanogenic rocks that are commonly altered to spilites. In this contribution, we provide insights into the formation of spilitized (albite- and chlorite-rich) trachyandesites from the Głuszyca quarry (Lower Silesia, Poland), based on mineralogical and micro-textural investigations supported by apatite fission-track dating (AFT). Our results indicate that the trachyandesites, emplaced as a shallow-level laccolith-type body, have been strongly affected by chloritization of both aegirine and augite, combined with an occasional celadonitization of volcanic glass. Furthermore, chlortitization of sodic pyroxenes must have released notable amounts of Na+, which could be involved during later pervasive albitzation of primary andesine-labradorite. According to various chemical and semi-empirical thermometers, the replacive chlorites formed in the range of 124–170 °C. Trachyandesites from Głuszyca contain abundant fluorapatites, marked by the occurrence of swallow-type terminations, which are indicative of rapid-cooling formation conditions. Central AFT ages of the samples vary between 161–182 Ma and correspond to the Middle-Jurassic period. Meanwhile, these ages are significantly younger than the emplacement of igneous rocks during the Middle-Rotliegendes period (~299–271 Ma). The discrepancy between the stratigraphic age of the rocks and the AFT results cannot be, however, explained by, for example, slow cooling rates of magmatic body, compositional variations of apatite, or burial under Late-Mesozoic sediments. Hence, it may be assumed that the obtained AFT ages (161–182 Ma) reflect the timing of spilitization and associated partial reheating of volcanic rocks from the Intra-Sudetic Basin above the apatite partial annealing zone (70–110 °C).

scholarly journals Raman Microspectroscopic Imaging of Binder Remnants in Historical Mortars Reveals Processing Conditions

Heritage ◽  
2019 ◽  
Vol 2 (2) ◽  
pp. 1662-1683 ◽  
Author(s):  
Thomas Schmid ◽  
Petra Dariz
Keyword(s):  
Solid Solution ◽  
Raw Materials ◽  
Solid Solution Series ◽  
Crystal Lattices ◽  
Distribution Maps ◽  
Solution Series ◽  
Crystal Orientations ◽  
Cement Mortars ◽  
Amorphous Compounds ◽  
Compositional Variations

Binder remnants in historical mortars represent a record of the connection between the raw materials that enter the kiln, the process parameters, and the end product of the calcination. Raman microspectroscopy combines high structural sensitivity with micrometre to sub-micrometre spatial resolution and compatibility with conventional thin-sectional samples in an almost unique fashion, making it an interesting complementary extension of the existing methodological arsenal for mortar analysis. Raman spectra are vibrational fingerprints of crystalline and amorphous compounds, and contain marker bands that are specific for minerals and their polymorphic forms. Relative intensities of bands that are related to the same crystalline species change according to crystal orientations, and band shifts can be caused by the incorporation of foreign ions into crystal lattices, as well as stoichiometric changes within solid solution series. Finally, variations in crystallinity affect band widths. These effects are demonstrated based on the analysis of three historical mortar samples: micrometric distribution maps of phases and polymorphs, crystal orientations, and compositional variations of solid solution series of unreacted clinker grains in the Portland cement mortars of two 19th century castings, and the crystallinities of thermal anhydrite clusters in a high-fired medieval gypsum mortar as a measure for the applied burning temperature were successfully acquired.

Amorphisation of Perovskite: the Effect of Composition and Pre-Existing Cation Vacancies

1998 ◽  
Vol 540 ◽  
Author(s):  
Katherine L. Smith ◽  
Gregory R. Lumpkin ◽  
Mark G. Blackford ◽  
Eric R. Vance
Keyword(s):  
Solid Solution ◽  
National Laboratory ◽  
Argonne National Laboratory ◽  
The Other ◽  
Simple Relationship ◽  
Solid Solution Series ◽  
Cation Vacancies ◽  
Solution Series ◽  
Critical Dose ◽  
User Facility

AbstractEight perovskites of different compositions and pre-existing vacancy contents were irradiated with 1.5 MeV Kr+ ions using the HVEM-Tandem User Facility at Argonne National Laboratory. The critical dose of 1.5 MeV Kr+ ions for amorphisation (Dc) of NaNbO3, SrTiO3 and two natural perovskites varies with composition and may decrease with Na content. The Dc values of 5 members of the solid solution series from SrTiO3 to La0.67TiO3 do not exhibit a simple relationship with vacancy content: In particular, Dc(Sr0.7La0.2TiO3) is extraordinarily high (>170 × 1014 ions cm−2) compared to those of the other (Sr, La)-perovskites in the series, which have Dc, values between 2.4 and 11×1014 ions cm−2.

The crystal structures, solid solutions and infrared spectra of copiapite-group minerals

2007 ◽  
Vol 71 (5) ◽  
pp. 553-569 ◽  
Author(s):  
J. Majzlan ◽  
R. Michallik
Keyword(s):  
Solid Solution ◽  
General Formula ◽  
Solid Solutions ◽  
Infrared Spectra ◽  
Structural Type ◽  
The Other ◽  
Solid Solution Series ◽  
Complex Behaviour ◽  
Acidic Environments ◽  
Large Groups

AbstractCopiapite is a mineral of iron- and sulphate-rich acidic environments and has a general formula AFe3+4 (SO4)6(OH)2(H2O)20, where A = Fe2+, 2/3Fe3+, 2/3Al3+, Mg, Zn. The structure is built by infinite tetrahedral-octahedral chains and isolated octahedrally coordinated A sites. Our synthetic and natural copiapite samples can be divided into two large groups based on the orientation of the structural fragments. One group comprises copiapite phases where A = Al3+, Fe2+ or Fe3+ and we designate it as the structural type AL. The other group consists of copiapite with A = Mg2+, Zn2+ or Ni2+ and this is the structural type MG. The solid-solution series between Fe3+ and Al3+ copiapite is continuous. The series between Mg2+-Al3+, Mg2+-Fe3+ and Mg2+-Al3+-Fe3+ copiapite are not continuous; the samples with intermediate compositions contain two copiapite phases, one of the type AL and one of the type MG. The series between Mg2+ and Zn2+ copiapite is continuous only at 25°C. At 75°C, the Zn-rich portion of this systemcrystallizes a copiapite-like phase whose structure may be a superstructure of copiapite. The series between Al-Fe2+ and Mg-Fe2+ copiapite are not continuous and show complex behaviour of the intermediate compositions.

Thermoelectric Properties of K2Bi8Se13−xSx Solid Solutions

2005 ◽  
Vol 886 ◽  
Author(s):  
Theodora Kyratsi ◽  
Sangeeta Lal ◽  
Tim Hogan ◽  
Mercouri G. Kanatzidis
Keyword(s):  
Thermal Conductivity ◽  
Solid Solution ◽  
Seebeck Coefficient ◽  
Thermoelectric Properties ◽  
Figure Of Merit ◽  
Lattice Thermal Conductivity ◽  
The Other ◽  
Solid Solution Series ◽  
Type Character ◽  
Derivatives Of

AbstractDerivatives of β-K2Bi8Se13 are an interesting series of materials for thermoelectric investigations due to their very low thermal conductivity and highly anisotropic electrical properties. Up to now substitutions on the Bi and alkali metal sites have been studied in order to tune the thermoelectric properties. In this work, the thermoelectric properties of the sulfur-substituted K2Bi8Se13−xSx (0<x<13) are presented with respect to Seebeck coefficient, the electrical and thermal conductivity as a function of temperature. Seebeck coefficient measurements showed the n-type character of all members while electrical conductivity shows higher values compare to the other solid solution series of the same type. The lattice thermal conductivity is affected due to the Se/S disorder. The temperature dependence of the figure-of-merit ZT shows that these materials have potential for high temperatures applications with promising thermoelectric performance.

Amorphisation of Perovskite: the Effectofcomposition and Pre-Existing Cation Vacancies

1999 ◽  
Vol 556 ◽  
Author(s):  
Katherine L. Smith ◽  
Gregory R. Lumpkin ◽  
Mark G. Blackford ◽  
Eric R. Vance
Keyword(s):  
Solid Solution ◽  
National Laboratory ◽  
Argonne National Laboratory ◽  
The Other ◽  
Simple Relationship ◽  
Solid Solution Series ◽  
Cation Vacancies ◽  
Solution Series ◽  
Critical Dose ◽  
User Facility

AbstractEight perovskites of different compositions and pre-existing vacancy contents were irradiated with 1.5 MeV Kr+ ions using the HVEM-Tandem User Facility at Argonne National Laboratory. The critical dose of 1.5 MeV Kr+ ions for amorphisation (Dc) of NaNbO3, SrTiO3 and two natural perovskites varies with composition and may decrease with Na content. The D,c values of 5 members of the solid solution series from SrTiO3 to La0.67TiO3 do not exhibit a simple relationship with vacancy content: In particular, Dc(Sr0 7La0.2TiO3) is extraordinarily high (>170 × 1014 ions cm−2) compared to those of the other (Sr, La)-perovskites in the series, which have Dc values between 2.4 and 11 × 1014 ions cm−2.

Development and regional planning within the decentralized administrative frame: case study (the Jordanian Experiment)

2018 ◽  
Vol 1 (2) ◽  
pp. 60-72
Author(s):  
Mansour Safran
Keyword(s):  
Regional Planning ◽  
The Other ◽  
Negative Effects ◽  
Administrative Procedures ◽  
The Way

This aims to review and analyze the Jordanian experiment in the developmental regional planning field within the decentralized managerial methods, which is considered one of the primary basic provisions for applying and success of this kind of planning. The study shoed that Jordan has passed important steps in the way for implanting the decentralized administration, but these steps are still not enough to established the effective and active regional planning. The study reveled that there are many problems facing the decentralized regional planning in Jordan, despite of the clear goals that this planning is trying to achieve. These problems have resulted from the existing relationship between the decentralized administration process’ dimensions from one side, and between its levels which ranged from weak to medium decentralization from the other side, In spite of the official trends aiming at applying more of the decentralized administrative policies, still high portion of these procedures are theoretical, did not yet find a way to reality. Because any progress or success at the level of applying the decentralized administrative policies doubtless means greater effectiveness and influence on the development regional planning in life of the residents in the kingdom’s different regions. So, it is important to go a head in applying more steps and decentralized administrative procedures, gradually and continuously to guarantee the control over any negative effects that might result from Appling this kind of systems.   © 2018 JASET, International Scholars and Researchers Association

The Relationship between Working Environment and Internship Satisfaction Level: A Case Study Of A 4-Star Hotel Restaurant In Germany

2019 ◽  
Vol 2 (4) ◽  
pp. 276-291
Author(s):  
Chatarina Natalia Putri
Keyword(s):  
Career Development ◽  
Working Hours ◽  
Learning Opportunities ◽  
Working Environment ◽  
The Other ◽  
Satisfaction Level ◽  
Supervisory Support ◽  
Support Organization ◽  
The Relationship

There are many factors that can lead to internship satisfaction. Working environment is one of the factors that will result to such outcome. However, many organizations discarded the fact of its importance. The purpose of this study is to determine whether there is a significant relationship between working environment and internship satisfaction level as well as to determine whether the dimensions of working environment significantly affect internship satisfaction. The said dimensions are, learning opportunities, supervisory support, career development opportunities, co-workers support, organization satisfaction, working hours and esteem needs. A total of 111 questionnaires were distributed to the respondents and were processed by SPSS program to obtain the result of this study. The results reveal that learning opportunities, career development opportunities, organization satisfaction and esteem needs are factors that contribute to internship satisfaction level. In the other hand, supervisory support, co-workers support and working hours are factors that lead to internship dissatisfaction. The result also shows that organization satisfaction is the strongest factor that affects internship satisfaction while co-workers support is the weakest.

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