The chemical character of the Late Caledonian Donegal Granites, Ireland, with comments on their genesis

2006 ◽  
Vol 97 (4) ◽  
pp. 437-454 ◽  
Author(s):  
Azman A. Ghani ◽  
Michael P. Atherton
Keyword(s):  
Major Element ◽  
Large Range ◽  
Tectonic Event ◽  
Major Element Chemistry ◽  
Iapetus Ocean ◽  
High K ◽  
Granitic Magmatism ◽  
Pacific Margin ◽  
Chemical Character ◽  
Very High

ABSTRACTThe Late Caledonian granites of Donegal are all intruded into metasediments of the Dalradian Supergroup of Neoproterozoic age, which were metamorphosed and deformed during the Grampian Phase of the Caledonian orogeny at c. 470–460 m.y. They were intruded in a singular pulse well after the main tectonic event, apparently peaking at 407–402 m.y.; importantly after the strong collision of Laurentia with Baltica on closure of the Iapetus Ocean. The plutons are mainly made up of granodiorite and granite, and are all 'I' type, but different to Cordilleran ‘I’ types of the eastern Pacific margin. Major element chemistry indicates they are high-K calc-alkaline rocks with a large range in SiO2 content. However three of the plutons (Fanad, Thorr, Ardara), have very high Ba and Sr contents, even higher than Mainland Scotland counterparts; they are high Ba–Sr plutons. Three plutons (Barnesmore, Rosses, Trawenagh Bay) are evolved and are low-Ba–Sr types, while one (Main Donegal) has atypical, intermediate characteristics. The origin of the magmas is still much debated; here we suggest slab breakoffon Iapetus Ocean closure accounts for the special compositions of these magmas and the other major features of Late Caledonian granitic magmatism, including the singular intrusion peak and the associated appinite–lamprophyre suite.

A new approach to modelling differentiation (with particular focus on granitic magmatism): Equilibrated Major Element Assimilation with Fractional Crystallisation (EME-AFC)

2020 ◽  
Author(s):  
Alex Burton-Johnson ◽  
Colin Macpherson ◽  
Christopher Ottley ◽  
Geoff Nowell ◽  
Adrian Boyce
Keyword(s):  
Major Element ◽  
Crustal Contamination ◽  
Mafic Magma ◽  
Fractional Crystallisation ◽  
Geochemical Data ◽  
Magmatic Differentiation ◽  
New Approach ◽  
Mount Kinabalu ◽  
High K ◽  
Granitic Magmatism

<p>We present the new approach to AFC modelling published as Editor’s Choice in the July 2019 issue of Journal of Petrology [1].</p><p>Our new, Equilibrated Major Element – Assimilation with Fractional Crystallisation (EME-AFC) approach simultaneously models the major element, trace element, and radiogenic and oxygen isotope compositions during such magmatic differentiation (including a new approach to oxygen modelling); addressing the lack of current AFC modelling approaches for felsic, amphibole- or biotite-bearing systems. We discuss the application of this model to granitic magmatism in SE Asia and Antarctica, with particular focus on the Mt Kinabalu granitic intrusion of Borneo. We discuss the background to the model, and explain how it can be freely accessed via GitHub [2], and applied to other scenarios of magmatic differentiation; not just granitic magmatism.</p><p>We present new geochemical data for the composite units of the Mount Kinabalu, and use this to explore the discrimination between crustal- and mantle-derived granitic magmas. The isotopic data (oxygen, Hf, Sr, Nd, and Pb) indicate that the magma cannot be the result only from fractional crystallisation of a mantle-derived magma. Alkali metal compositions show that crustal anatexis is also an unsuitable processes for genesis of the intrusion. Using the new EME-AFC modelling approach, we show that the high-K pluton was generated by fractional crystallisation of a primary, mafic magma followed by assimilation of the partially melted sedimentary overburden. We propose that Mt Kinabalu was generated through low degree melting of upwelling fertile metasomatised mantle driven by regional crustal extension in the Late Miocene.</p><p>[1] Burton-Johnson, A., Macpherson, C.G., Ottley, C.J., Nowell, G.M., Boyce, A.J., 2019. Generation of the Mt Kinabalu granite by crustal contamination of intraplate magma modelled by Equilibrated Major Element Assimilation with Fractional Crystallisation (EME-AFC). J. Petrol. 60, 1461–1487.</p><p>[2] https://github.com/Alex-Burton-Johnson/EME-AFC-Modelling</p>

Relationship Analysis of Islamic Banking between Malaysia and Pakistan

2018 ◽  
Vol 5 (4) ◽  
pp. 1-6
Author(s):  
Khurram Faisal Jamal
Keyword(s):  
Large Range ◽  
Primary Objective ◽  
Islamic Banking ◽  
Islamic Banks ◽  
Relationship Analysis ◽  
Banking Institutions ◽  
Qualitative Technique ◽  
Performance Problem ◽  
Very High ◽  
Product Preference

Islamic banking is basically a system of financial intermediation, its primary objective is to avoid receipt and payment of interest. Islam does not only prohibit dealing with interest but also with liquor, pork, gambling, pornography and any other thing which are considered haram according to Shariah. The objectives of the research is to study and describe the Islamic financing techniques used by Islamic banking institutions in Malaysia and Pakistan. For this research seven variables Promotion, Product, Preference, Knowledge, Performance, Problem and Infrastructure was taken. Qualitative technique was used to answer the research objective. The findings of research indicate that lack of awareness of Islamic banking is very high in Pakistan as compared to Malaysia. A few promotions were used by Islamic banks in Pakistan while in Malaysia customers are knowledgeable about Islamic banking because banks promote them aggressively. There is a need of government and education sector support to promote Islamic banking in both countries. The study also found that Islamic banks in Malaysia have large range of products as compared to Pakistan. The practitioners from both countries are agreed at this point that BBA, Ijarah and Murabaha are more profitable and less risky than Musharaka and Mudaraba. The Islamic banking products are almost used for same purposes in both countries while some differences are also exists.  Keywords: Islamic Finance, Comparative Study, Malaysia, Pakistan

Stabilization of a very high-k tetragonal ZrO2 phase by direct doping with germanium

2009 ◽  
Vol 86 (7-9) ◽  
pp. 1626-1628 ◽  
Author(s):  
D. Tsoutsou ◽  
G. Apostolopoulos ◽  
S. Galata ◽  
P. Tsipas ◽  
A. Sotiropoulos ◽  
...  
Keyword(s):  
Tetragonal Zro2 ◽  
Zro2 Phase ◽  
High K ◽  
Very High

Major element chemistry of the geothermal sea-water at Reykjanes and Svartsengi, Iceland

1978 ◽  
Vol 42 (322) ◽  
pp. 209-220 ◽  
Author(s):  
Stefán Arnórsson
Keyword(s):  
Ground Water ◽  
Major Element ◽  
Sea Water ◽  
Geothermal Water ◽  
Ionic Exchange ◽  
Geothermal Waters ◽  
Major Element Chemistry ◽  
Element Chemistry ◽  
Geothermal Fields ◽  
Reykjanes Peninsula

SummaryHigh-temperature geothermal fields in Iceland represent localized anomalies of hot, altered rock in the uppermost part of the crust, which coincide with points of maximum tectonic/magmatic activity. These points correspond to the intersection of oblique fault swarms to the plate boundaries. Geothermal activity under mid-ocean ridges follows probably similar tectonic/magmatic anomalies.Due to high permeability sea-water invades the bed-rock of the Reykjanes Peninsula, Iceland, and is overlain by a variably thick lens of dilute ground water of meteoric origin. The variable degree of salinity of geothermal waters in the Reykjanes Peninsula has resulted from different degree of mixing of fresh ground water with the underlying sea-water-ground-water in the downflow zones around the geothermal fields. At Reykjanes the geothermal water represents heated sea-water without any freshwater mixing. The difference in the composition of sea-water or sea-water/fresh water mixtures and the geothermal waters is due to basalt/water interaction at elevated temperatures. The major-element chemistry of the geothermal water represents an equilibrium composition at the relevant aquifer temperatures. The activities of silica, calcium, sulphate, and carbonate are thus limited by the solubilities of quartz, anhydrite, and calcite. Fluoride activity is thought to be controlled by an ionic exchange reaction where it substitutes for hydroxyl groups in phyllosilicates. The ratios of individual cations and hydrogen ion are governed by ionic exchange equilibria with hydrothermal minerals, probably smectite and chlorite. The equilibrium pH for the Reykjanes and Svartsengi geothermal waters is 5·5 and 5·1 respectively. Sea-water will become somewhat acid upon heating to more than about 300 °C and equilibration with basalt, the acidity increasing with temperature.

scholarly journals Growth of Thermophilic and Hyperthermophilic Fe(III)-Reducing Microorganisms on a Ferruginous Smectite as the Sole Electron Acceptor

2007 ◽  
Vol 74 (1) ◽  
pp. 251-258 ◽  
Author(s):  
Kazem Kashefi ◽  
Evgenya S. Shelobolina ◽  
W. Crawford Elliott ◽  
Derek R. Lovley
Keyword(s):  
Electron Acceptor ◽  
Major Element ◽  
Solid Phase ◽  
Active Role ◽  
Sedimentary Environments ◽  
Major Element Chemistry ◽  
Wide Range ◽  
Structural Iron ◽  
Ferruginous Smectite ◽  
Freshwater Environments

ABSTRACT Recent studies have suggested that the structural Fe(III) within phyllosilicate minerals, including smectite and illite, is an important electron acceptor for Fe(III)-reducing microorganisms in sedimentary environments at moderate temperatures. The reduction of structural Fe(III) by thermophiles, however, has not previously been described. A wide range of thermophilic and hyperthermophilic Archaea and Bacteria from marine and freshwater environments that are known to reduce poorly crystalline Fe(III) oxides were tested for their ability to reduce structural (octahedrally coordinated) Fe(III) in smectite (SWa-1) as the sole electron acceptor. Two out of the 10 organisms tested, Geoglobus ahangari and Geothermobacterium ferrireducens, were not able to conserve energy to support growth by reduction of Fe(III) in SWa-1 despite the fact that both organisms were originally isolated with solid-phase Fe(III) as the electron acceptor. The other organisms tested were able to grow on SWa-1 and reduced 6.3 to 15.1% of the Fe(III). This is 20 to 50% less than the reported amounts of Fe(III) reduced in the same smectite (SWa-1) by mesophilic Fe(III) reducers. Two organisms, Geothermobacter ehrlichii and archaeal strain 140, produced copious amounts of an exopolysaccharide material, which may have played an active role in the dissolution of the structural iron in SWa-1 smectite. The reduction of structural Fe(III) in SWa-1 by archaeal strain 140 was studied in detail. Microbial Fe(III) reduction was accompanied by an increase in interlayer and octahedral charges and some incorporation of potassium and magnesium into the smectite structure. However, these changes in the major element chemistry of SWa-1 smectite did not result in the formation of an illite-like structure, as reported for a mesophilic Fe(III) reducer. These results suggest that thermophilic Fe(III)-reducing organisms differ in their ability to reduce and solubilize structural Fe(III) in SWa-1 smectite and that SWa-1 is not easily transformed to illite by these organisms.

Determination of major element chemistry in terrestrial waters from Antarctica by ion chromatography

1996 ◽  
Vol 739 (1-2) ◽  
pp. 257-263 ◽  
Author(s):  
K.A Welch ◽  
W.B Lyons ◽  
E Graham ◽  
K Neumann ◽  
J.M Thomas ◽  
...  
Keyword(s):  
Ion Chromatography ◽  
Major Element ◽  
Major Element Chemistry ◽  
Element Chemistry

Characterization of clays from the Foumban region (west Cameroon) and evaluation for refractory brick manufacture

Clay Minerals ◽  
2018 ◽  
Vol 53 (3) ◽  
pp. 447-457
Author(s):  
A. Pountouenchi ◽  
D. Njoya ◽  
A. Njoya ◽  
D. Rabibisao ◽  
J.R. Mache ◽  
...  
Keyword(s):  
Material Properties ◽  
Major Element ◽  
Raw Materials ◽  
Mineralogical Composition ◽  
Refractory Brick ◽  
Major Element Chemistry ◽  
End Products ◽  
Materials Used ◽  
Steel Mould

ABSTRACTThree clayey materials named MY3, KK and KG originating from the Foumban region (west Cameroon) were analysed to determine their granulometry, plasticity, major-element chemistry and mineralogy. Dilatometric and ceramic behaviour were also investigated. Clays were shaped by uniaxial pressing in a steel mould. Shaped samples were heated at 1300, 1400 and 1500°C. The end products were characterized in terms of their density, porosity and compressive strength. Raw materials differ in terms of their mineralogical composition, grain-size distribution, Al2O3 content and the nature and abundance of impurities inducing specific thermal behaviour during dilatometric analysis and sintering tests. The final material properties may be related to the main features of the raw materials used.

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