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Wyszukujesz frazę "Alavi, Ghafour" wg kryterium: Autor


Wyświetlanie 1-3 z 3
Tytuł:
Mineralogy and geochemistry of rare earth elements in the Moyil Valley alteration zones, Meshkinshahr (northwest Iran)
Autorzy:
Naseri, Hossain
Jamadi, Mahnaz
Radmard, Kaikhosrov
Alavi, Ghafour
Powiązania:
https://bibliotekanauki.pl/articles/1841625.pdf
Data publikacji:
2020
Wydawca:
Uniwersytet im. Adama Mickiewicza w Poznaniu
Tematy:
Sabalan Mountain
Cenozoic
chondrite-normalised
HREE
trachyandesite
Sabalan
Kenozoik
chondryt
trachyandezyt
Opis:
Sabalan Mountain (northwest Iran) witnessed intense volcanic activity during the Cenozoic (Plio-Pleistocene). The result of this manifests itself in the conical geometry of the Sabalan stratovolcano and ahigh hydrothermal gradient around it, which can be detected by geological phenomena such as hot springs, smoke gases and steam outlet pores. The high hydrothermal slope and upward migration of hot water in this area have caused extensive alteration zones in the host rocks. A mineralogical study of alteration zones in thewells drilled in the Moyil Valley to the northwest of Sabalan Mountain has revealed the presence of phyllic, argillic, calcitic and propylitic alterations in volcanic rocks (trachyandesite) and alteration phyllic and propylitic ones in monzonite rocks. In chondrite-normalised rare-earth-element diagrams, trachyandesite rocks exhibit an HREEs enrichment when compared to MREEs and LREEs in propylitic and calcitic alteration zones. This result can be explained by the acidic nature of hydrothermal fluids containing complex ions such as (SO-2, Cl-). The (La/Yb)cn, (La/Sm)cn and (Tb/Yb)cn ratios for argillic, phyllic, propylitic and calcitic alteration zones have revealed that they are higher in fresh rocks compared to altered rocks, suggesting the enrichment of HREEs in comparison to LREEs and MREEs. The anomalies of Eu do not change remarkably in the argillic and propylitic alteration zones of trachyandesite rocks; apparently, alteration hadno effect on them. Such behaviour reflects the presence of gold cations in Eu+3 formed at temperatures below 250°C. Eu anomalies increased in propylitic alteration zones in monzonite rocks and calciticand phyllic alteration zones in trachyandesiterocks.
Źródło:
Geologos; 2020, 26, 3; 219-231
1426-8981
2080-6574
Pojawia się w:
Geologos
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Geochemistry of skarn and porphyry deposits in relation to epithermal mineralization in the Arasbaran metallogenic zone, NE Tabriz, Iran
Autorzy:
Alavi, Ghafour
Radmard, Kaikhosrov
Zamanian, Hassan
Hosseinzadeh, Mohammad Reza
Khalaji, Ahmad Ahmadi
Powiązania:
https://bibliotekanauki.pl/articles/2058563.pdf
Data publikacji:
2020
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
Arasbaran metallogenic zone
porphyry deposits
skarn deposits
epithermal deposits
fluid inclusions
Iran
Opis:
The Arasbaran metallogenic zone in northern Iran is part of the Alborz-Azerbaijan magmatic zone, which developed along the southern margin of Eurasia during the Early Mesozoic-Late Cenozoic. This region hosts precious and base metal mineralization, including porphyry, skarn, and epithermal copper, molybdenum, and gold deposits. Rare earth element variations across all the deposits are similar, indicating a similar source for these elements. The north-west trending belt comprising the Nabijan to the Sonajil deposits consistently shows chiefly alkaline conditions of formation. Fluid inclusion studies indicate that both high and low temperature hydrothermal fluids participated in the formation of all of the deposits. The mineralization age decreases from north to south and east to west and, although metal zonation is complex, the Cu-Au association post-dated the Cu-Mo mineralization reflecting that the ore fluid evolved in terms of both cooling and chemical changes due to fluid-fluid and fluid-rock interactions. In this region most deposits record a concentric zonation, with the centres preserving porphyry and skarn deposits and deposits becoming progressively epithermal toward the outer parts of the mineralizing system. According to this, the mineralization age decreases from the porphyry and skarn deposits to the epithermal deposits. The homogenization temperature and salinity both decrease from the centre to the outer zone. The pattern of homogenization temperature zonation, which is concordant with salinity zonation, suggests that fluids migrated up-dip and towards the margins of the zonation system.
Źródło:
Geological Quarterly; 2020, 64, 1; 141--164
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A study of challenges in entrepreneurship development and potential role of public sector in mitigating them – evidence from Kurdistan region of Iraq
Autorzy:
Alavi, Hamed
Ghafour, Shano Ibrahim
Powiązania:
https://bibliotekanauki.pl/articles/2064722.pdf
Data publikacji:
2019
Wydawca:
STE GROUP
Tematy:
entrepreneurship
economy
entrepreneurship ecosystem
market
finance
Opis:
The purpose of this paper is to identify the main challenges faced by entrepreneurs in the Kurdistan region of Iraq and possible ways that regional public sector can take for the purpose of improving entrepreneurship development. Given the importance of entrepreneurs in the economic development and job creation, it’s critical to understand what drives entrepreneurs to become less effective and to investigate how the implementation of “entrepreneurship ecosystem” practiced by public policy makers mitigates these challenges. As a result, authors strive to answers two main questions in this paper: “What are the factors that hold back entrepreneurs in the Kurdistan Region to start their own businesses? “And “What measures the local government can take to mitigate such challenges?” The methodology used in this study is quantitative approach, involving a survey questionnaire. This paper consists of four parts: After the introduction, second part will provide empirical data on challenges facing entrepreneurs in Kurdistan Region of Iraq. Discussion and analysis of the findings are done in the third part. Finally, in the last part, paper will offer conclusions by summarizing the key findings.
Źródło:
Multidisciplinary Aspects of Production Engineering; 2019, 2, 1; 589--599
2545-2827
Pojawia się w:
Multidisciplinary Aspects of Production Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-3 z 3

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