Results 41 to 50 of about 1,340 (151)

Mineral chemistry of apatite, amphibole, biotite, and magnetite from the Masjeddaghi porphyry Cu-Au deposit, NW Iran: petrogenetic and metallogenic implications

open access: yesFrontiers in Earth Science
The Masjeddaghi porphyry Cu-Au deposit is situated in the Alborz-Azarbaijan structural zone of northwest Iran. Chemical compositions of rock-forming (biotite, amphibole) and accessory minerals (magnetite, apatite) in the potassic to propylitic altered ...
Zohreh Rahnama   +3 more
doaj   +1 more source

A Reassessment of Petrochemistry of ~1.2 Ga Tonalitic Rocks of the Northern Tugela Terrane, Natal Metamorphic Belt, South Africa: Further Constraints on the Evolution of This Belt

open access: yesGeological Journal, EarlyView.
Our petrochemical studies on ~1.2 Ga granitoids of the Natal Metamorphic Belt, South Africa, do not suggest any property similar to Phanerozoic‐style subduction‐related granitoids. Plot of Kotongweni Tonalite in Y versus Sr diagram (after Moyen 2011), note that most samples have Sr/Y < 50.
Palesa Leuta   +2 more
wiley   +1 more source

Apatite in Carbonatite Preserving Primary Magmatic, Post‐Magmatic Overgrowth, and Post India‐Asia Collision‐Related Hydrothermal Alteration: Evidenced From U–Pb Isotope and Trace Element Geochemistry

open access: yesGeological Journal, EarlyView.
U–Pb isotope and trace element geochemistry of apatite from carbonatites of Peshawar Plain Alkaline Igneous Province, western Himalaya shows Permo‐Carboniferous magmatism, an additional magmatic pulse during Cretaceous, and post‐magmatic hydrothermal/metasomatism during Oligocene. ABSTRACT U–Pb isotope and trace element geochemistry of apatite combined
Mehboob ur Rashid   +9 more
wiley   +1 more source

Heterogeneous Exhumation Mechanisms in Neoproterozoic Collisional Metamorphism: P–T Constraints From Pelotas and Punta del Este Terranes, Southern Brazil and Uruguay

open access: yesGeological Journal, EarlyView.
Petrography, thermobarometry, and pseudosection modelling reveal peak metamorphic conditions of 3–7.5 kbar and 520°C–800°C in Tonian‐Cryogenian orthogneisses of the Dom Feliciano Belt. Metamorphic field gradients of 27°C/km–39°C/km and variable exhumation mechanisms support correlation of these units as remnants of a Himalayan‐type Piratini Orogeny ...
Thaiane Niederauer‐Santos   +6 more
wiley   +1 more source

The Alteration Mechanism of Copper-bearing Biotite and Leachable Property of Copper-bearing Minerals in Mulyashy Copper Mine, Zambia

open access: yesScientific Reports, 2019
The XRF, XRD, polarizing microscopy and SEM-EDS were used to study the alteration mechanism of copper-bearing biotite and the leachable property of copper-bearing minerals in Mulyashy Copper Mine, Zambia.
Gai-rong Wang   +4 more
doaj   +1 more source

“Excess Ar” by laboratory alteration of biotite

open access: yesGeology, 2022
AbstractMany biotite phenocrysts from marine tephra layers have substoichiometric potassium concentrations and alkali occupation &lt;&lt;2.0 atoms per formula unit. Diagenetic alteration is an expected effect of exposure of fresh magmatic minerals to interstitial water and brine intrusions after the deposition and burial of sediments.
Villa, IM, Bosio, G
openaire   +2 more sources

Iron Physiology and Its Impact on Atopic Diseases: An EAACI Taskforce Report

open access: yesAllergy, EarlyView.
ABSTRACT Iron is essential for oxygen transport, energy metabolism, and immune regulation. Yet iron deficiency is the most common micronutrient disorder across all age groups, affecting nearly one quarter of the global population. Iron deficiency triggers nutritional immunity, a host defense mechanism that withholds and redistributes iron, contributing
Franziska Roth‐Walter   +19 more
wiley   +1 more source

An Investigation on the Composition of Biotite from Mashhad Granitoids, NE Iran [PDF]

open access: yesJournal of Sciences, Islamic Republic of Iran, 2010
Compositions of biotite from three different rock types of Mashhad granitoids, i.e., granodiorite, monzogranite and leucogranite in NE of Iran have been documented by electron microprobe and wet chemistry for Fe3+ and Fe2+.
A.A.T. Shabani
doaj  

Lithic analysis in African archaeology: Advances and key themes

open access: yesArchaeometry, EarlyView.
Abstract Stone artifacts (lithics) preserve for extended periods; thus they are key evidence for probing the evolution of human technological behaviors. Africa boasts the oldest record of stone artifacts, spanning 3.3 Ma, rare instances of ethnographic stone tool‐making, and stone tool archives from diverse ecological settings, making it an anchor for ...
Deborah I. Olszewski   +2 more
wiley   +1 more source

Magnetic petrology of the Água Azul and Água Limpa granodiorites, southern portion of the Carajás Domain – Pará [PDF]

open access: yesGeologia USP. Série Científica, 2013
The Água Azul and Água Limpa granodiorites (AAGrd and ALGrd, respectively) outcrop in the extreme southern of the Carajás Domain as two elongated bodies following the EW regional trend and were previously included in the Xingu Complex. The ALGrd consists
Eleilson Oliveira Gabriel   +1 more
doaj   +1 more source

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