Results 31 to 40 of about 1,754 (181)

Petrography and petrology of the Ayghalesi granite, east of Takab area (northwest of Iran) [PDF]

پترولوژی, 2017
The investigated granite intrusion is located at the north of Ayghalesi village, east of Takab The Ayghalesi granite has been intruded the Eocene sandstone and conglomerate rocks and low grade metamorphic hornfels have been metamorphosed host rocks.
Saeed Kamran, Ahmad Jahangiri, Robab Hajialioghli, Mohsen Moayyed   +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

Geological 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, Saumitra Misra, Thembiso O. Basupi   +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

Geological 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, Hafiz U. Rehman, Hao‐Yang Lee, Sun‐Lin Chung, Kaushik Das, Kazumasa Aoki, Muhammad Jawad Zeb, Nasir Ahmad, Muhammad Hussain, Hiroshi Yamamoto   +9 more
wiley   +1 more source

Incidence of Alkali Release in Concrete Dams. Evaluation of Alkalis Releasable by Feldspars [PDF]

MATEC Web of Conferences, 2018
Alkali release from aggregates can constitute a source of alkalis in concrete exposed to wet environments for long periods of time. Feldspars are one of the minerals that can release alkalis to the concrete with time. The formation of reaction products in the interface with the paste due to the alkali release from sodium and potassium feldspars has ...
Menéndez E., García-Rovés R., Aldea B.   +2 more
openaire   +3 more sources

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

Geological 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, Carla Cristine Porcher, Daniel Triboli Vieira, Edinei Koester, Diego Jaldín, Karina Luengo, Luisa Caon   +6 more
wiley   +1 more source

Chemical classification of common volcanic rocks based on degree of silica saturation and CaO/K2O ratio

Anais da Academia Brasileira de Ciências, 2021
Modal classifications of common volcanic rocks are expensive, difficult, or impossible to attain. As a consequence, these rocks are classified using the chemical composition.
JOÃO O.S. SANTOS, LÉO A. HARTMANN
doaj   +1 more source

Automated particle analysis of D.B. Cooper's tie

Journal of Forensic Sciences, EarlyView.
Abstract Automated particle analysis (APA) using scanning electron microscopy (SEM) and energy‐dispersive x‐ray spectrometry (EDS) is a well‐known method in forensics, especially as it is applied to gunshot residue analysis. Here we describe the analysis of particles lifted from D.B. Cooper's tie, which was left on the hijacked plane in 1971.
Thomas G. Kaye, Kent L. Rhodes
wiley   +1 more source

Mortars From Punic and Hellenistic–Roman Solunto: Materials, Formulations, and Technology

Archaeometry, EarlyView.
ABSTRACT This study presents an archaeometric investigation of 18 hydraulic rendering and bedding mortars from Punic and Hellenistic–Roman Solunto (NW Sicily). The research aimed to characterize raw materials, reconstruct manufacturing sequences, and evaluate technological proficiency through mineralogical and petrochemical analyses.
G. Montana, G. Polizzi, C. Portale, M. Gasparo Morticelli, L. Randazzo   +4 more
wiley   +1 more source

Excess ⁴⁰Ar in Alkali Feldspar and ^206,207Pb in Apatite Caused by Fluid-Induced Recrystallisation in a Semi-Closed Environment in Proterozoic (Meta)Granites of the Mt Isa Inlier, NE Australia

Geosciences
Interpretation of 40Ar/39Ar dates of alkali feldspar and U-Pb dates of apatite depends on the dominant mechanism of isotopic transport in these minerals, which can be either diffusion or fluid-assisted dissolution-reprecipitation.
Daniil Popov, Richard Spikings, André Navin Paul, Maria Ovtcharova, Massimo Chiaradia, Martin Kutzschbach, Alexey Ulianov, Gary O’Sullivan, David Chew, Kalin Kouzmanov, Eszter Badenszki, J. Stephen Daly, Joshua H. F. L. Davies   +12 more
doaj   +1 more source

3D zoning of barium in alkali feldspar

American Mineralogist, 2023
Abstract Interpretation of chemical zoning within igneous minerals is critical to many petrologic studies. Zoning in minerals, however, is commonly observed in thin sections or grain mounts, which are random 2D slices of a 3D system. Use of these 2D sections to infer 3D geometries requires a set of assumptions, often not directly tested,
Jordan Lubbers, Adam Kent, Douglas Meisenheimer, Dorthe Wildenschild   +3 more
openaire   +1 more source