Results 41 to 50 of about 2,046 (219)

U-Pb (SHRIMP-RG) age of zircon from rare-metal (Li, Cs) pegmatites of the Okhmylk deposit of the Kolmozero-Voron’ya greenstone belt (northeast of the Fennoscandian shield)

open access: yesЗаписки Горного института, 2022
The results of isotopic and geochronological study of zircon from rare-metal pegmatites of the Okhmylk deposit are presented. There were no reliable data on the age of lepidolite-spodumene-pollucite pegmatites of this and the other deposits spatially ...
Nikolay M. Kudryashov   +5 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

Enhanced diffusion of Uranium and Thorium linked to crystal plasticity in zircon

open access: yesGeochemical Transactions, 2006
The effects of crystal-plasticity on the U-Th-Pb system in zircon is studied by quantitative microstructural and microchemical analysis of a large zircon grain collected from pyroxenite of the Lewisian Complex, Scotland. Electron backscatter diffraction (
Reddy Steven M   +2 more
doaj   +1 more source

Sensitive High Resolution Ion Microprobe (SHRIMP IIe/MC) of the Institute of Geosciences of the University of São Paulo, Brazil: analytical method and first results [PDF]

open access: yesGeologia USP. Série Científica, 2014
This paper presents the characteristics of the high resolution secondary ion mass spectrometer coupled with an Ion Micro - probe (SHRIMP IIe/MC), installed at the Institute of Geosciences of the University of São Paulo (IGc-USP), as well as the ...
Kei Sato   +6 more
doaj   +1 more source

U–Pb zircon ages for post-Variscan volcanism in the Ligurian Alps(Northern Italy)

open access: yesJournal of the Geological Society, 2009
Abstract: Ages of Permian volcanic rocks from the Ligurian Briançonnais domain (Western Italian Alps) have been determined by laser ablation inductively coupled plasma mass spectrometry U–Pb dating of zircon. Three major volcanic units yielded zircons that were dated: calc-alkaline rhyolites (285.6 ± 2.6 Ma), andesites (with ...
DALLAGIOVANNA G   +4 more
openaire   +4 more sources

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

A Geologic Si‐O‐C Pathway to Incorporate Carbon in Silicates

open access: yesGeophysical Monograph Series, Page 47-54., 2020

This book is Open Access. A digital copy can be downloaded for free from Wiley Online Library.

Explores the behavior of carbon in minerals, melts, and fluids under extreme conditions

Carbon trapped in diamonds and carbonate-bearing rocks in subduction zones are examples of the continuing exchange of substantial carbon ...
Alexandra Navrotsky   +2 more
wiley  

+1 more source

A revised Ordovician age for the Miranda do Douro orthogneiss, Portugal. Zircon U-Pb ion-microprobe and LA-ICPMS dating

open access: yesGeologica Acta, 2006
The Miranda do Douro orthogneiss was believed to be the oldest magmatic rock of the Central Iberian Zone, on the base of a U-Pb discordia upper intercept of 618 ± 9 Ma.
F. BEA   +3 more
doaj   +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

Turning Trash Into Treasure: Extracting Meaning From Discordant Data via a Dedicated Application

open access: yesGeochemistry, Geophysics, Geosystems
Zircon U–Pb geochronology is a vital tool for dating geological events, but interpreting discordant zircon ages—often the result of Pb loss due to fluid‐rock interactions—remains challenging.
Lucy M. Mathieson   +2 more
doaj   +1 more source

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