Results 51 to 60 of about 4,715 (162)

Combined147,146Sm‐143,142Nd constraints on the longevity and residence time of early terrestrial crust

Geochemistry, Geophysics, Geosystems, 2014
Primordial silicate differentiation controlled the composition of Earth's oldest crust. Inherited 142Nd anomalies in Archean rocks are vestiges of the mantle‐crust differentiation before ca. 4300 Ma. Here we report new whole‐rock 147,146Sm‐143,142Nd data
Antoine S. G. Roth, Bernard Bourdon, Stephen J. Mojzsis, John F. Rudge, Martin Guitreau, Janne Blichert‐Toft   +5 more
doaj   +1 more source

Recycled Oceanic Crust in the Source of the Intraplate Changbaishan‐Tianchi Volcano, China/North Korea

Geochemistry, Geophysics, Geosystems
Continental intraplate volcano is an ideal probe to unravel the composition and structure of the deep Earth. The intraplate Changbaishan‐Tianchi volcano was one of the most hazardous eruptions on the Earth's planet. The long‐term activity of this volcano
Yujie Liu, Chao Zhang, Hang Xu, Li‐Hui Chen, Bo Pan   +4 more
doaj   +1 more source

LATE NEOPROTEROZOIC RARE-METAL LEUCOGRANITE FROM THE KHARIUSIKHA MASSIF OF YENISEI RIGDE: GENESIS AND RELATIONSHIP TO MAGMATISM OF A LARGE IGNEOUS PROVINCE

Геодинамика и тектонофизика
The paper deals with the petrogeochemical composition and U-Pb (SHRIMP-II) age (753±6 Ma) of subalkaline leucogranites and syenites from the Khariusikha massif of the Yenisei Ridge, which contain rare-metal mineralization.
A. D. Nozhkin, O. M. Turkina
doaj   +1 more source

Attribution of the Langshan Tectonic Belt: Evidence from zircon U–Pb ages and Hf isotope compositions

Geoscience Frontiers, 2019
Abstract This study describes a previously unidentified Neoproterozoic mafic dyke emplaced in the northern flank of the Langshan Tectonic Belt. This dyke intruded into the micaquartz schist of the Zhaertaishan Group, and yielded an age of 908 ± 8 Ma.
Chuang Bao, Yuelong Chen, Xiangkun Zhu, Junxiang Zhao   +3 more
openaire   +1 more source

Isotopic and Geochemical Features of High-Hafnium Zircons of the Vasin-Mylk LCT Pegmatite, Kola Peninsula: Compositional Zoning and Crystallization Conditions

Geosciences
A comprehensive investigation was conducted on high-hafnium zircons from the LCT (Li-Cs-Ta) pegmatites of the Vasin-Mylk rare-metal deposit within the Fennoscandian Shield.
Ekaterina V. Kovalenko (Levashova), Nikolai M. Kudryashov, Sergey G. Skublov, Vladislav G. Kurichev, Xian-Hua Li   +4 more
doaj   +1 more source

Remelting of Ordovician migmatites and granites during Variscan high-grade metamorphism (Aar Massif, Central Alps, Switzerland) [PDF]

Swiss Journal of Geosciences
The remelting of felsic gneisses, migmatites and granite during a later orogenic cycle can produce rocks of different age with comparable field appearance, microstructure, mineralogical and chemical composition.
Urs Schaltegger, Alfons Berger, Jürgen Abrecht, Alexey Ulianov, Eliana Noroña Muñoz, Daniela Rubatto, Maria Ovtcharova, Agathe Martignier, Richard Spikings, Michael Wiederkehr   +9 more
doaj   +3 more sources

A database of detrital zircon U–Pb ages and Lu–Hf isotope of sediments in the South China Sea

Geoscience Data Journal
Source‐to‐sink analysis examines the effects of source areas and basin (sink) dynamics on the generation, transport, composition, distribution and deposition of sediment in modern and ancient sedimentary systems.
Yu Huang, Lisha Hu
doaj   +1 more source

Murzinka massive at the middle urals as an example of the interformational granite pluton: magmatic sources, geochemical zonality, peculiarities of formation

Литосфера, 2018
Murzinka massif is a sheet-like interformational body steeply deeping to the East with length about 6 km. Proterozoic metamorphic rocks of the predominantly granulite facies ( P = 5-6 kbar, T = 750-800°C) occur at the base of massif, and volcanic ...
German B. Fershtater, Nadezhda S. Borodina   +1 more
doaj   +1 more source

Using Soil Stable Isotopes, δ13c and δ15n, Properties for Interpreting Effects of Forest Understory Vegetation Removal on Nutrient Cycling

Düzce University Faculty of Forestry Journal of Forestry, 2019
Forest harvesting and understory vegetation management may disturb the ecological integrity of forest ecosystems. Abrupt change in plant composition in the stand also modifies the nutritional status of the site.
Oktay Yıldız
doaj  

Role of Magma Ocean Differentiation in the Formation and Long‐Term Preservation of Distinct Geochemical Domains Within the Deep Mantle

Geochemistry, Geophysics, Geosystems
We modeled the evolution of the terrestrial Magma Ocean using the short‐lived 182Hf‐182W isotope system (t1/2 = 8.9 Myr) in a multi‐reservoir early Earth. We start with a chondritic Earth at T0 = 4.567 Ga. Core segregates and attains its present‐day mass,
Seema Kumari, Ramananda Chakrabarti
doaj   +1 more source