Results 71 to 80 of about 1,482 (183)

Earth’s past and present mantle oxygen fugacity

Nature Reviews Earth & Environment
Oxygen is the most abundant element in Earth’s mantle. Oxygen fugacity (fO2), which quantifies the availability of oxygen to mediate oxidation–reduction reactions, affects important mantle processes, such as depth of melting, extraction of volatiles to the atmosphere, crustal composition and ore body generation.
Elizabeth Cottrell, Dante Canil, Charles Langmuir, Katy A. Evans, Fabrice Gaillard   +4 more
openaire   +2 more sources

Thermodynamic Reassessment of the FeO–Fe2O3–MgO–SiO2 System Integrated With Experimental Phase Equilibria Studies

Journal of the American Ceramic Society, Volume 109, Issue 7, July 2026.
ABSTRACT Phase equilibria studies were undertaken on the FeO–FeO1.5–MgO and FeO–FeO1.5–MgO–SiO2 systems using equilibration and quenching technique followed by the electron probe x‐ray microanalysis (EPMA). The primary phase fields of spinel (Fe,Mg)Fe2O4, monoxide (Mg,Fe)O1+x, olivine (Mg,Fe)2SiO4, pyroxene (Mg,Fe)SiO3 (proto, ortho, and clino ...
Igor Babaian, Maksym Shevchenko, Evgenii Nekhoroshev, Evgueni Jak   +3 more
wiley   +1 more source

Oxygen Fugacity of Global Ocean Island Basalts

Geochemistry, Geophysics, Geosystems
AbstractMantle plumes contain heterogenous chemical components and sample variable depths of the mantle, enabling glimpses into the compositional structure of Earth's interior. In this study, we evaluated ocean island basalts (OIB) from nine plume locations to provide a global and systematic assessment of the relationship between fO2 and He‐Sr‐Nd‐Pb‐W ...
Lori N. Willhite, Ricardo Arevalo, Philip Piccoli, John C. Lassiter, Devin Rand, Matthew G. Jackson, James M. D. Day, Robert W. Nicklas, Marek Locmelis, Thomas J. Ireland, Igor S. Puchtel   +10 more
openaire   +2 more sources

Origin of the RNA World in Cold Hadean Geothermal Fields Enriched in Zinc and Potassium: Abiogenesis as a Positive Fallout from the Moon-Forming Impact?

Life
The ubiquitous, evolutionarily oldest RNAs and proteins exclusively use rather rare zinc as transition metal cofactor and potassium as alkali metal cofactor, which implies their abundance in the habitats of the first organisms.
Armen Y. Mulkidjanian, Daria V. Dibrova, Andrey Y. Bychkov   +2 more
doaj   +1 more source

Variable Sr Diffusion and Implications for Rb–Sr Biotite Geochronology

Journal of Metamorphic Geology, Volume 44, Issue 6, Page 417-439, July 2026.
ABSTRACT The rubidium–strontium (Rb–Sr) system has a long pedigree as a geochronological tool that relies on the application of an isochron approach. In particular, biotite contains strongly radiogenic Rb–Sr isotopes, and thus can yield meaningful crystallisation or cooling ages via this approach. However, the response of the Rb–Sr system in biotite to
Riley Rohrer, Christopher L. Kirkland, Hugo Olierook, Tim Johnson, Katy Evans   +4 more
wiley   +1 more source

TRANSPARENT CONDUCTING OXIDE SYNTHESIS OF ALUMINIUM DOPED ZINC OXIDES BY CHEMICAL COPRECIPITATION

Avances en Ciencias e Ingeniería, 2013
Aluminium doped zinc oxides (AZO) are promising replacements for tin doped indium oxides (ITO) but thin films show a wide range of physical properties strongly dependent on deposition process conditions.
Silvia Maioco, Claudia Vera, Natan Rajchenberg, Ricardo Aragón   +3 more
doaj  

Controlling factors of the metallogenic intensity in Han–Xing-type skarn iron deposits: insights from trace elements in magmatic magnetite

Frontiers in Earth Science
The Handan–Xingtai region is one of the important production areas of skarn-type iron deposits in China. The magmatic rocks associated with iron mineralization in this region are predominantly intermediate-basic and intermediate-felsic in composition ...
Jin Yanan, Jin Yanan, Wang Denghong, Zhang Juquan, Zhang Juquan, Zhang Long   +5 more
doaj   +1 more source

Magnetic susceptibility of Variscan granite-types of the Spanish Central System and the redox state of magma

Geologica Acta, 2017
Magnetic susceptibility (MS) has been measured in Variscan granites from central Spain. They yield values in the order of 15 to 180μSI units for S- and I-type granites, indicating that both types belong to the ilmenite series.
C. VILLASECA, V.C. RUIZ-MARTÍNEZ, C. PÉREZ-SOBA   +2 more
doaj  

Geological characteristics of neoproterozoic motianling granitic pluton hosting uranium mineralization in North Guangxi, China: Insights from biotite chemistry

Frontiers in Earth Science
The Motianling pluton represents a characteristic U-bearing granite pluton in South China. Biotite serves as an indicator for the mineralization of metals such as Cu, Sn, and W in granite. Previous studies have extensively investigated the U metallogenic
Pailong Luo, Pailong Luo, Chunying Guo, Chunying Guo, Chunying Guo, Qiaohui Pi, Qiaohui Pi, Ning Wang, Ning Wang, Naiyuan Liu, Naiyuan Liu, Naiyuan Liu   +11 more
doaj   +1 more source

Geochemical indicators for cobalt-rich skarn exploration: constraints from the Pusangguo granodiorite (Gangdese) on geochemistry, zircon U-Pb geochronology and Hf-Nd-Sr isotopes

Frontiers in Earth Science
The Pusangguo skarn-type copper-polymetallic deposit in the Gangdese metallogenic belt hosts economic cobalt mineralization. An integrated study of petrography, zircon U-Pb geochronology, whole-rock geochemistry, and Sr–Nd–Hf isotopes indicates the ore ...
Zhaxi Pubu, Qiong Ci, Fuzhi Gong, Nan Chao   +3 more
doaj   +1 more source