Results 61 to 70 of about 181,228 (320)

Peixe Zircon as a Quality Control Reference Material in U‐Pb Geochronology by LA‐ICP‐MS

Geostandards and Geoanalytical Research, EarlyView.
Key Points Peixe#0 zircon was characterised for U‐Pb geochronology using CA‐ID‐TIMS, SIMS and a long‐term LA‐ICP‐MS data set. The consistent results establish Peixe#0 as a reference material for U‐Pb quality control. Trace element heterogeneity requires careful, CL‐guided spot selection.
Margareth Sugano Navarro, Erica Martini Tonetto, Elson P. Oliveira, Mauricio Ibañez‐Mejia, Cristina Talavera, Neal J. McNaughton, Jacinta Enzweiler, Michael Wiedenbeck   +7 more
wiley   +1 more source

NATO i Zapadni Balkan u uvjetima novih sigurnosnih izazova

Međunarodne Studije, 2014
U skladu sa zaključcima donesenim na NATO-ovom samitu u Walesu, posebno s onim kako će NATO ostati „temeljem naše kolektivne obrane“, zemlje Zapadnog Balkana svjesne su važnosti pripadanja transatlantskom sigurnosnom okruženju, vođenom od strane NATO-a ...
Monika Begović
doaj  

Towards a Generalized Cayley–Dickson Construction through Involutive Dimagmas

Mathematics
A generalized construction procedure for algebraic number systems is hereby presented. This procedure offers an efficient representation and computation method for complex numbers, quaternions, and other algebraic structures.
Nelson Martins-Ferreira, Rui A. P. Perdigão   +1 more
doaj   +1 more source

Modeling Viscosity of Volcanic Melts With Artificial Neural Networks

Geochemistry, Geophysics, Geosystems, 2022
Viscosity is of great importance in governing the dynamics of volcanoes, including their eruptive style. The viscosity of a volcanic melt is dominated by temperature and chemical composition, both oxides and water content.
D. Langhammer, D. Di Genova, G. Steinle‐Neumann   +2 more
doaj   +1 more source

Timing of Metamorphism and Deformation in the Neoarchean Quetico Metasedimentary Belt, Superior Craton, Constrained by Garnet Trace‐Element Mapping and Lu–Hf Geochronology

Journal of Metamorphic Geology, EarlyView.
ABSTRACT The Quetico subprovince of the Superior Province is among the largest metasedimentary belts globally and provides evidence of tectonic processes at play during the final stages of Archean cratonization. Although previous studies have shown that deformation and metamorphism of the 2.7‐Ga turbiditic protolith resulted in regional subvertical ...
Adrian G. Rehm, Antoine Godet, Doug Tinkham, Carl Guilmette, Matthijs A. Smit   +4 more
wiley   +1 more source

Thermal Buffering, Heat Advection and Crustal Thinning in the Ryoke Metamorphic Complex, Yanai, Southwest Japan

Journal of Metamorphic Geology, EarlyView.
ABSTRACT The metamorphic zoning and geothermobarometry of the Ryoke metamorphic complex in the Yanai area, southwest Japan, show that its thermobaric structure was buffered by the dehydration melting of biotite. The temperatures over most of the area covered by the three high‐grade zones (8.5‐ to 19.0‐km depth) are consistent with those of the ...
Takeshi Ikeda, Kazuhiro Miyazaki, Yu Sugawara, Risa Hayashi   +3 more
wiley   +1 more source

Petrography and mineral chemistry of Northeast Africa 053—A remnant of Martian crystal mush

Meteoritics &Planetary Science, EarlyView.
Abstract In Earth's igneous systems, crystal mushes, crystal‐rich frameworks permeated by silicate melt, represent a common and fundamental stage in the evolution of magma bodies. However, whether crystal mushes occur within Martian igneous systems and play a comparable role is unknown. Here, we present a comprehensive petrography and mineral chemistry
Xhonatan Shehaj, Eleonora Ammannito, Giovanni Pratesi   +2 more
wiley   +1 more source

Magmatic Densities Control Erupted Volumes in Icelandic Volcanic Systems

Frontiers in Earth Science, 2018
Magmatic density and viscosity exert fundamental controls on the eruptibility of magmas. In this study, we investigate the extent to which magmatic physical properties control the eruptibility of magmas from Iceland's Northern Volcanic Zone (NVZ).
Margaret Hartley, Margaret Hartley, John Maclennan   +2 more
doaj   +1 more source

A Numerical Treatment of Melt/Solid Segregation: Size of the Eucrite Parent Body and Stability of the Terrestrial Low-Velocity Zone [PDF]

, 1978
Crystal sinking to form cumulates and melt percolation toward segregation in magma pools can be treated with modifications of Stokes' and Darcy's laws, respectively.
Hays, James F., Stolper, Edward M., Walker, David   +2 more
core   +1 more source

Microspherules Formed by Lightning Strikes

Meteoritics &Planetary Science, EarlyView.
Abstract Natural microspherules are formed by high‐temperature processes and are present throughout the geologic record to the present day. We report the discovery of large numbers of microspherules recovered from a rock pavement in the Pilbara region, Western Australia.
M. R. Boyd, M. J. Genge, A. G. Tomkins
wiley   +1 more source