Results 61 to 70 of about 66,575 (296)

Infinite magmatic bialgebras

Advances in Applied Mathematics, 2008
An infinite magmatic bialgebra is a vector space endowed with an n-ary operation, and an n-ary cooperation, for each n, verifying some compatibility relations. We prove a rigidity theorem, analogue to the Hopf-Borel theorem for commutative bialgebras: any connected infinite magmatic bialgebra is of the form $Mag^\infty(Prim H)$, where $Mag^\infty(V ...
openaire   +3 more sources

The lithospheric mantle and lower crust-mantle relationships under Scotland: a xenolithic perspective [PDF]

, 2011
In the British Isles the majority of volcanic rocks containing upper mantle and lower crustal xenoliths occur in Scotland. Most of the occurrences are of Carboniferous–Permian age.
Arai, B.G.J. Upton, Bonadiman, C. Bonadiman, Greenbaum, Griffin, H. Downes, Irving, Johnson, Kirstein, L.A. Kirstein, Larsen, Macdonald, McDonough, Menzies, P.G. Hill, Singh, T. Ntaflos   +17 more
core   +1 more source

Interplay Between Mechanical and Petrochemical Models on the Fluid Extraction From Subduction Zones

Journal of Metamorphic Geology, EarlyView.
ABSTRACT The breakdown of hydrous minerals during subduction results in a densification of the rocks, producing volume changes that can trigger fluid pressure fluctuations and hydrofracturing. These volume changes are controlled by the Clapeyron slope of the reaction and are quantified here using a macroscopic framework that integrates a zero ...
Thorsten Andreas Markmann, Pierre Lanari   +1 more
wiley   +1 more source

Water on Mars, With a Grain of Salt: Local Heat Anomalies Are Required for Basal Melting of Ice at the South Pole Today

Geophysical Research Letters, 2019
Recent analysis of radar data from the Mars Express spacecraft has interpreted bright subsurface radar reflections as indicators of local liquid water at the base of the south polar layered deposits (SPLD). However, the physical and geological conditions
Michael M. Sori, Ali M. Bramson
doaj   +1 more source

Petrogenesis and Geodynamic Implications of Late Triassic Mogetong Adakitic Pluton in East Kunlun Orogen, Northern Tibet: Constraints from Zircon U–Pb–Hf Isotopes and Whole-Rock Geochemistry

Frontiers in Earth Science, 2022
Adakites or adakitic rocks usually show special geochemical signatures and are petrological probes to reveal the tectono–magmatic evolutionary history of paleo–orogenic belts. Here, we present a comprehensive study on the zircon U–Pb geochronology, whole-
Jie Gan, Jie Gan, Fuhao Xiong, Fuhao Xiong, Fuhao Xiong, Qianru Xiao, Qianru Xiao, Wei Wang, Dongdong Yan   +8 more
doaj   +1 more source

Isotope geochemistry and petrogenesis of peralkaline Middle Miocene ignimbrites from central Sonora: relationship with continental break-up and the birth of the Gulf of California [PDF]

, 2008
Middle Miocene peralkaline ignimbrites constitute a specific geodynamic marker of the early stage of opening of the Gulf of California, preserved either in central Sonora or the Puertecitos area, in Baja California.
Amortegui, Andrea, Bosch, Delphine, Brunet, Pierre, Demant, Alain, Lapierre, Henriette, Paz Moreno, Francisco A., Stock, Joann M., Vidal Solano, Jesús R.   +7 more
core   +3 more sources

Exploring the Gravimetric and Geochronological Links in Ancient Terranes of the São Francisco Craton and Borborema Province, NE‐Brazil

Terra Nova, EarlyView.
ABSTRACT Deep crustal fragments and structural lineaments identified through satellite gravity data provide evidence for the extension of the reworked ancient basement of the Central African Block into the northern São Francisco Craton and southern Borborema Province.
Douglas Teixeira Martins, Wagner da Silva Amaral, Felipe Holanda dos Santos, Evilarde Uchôa Filho   +3 more
wiley   +1 more source

Giant Porphyry Copper Deposits Caused by a Slab Jamming in the Mantle Transition Zone

Terra Nova, EarlyView.
ABSTRACT Two giant porphyry copper deposits in the Southern Central Andes formed during the Miocene–Pliocene transition when a bend in the subducting Juan de Fernández hotspot chain jammed in the mantle transition zone, causing mega‐scale slab‐kinking. This geometry implies mechanical resistance that caused East–West compression and eventually a thrust‐
Nipaporn Nakrong, Marnie Forster, Wim Spakman, Hielke Jelsma, Francois Gaboury, Gordon Lister   +5 more
wiley   +1 more source

Dating C/S Structures in Syntectonic Granites by In Situ Rb‐Sr Analyses on Muscovite

Terra Nova, EarlyView.
ABSTRACT The interplay of crystallisation, deformation and fluid–rock interactions makes deciphering geochronological information complex in syntectonic granites. In this study, we apply in situ Rb‐Sr analyses to selected samples from the Questembert Variscan syntectonic granite in Western France, which was emplaced along the South Armorican Shear Zone
Philippe Boulvais, Romain Tartèse
wiley   +1 more source

Forearc tectonics and volcanism during the Devonian–Carboniferous evolution of the North Patagonian segment, southern Chile (41,3°S)

Frontiers in Earth Science, 2022
Late Paleozoic to early Mesozoic subduction complexes formed during the evolution of southwestern Gondwana and extensively crop out along the Chilean continental margin.
C. Palape, C. Palape, P. Quezada, J. Bastías, J. Bastías, F. Hervé, F. Hervé, T. Reyes, T. Reyes, M. Veas, F. Vildoso, M. Calderón, T. Theye, F. Fuentes, M. Chiaradia   +14 more
doaj   +1 more source