Results 51 to 60 of about 11,494 (230)

El volcanismo jurásico superior de la Formación Río Damas-Tordillo (33°-35,5°S): antecedentes su sobre petrogénesis, cronología, proveniencia e implicancias tectónicas [PDF]

open access: yes, 2014
Los depósitos continentales y volcánicos de la Formación Rio Damas-Tordillo, Jurásico Superior, representan un período restringido de sedimentación continental dentro del registro mayormente marino de la Cuenca Neuquina.
Calderón, Sergio   +7 more
core   +2 more sources

Polymict melt‐bearing breccia dikes in the Morokweng impact structure formed by slip‐induced mechanical mixing of pseudotachylite and cataclasite along large‐displacement impact faults

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract A core drilled through shocked and faulted Archean granitoid gneisses and dolerites in the eroded peak ring of the 70–80 km diameter Morokweng impact structure intersects multiple centimeter‐ to meter‐wide clastic‐matrix breccias containing a polymict clast population of lithic and mineral clasts and altered, millimeter‐ to centimeter ‐size ...
Roger L. Gibson   +3 more
wiley   +1 more source

Ductile Extrusion Triggered by Continental Collision in NE Brazil

open access: yesTerra Nova, EarlyView.
ABSTRACT The Borborema Province in northeastern Brazil hosts one of the world's largest strike‐slip shear zone networks, active during the late Neoproterozoic assembly of West Gondwana. Whether these shear zones initiated during active continental collision or as a post‐orogenic response to far‐field stresses remains debated.
L. R. Tesser   +6 more
wiley   +1 more source

Igneous Layering, Fractional Crystallization and Growth of Granitic Plutons: the Dolbel Batholith in SW Niger [PDF]

open access: yes, 2011
This study reassesses the development of compositional layering during the growth of granitic plutons, with emphasis on fractional crystallization and its interaction with both injection and inflation-related deformation.
Pupier, E.   +3 more
core   +4 more sources

TITANITE OF THE VISHNEVOGORSKY ALKALINE COMPLEX (South Ural) [PDF]

open access: yesМинералогия, 2019
Titanite CaTi(SiO4 )O is a common accessory mineral of alkaline rocks and pegmatites of the Vishnevogorsky alkaline complex, South Urals. It occurs in many magmatic assemblages, is found in some metasomatites, underwent deformation and recrystallization.
V.A. Popov
doaj  

Neoproterozoic ultramafic and mafic magmatism in the Eastern Cordillera of the central peruvian Andes: the Tapo Massif [PDF]

open access: yes, 2010
A highly dismembered assemblage of ultramafic and mafic rocks is exposed in the Eastern Cordillera of the Central Peruvian Andes, extending along a discontinuous NW-SE belt over some 250 km between 12° and 9° S of latitude.
Acosta, Jorge   +4 more
core   +2 more sources

Detrital zircon SHRIMP U-Pb age study of the Cordillera Darwin Metamorphic Complex of Tierra del Fuego : sedimentary sources and implications for the evolution of the Pacific margin of Gondwana [PDF]

open access: yes, 2010
The Cordillera Darwin Metamorphic Complex in the southernmost Andes includes a basement of probable Palaeozoic age, a mid-Jurassic and younger volcano-sedimentary cover, and a suite of Jurassic granites, all of which were jointly metamorphosed during the
Calderon, M.   +6 more
core   +1 more source

Zircon dissolution in a ductile shear zone, Monte Rosa granite gneiss, northern Italy [PDF]

open access: yes, 2008
The sizes, distributions and shapes of zircon grains within variably deformed granite gneiss from the western Alps have been studied. Zircon shows numerous indicators of a metamorphic response in both the host gneiss and a 5 cm wide continuous ductile ...
Dal Piaz   +14 more
core   +1 more source

Progressively Fenitised Schist and Carbonatitic Clasts From a Metasomatic Aureole Beneath the Alkalic Dunedin Volcano, Otago, New Zealand

open access: yesNew Zealand Journal of Geology and Geophysics, Volume 69, Issue 2, June 2026.
Clasts of albite‐porphyroblastic quartzofeldspathic schist, derived from the Otago Schist basement, occur within the Port Chalmers Breccia, a diatreme at the centre of the Dunedin stratovolcano, New Zealand. Schists have undergone varying degrees of replacement reactions (at temperatures of 300° to >500°C) producing hornfelses, with Ca‐ and K‐enriched ...
Alan F. Cooper
wiley   +1 more source

MINERALOGICAL-PETROGRAPHIC FEATURES OF SYENITIC MIGMATITES OF THE ILMENOGORSKY MIASKITE BLOCK (SOUTH URALS) [PDF]

open access: yesМинералогия, 2019
Syenitic migmatites of the contact of the Ilmenogorsky miaskite block are characterized by high (>500 ppm) contents of REEs, which are mainly hosted in fluorapatite and titanite of the leucosome.
А.B. Nemov   +3 more
doaj   +1 more source

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