Results 51 to 60 of about 798 (184)

Coesite Discovery in Eclogites Confirms UHP Metamorphism in the Orlica‐Śnieżnik Dome (SW Poland)

Journal of Metamorphic Geology, Volume 44, Issue 3, Page 200-225, April 2026.
ABSTRACT Eclogite lenses are exposed within the orthogneiss‐dominated core of the Orlica‐Śnieżnik Dome in the Sudetes, which forms the northeastern margin of the Bohemian Massif (Variscan Belt of Central Europe). The presence of coesite inclusions in garnet and omphacite confirms that these eclogites underwent ultrahigh‐pressure metamorphism.
Małgorzata Nowak, Lucie Tajčmanová, Marcin Dąbrowski, Iris Buisman, Jacek Szczepański   +4 more
wiley   +1 more source

Metamorphism of Late Neoproterozoic-Early Cambrian Schists in Southwest of Zanjan from the Soltanieh Belt in Northwest of Iran [PDF]

Journal of Sciences, Islamic Republic of Iran, 2012
Late Neoproterozoic-Early Cambrian schists have been occurred in southwest of Zanjan city from the Soltanieh belt. The Soltanieh belt in northwest of Iran is uplifted basement of Precambrian-Paleozoic in main central Iran zone and includes outcrops of ...
J. Izadyar
doaj  

Whole-rock Geochemistry and Mineral Chemistry of the Late Cretaceous Dacites in SW Sabzevar: constrain on their origin and tectonic setting [PDF]

پترولوژی, 2018
A thick sequence of Upper Cretaceous volcano-sedimentary rocks are cropped out on the northern edge of Central Iran, southwest of Sabzevar. The volcanic rocks are dacite/rhyolite and are associated with pyroclastic rocks, including agglomerate, breccia ...
Habibollah Ghasemi, Zakie Kazemi, Fardin Mousivand, William Griffin   +3 more
doaj   +1 more source

Mantle Xenolith Evidence for Lithospheric Thinning and Metasomatic Modification Beneath the Eastern Fiji Plateau: Implications for Samoan Plume Supply, Intraplate Volcanism, and Orocline Formation

New Zealand Journal of Geology and Geophysics, Volume 69, Issue 1, March 2026.
We provide petrographic and geochemical characterisation of mantle xenoliths from Koro Island, eastern Fiji. Several lherzolite xenoliths display spinel–pyroxene symplectite textures, including preserved former grain boundaries, consistent with garnet breakdown that we attribute to thinning of a preexisting garnet‐facies lithospheric mantle beneath ...
Natasha Barrett, Stephen T. Johnston, Neil N. Kumar, Holger Sommer, D. Graham Pearson   +4 more
wiley   +1 more source

A clinopyroxene-basalt geothermobarometry perspective of Columbia Plateau (NW-USA) Miocene magmatism

, 2005
The origin of NW-USA Columbia River Basalt Group Miocene magmatism and its relation to tectonism has been widely debated and is still open to study. We investigated the pre-eruptive evolution of the magmas, to constrain pressures and temperatures of the ...
Reidel, SP, Caprarelli, G
core   +1 more source

Rapid Transition From High‐Pressure Metamorphism to Exhumation Driven by Orogen‐Parallel Extensional Shearing (Adula Unit, Eastern Central Alps)

Tectonics, Volume 45, Issue 2, February 2026.
Abstract In the Central Alps, the Adula unit exposes high‐ and ultra‐high‐pressure (HP‐UHP) metamorphic rocks, providing key insights into the subduction and exhumation dynamics of the former distal European margin. We investigate the San Bernardino Shear Zone (SBSZ), a top‐to‐the‐east extensional shear zone developed within orthogneiss and paragneiss ...
C. Montemagni, R. Monti, N. Malaspina, P. Vannucchi, S. Zanchetta   +4 more
wiley   +1 more source

Geological-structural mapping and geocronology of shear zones: A methodological proposal

Boletín Geológico, 2021
The deformation registered in rocks in the field can be characterized based on the structures preserved in outcrops, which can related be to wide discontinuity zones named faults and shear zones.
Anny Julieth Forero Ortega, Julián Andrés Lopéz Isaza, Nelson Ricardo López Herrera, Mario Andrés Cuéllar Cárdenas, Lina Maria Cetina Tarazona, Luis Miguel Aguirre Hoyos   +5 more
doaj   +1 more source

Origin of Silicic Magmas at Kibblewhite Volcano: Implications for Bimodal Volcanism in the Kermadec Arc

Island Arc, Volume 35, Issue 1, January/December 2026.
ABSTRACT This study investigates the origin of silicic magmas at the Kibblewhite Volcano in the Kermadec arc. Two alternative differentiation pathways are evaluated: fractional crystallization of primary basaltic magmas producing low‐Mg andesites, and fractional crystallization of primary andesitic magmas represented by magnesian andesites.
Yasuhiro Hirai, Yoshihiko Tamura
wiley   +1 more source

Mineral chemistry and geothemobarometry of mantle harzburgites in the Eastern Metamorphic Complex of Khoy ophiolite -NW Iran

Journal of Economic Geology, 2017
Introduction Khoy ophiolite at the global scale is in the middle part of the Alp-Himalaya orogenic belt and it is extended over 3900 Km2 which indicates remnant Neotethys oceanic lithosphere in the Mesozoic era (Kananian et al., 2010). In this paper, in
Morovvat Faridazad
doaj   +1 more source

Combining Petrology and Seismology to Unravel the Plumbing System of a Typical Arc Volcano: An Example From Marapi, West Sumatra, Indonesia

Geochemistry, Geophysics, Geosystems, 2021
Marapi in Sumatra is characterized by frequent short‐lived explosions and small eruptions (Volcanic Explosivity Index 1–2) and in the past 250 years, the volcano has erupted >60 times.
D. Nurfiani, X. Wang, H. Gunawan, H. Triastuty, D. Hidayat, S. J. Wei, B. Taisne, C. Bouvet de Maisonneuve   +7 more
doaj   +1 more source