Results 11 to 20 of about 5,319 (257)

The Late- Cretaceous volcanic rocks from Talesh area (western Alborz): chemical variation, crystallization condition, hygrometry and tectonic setting [PDF]

open access: yesپترولوژی, 2020
In the Talesh area (western Alborz), a thick sedimentary- volcanic association formed in a littoral- deltaic environment during the Late Cretaceous. The extrusives comprise volcanoclastics (tuffs), lava flows (pillow and massive) and basic dykes.
Khadijeh Amani   +3 more
doaj   +1 more source

Mineralogy and thermobarometry of metamorphic basement from the Kabul Block (Eastern Afghanistan) [PDF]

open access: yesپترولوژی, 2019
The cratonic basement in the Kabul district is dominated by gneiss, migmatite, schist, and amphibolite and is characterized by extensive outcrops.  Orthopyroxene and garnet are the index minerals of some of the gneisse, hence, they are considered as ...
Ali Mohammad Ramezani   +3 more
doaj   +1 more source

Mineral chemistry, Thermobarometry, Geochemistry and tectonic setting of Tertiary andesitic lavas in the Shourestan area (west of Sarbisheh), Southern Khorasan

open access: yesJournal of Economic Geology, 2022
In the Shourestan area, 14 kilometers west of Sarbisheh city, in South Khorasan province, volcanic rocks with pyroxene-andesite composition belonging to Eocene-Oligocene are exposed.
Seyyed Saeid Mohammadi   +3 more
doaj   +1 more source

Metamorphic evolutions of high-pressure low-temperature units from ophiolitic mélange of North Soghan (NE Hajiabad, Hormozgan) [PDF]

open access: yesپترولوژی, 2021
The Seghin metamorphic complex of ophiolitic mélange from the north Soghan, composed of metamorphic suites varying in protolith and metamorphic grade. The rock units of this complex have been metamorphosed under PT conditions of pumpellyite- actinolite ...
akbar ahmadvand   +3 more
doaj   +1 more source

Old/New Subduction Zone Paradigms as Seen From the Cascades

open access: yesFrontiers in Earth Science, 2020
This paper briefly reviews the magmatic manifestations of volcanic arcs and aspects of how such magmas form. Common concepts about “how subduction zones work” are reassessed—with particular emphasis on the atypical Cascades volcanic arc.
William P. Leeman
doaj   +1 more source

Determination of P-T and tectonic setting of Ghaleh Yaghmesh plutonic complex (west of Yazd province) by using of mineral chemistry [PDF]

open access: yesپترولوژی, 2017
The Ghaleh Yaghmesh plutonic massif is located the westernmost part of Yazd province and in the central part of the Urumieh – Dokhtar magmatic arc (UDMA).
Bahareh Fazeli   +2 more
doaj   +1 more source

Mantle and Crustal Xenoliths in a Tephriphonolite From La Palma (Canary Islands): Implications for Phonolite Formation at Oceanic Island Volcanoes

open access: yesFrontiers in Earth Science, 2022
The occurrence of mantle-derived peridotite xenoliths in phonolitic melts is a rare phenomenon, and is commonly ascribed to a mantle origin of the phonolite.
Andreas Klügel   +2 more
doaj   +1 more source

Paleozoic high-temperature metamorphism and deformation related to Proto-Tethys closure and Paleo-Tethys opening in the north of Central-East Iranian Microcontinent, based on the mineralogy of Airakan metagranite [PDF]

open access: yesپترولوژی, 2023
Granites are one of the most abundant rock groups formed the continental crust, and are considered for investigating the temperature conditions of their formation and metamorphism. Thus, they are a unique window to magmatism and tectonic evolution of the
Nargess Shirdashtzadeh
doaj   +1 more source

Variations in the P‐T‐t of Deformation in a Crustal‐Scale Shear Zone in Metagranite

open access: yesGeochemistry, Geophysics, Geosystems, 2020
Deformation in crustal‐scale shear zones occurs over a range of pressure‐temperature‐time (P‐T‐t) conditions, both because they may be vertically extensive structures that simultaneously affect material from the lower crust to the surface, and because ...
T. K. Cawood, J. P. Platt
doaj   +1 more source

Sulfur loss from subducted altered oceanic crust and implications for mantle oxidation [PDF]

open access: yes, 2020
© The Author(s), [year]. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Walters, J. B., Cruz-Uribe, A. M., & Marschall, H. R.
Cruz‐Uribe, Alicia M.   +2 more
core   +1 more source

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