Results 41 to 50 of about 2,562 (192)

Geothermobarometry using minerals at non-equilibrium: a corona example

European Journal of Mineralogy, 2001
A simple extension of geothermobarometric technique is developed, from the usual case of assumed equilibrium among all minerals, to layered coronas with gradients of chemical potential. For reactions among end-members in the minerals, instead of the assumption of zero affinity (-δG) = 0, (-δG) ratios are used.
John R. Ashworth, Valentin S. Sheplev, Vladimir V. Khlestov, Vyatcheslav A. Ananyev   +3 more
openaire   +1 more source

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

Deep lithospheric dynamics beneath the Sierra Nevada during the Mesozoic and Cenozoic as inferred from xenolith petrology [PDF]

, 2001
Peridotite xenoliths erupted in late Miocene basalts (~8 Ma) in the central Sierra Nevada sample a lithosphere that is vertically stratified in terms of age and thermal history.
Brimhall, George H., Jr., Lee, Cin-Ty, Rudnick, Roberta L.   +2 more
core   +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  

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

MODELLING HEAT GENERATION DURING FRICTION AND VISCOPLASTIC DEFORMATION BASED ON THE EXAMPLE OF THE YENISEI SHEAR ZONE (EASTERN SIBERIA)

Геодинамика и тектонофизика, 2021
Deviations of the РТ parameters from the background values, corresponding to the lithostatic pressure and the standard geotherm characteristic of the neighboring crustal blocks of the Yenisei Ridge, were recorded by geothermobarometry in the zones of ...
O. P. Polyansky, A. V. Babichev, A. N. Semenov, V. V. Reverdatto   +3 more
doaj   +1 more source

Refinement of geothermobarometry for cordierite granulites

Journal of Earth System Science, 1993
Refined geothermobarometers are presented for cordierite granulites. The refinement was achieved by using internally consistent thermodynamic datasets. Improved calibrations have been demonstrated for a number of granulite areas. Also, the usefulness of the improved geobarometer in identifying decompression paths has been discussed.
openaire   +2 more sources

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

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