Results 41 to 50 of about 4,348 (222)

K-Ar geochronology for hydrothermal K-feldspar within plagioclase in a granitic pluton: constraints on timing and thermal condition for hydrothermal alteration

Heliyon, 2021
This study presents the K-Ar geochronology for hydrothermal K-feldspar in plagioclase alteration, including methodology and application to the Toki granite, in central Japan.
Takashi Yuguchi, Koshi Yagi, Eiji Sasao, Tadao Nishiyama   +3 more
doaj   +1 more source

Geochemical and Geological Investigation of Skarn‐Type Pb–Zn Mineralization in Hastanetepe (Balya‐Balıkesir, Türkiye): An Approach Based on Fluid Inclusions, Sulphur Isotopes and Geochemical Data

Geological Journal, EarlyView.
Integrated petrographic, mineralogical and geochemical data from the Hastanetepe Pb–Zn deposit (Balya, Türkiye) reveal multi‐stage hydrothermal alteration and a magmatic sulphur source. Fluid inclusion and sulphur isotope results indicate a complex fluid evolution responsible for skarn‐type Pb–Zn mineralization along limestone–dacite contacts ...
Esra Ünal‐Çakır
wiley   +1 more source

Oriented Magnetite Inclusions in Plagioclase: Implications for the Anisotropy of Magnetic Remanence

Geochemistry, Geophysics, Geosystems, 2022
Micron to sub‐micron sized ferromagnetic inclusions in rock forming silicate minerals may give rise to particularly stable remanent magnetizations. When a population of inclusions have a preferred crystallographic or shape orientation in a rock, the ...
O. Ageeva, G. Habler, S. A. Gilder, R. Schuster, A. Pertsev, O. Pilipenko, G. Bian, R. Abart   +7 more
doaj   +1 more source

Geochemistry and Geochronology of Magmatic Rocks in Southwestern and Northeastern Cambodia: Implications for the Tectonic Evolution and Metallogenesis of the Loei Fold Belt

Geological Journal, EarlyView.
The composition of intrusive rocks suggests that the magma was likely generated in a subduction‐related setting. The arc crustal thickness in the Phnom Sro Ngam and Halo Prospects was probably < 40 km during emplacement. Zircon U–Pb age range indicates a correlation with Loei Fold Belt magmatic activity.
Sirisokha Seang, Khin Zaw, Kakda Kret, Ivan Belousov, Kotaro Yonezu, Koichiro Watanabe, Charles Makoundi   +6 more
wiley   +1 more source

APG: An Efficient Software Program for Amp-Pl Thermobarometry Based on Graphical Method [PDF]

Journal of Sciences, Islamic Republic of Iran, 2011
Geothermobarometry equations are based on thermodynamic principles and appear in single or multi-variant functions. The number of variants for a specific composition or reaction usually is reduced into 2 involving temperature (T) and pressure (P).
M. Sayari
doaj  

Late Pleistocene Volcanic Rocks From Tengchong Volcanic Field at SE Tibetan Plateau: Constraints on Petrogenesis and Mantle and Crustal Processes

Geological Journal, EarlyView.
Early zircon saturation and crystallisation occur in mafic (52–54 wt.% SiO2) lavas at Tengchong volcanic field. These early formed zircons with high δ18O (6.6‰–7.9‰) indicates mantle enrichment by subducted supracrustal materials. ABSTRACT Late Pleistocene (< 0.2 Ma) mafic and evolved volcanic rocks occur in northern Tengchong Volcanic Field, SE ...
Lizhu Wang, Haibo Zou
wiley   +1 more source

New Detections of Feldspar‐Bearing Volcanic Rocks in the Walls of Valles Marineris, Mars

Geophysical Research Letters, 2023
Plagioclase‐bearing rocks were first detected in the vicinity of large impact basins on Mars using visible/near‐infrared (VNIR) data. The geologic context is consistent with excavated plutons or ancient crustal outcrops.
Jessica Flahaut, Vincent Payet, Frank Fueten, Martin Guitreau, Marie Barthez, Gen Ito, Pascal Allemand   +6 more
doaj   +1 more source

A Reassessment of Petrochemistry of ~1.2 Ga Tonalitic Rocks of the Northern Tugela Terrane, Natal Metamorphic Belt, South Africa: Further Constraints on the Evolution of This Belt

Geological Journal, EarlyView.
Our petrochemical studies on ~1.2 Ga granitoids of the Natal Metamorphic Belt, South Africa, do not suggest any property similar to Phanerozoic‐style subduction‐related granitoids. Plot of Kotongweni Tonalite in Y versus Sr diagram (after Moyen 2011), note that most samples have Sr/Y < 50.
Palesa Leuta, Saumitra Misra, Thembiso O. Basupi   +2 more
wiley   +1 more source

Apatite in Carbonatite Preserving Primary Magmatic, Post‐Magmatic Overgrowth, and Post India‐Asia Collision‐Related Hydrothermal Alteration: Evidenced From U–Pb Isotope and Trace Element Geochemistry

Geological Journal, EarlyView.
U–Pb isotope and trace element geochemistry of apatite from carbonatites of Peshawar Plain Alkaline Igneous Province, western Himalaya shows Permo‐Carboniferous magmatism, an additional magmatic pulse during Cretaceous, and post‐magmatic hydrothermal/metasomatism during Oligocene. ABSTRACT U–Pb isotope and trace element geochemistry of apatite combined
Mehboob ur Rashid, Hafiz U. Rehman, Hao‐Yang Lee, Sun‐Lin Chung, Kaushik Das, Kazumasa Aoki, Muhammad Jawad Zeb, Nasir Ahmad, Muhammad Hussain, Hiroshi Yamamoto   +9 more
wiley   +1 more source

Heterogeneous Exhumation Mechanisms in Neoproterozoic Collisional Metamorphism: P–T Constraints From Pelotas and Punta del Este Terranes, Southern Brazil and Uruguay

Geological Journal, EarlyView.
Petrography, thermobarometry, and pseudosection modelling reveal peak metamorphic conditions of 3–7.5 kbar and 520°C–800°C in Tonian‐Cryogenian orthogneisses of the Dom Feliciano Belt. Metamorphic field gradients of 27°C/km–39°C/km and variable exhumation mechanisms support correlation of these units as remnants of a Himalayan‐type Piratini Orogeny ...
Thaiane Niederauer‐Santos, Carla Cristine Porcher, Daniel Triboli Vieira, Edinei Koester, Diego Jaldín, Karina Luengo, Luisa Caon   +6 more
wiley   +1 more source