Results 41 to 50 of about 1,569 (144)

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

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

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

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  

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

Petrogenesis and Tectonic Setting of Late Mesozoic Felsic Magmatic Rocks in the Wangmushan Mining District, Northern Fujian, South China

Geological Journal, EarlyView.
The rhyolitic ignimbrite and K‐feldspar granite porphyry from the Wangmushan mining district, northern Fujian yield ages of 173.8 ± 0.8 and 102.6 ± 0.4 Ma, respectively. Geochemical data, zircon trace elements, whole‐rock Sr–Nd–Pb isotope data, and zircon Hf isotopic compositions indicate that the rhyolitic ignimbrite originated from partial remelting ...
Wei Shaogang, Hong Wentao, Xiao Fan, Jin Guodong, Shi Hongyang, Ma Zhiwang, Wu Chen, Xue Yujingyang   +7 more
wiley   +1 more source

New Schmidt hammer exposure‐age dating calibrations for the Last Glacial Termination in NW Scotland: Development and application to undated Torridon Group sandstone surfaces in Wester Ross

Journal of Quaternary Science, EarlyView.
ABSTRACT An understanding of the terrestrial extent, retreat dynamics and climate–glacier coupling of ice masses during the Last Glacial Termination (LGT, ~18–11 ka) is often limited by a fragmentary geomorphological record and is dependent on precise, accurate and robust dating frameworks.
Alastair M. Curry, David Small, Oliver T. Bartlett, Jonathan Newitt   +3 more
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

Particle‐Scale Mechanics of a Regolith‐Type Soil

International Journal for Numerical and Analytical Methods in Geomechanics, EarlyView.
ABSTRACT The existing studies have reported that the surface of Mars shows the presence of materials having igneous origin, including basalt and regolith‐type coarse soils. These findings are affected by significant uncertainties and, therefore, the selection of simulants for various exploration applications, including surface mobility of rovers ...
Vincenzo Nardelli, Chencheng Wang, Matthew Richard Coop   +2 more
wiley   +1 more source

Soil wetting and drying processes influence stone artefact distribution in clay‐rich soils: A case study from Middle Gidley Island in Murujuga, northwest Western Australia

Archaeometry, EarlyView.
Abstract Soils that contain swelling clay minerals (e.g., montmorillonite) expand and contract during wetting and drying, causing movement within the soil profile. This process, known as argilliturbation, can alter artefact distributions, destroy stratigraphy and complicate the interpretation of archaeological deposits.
Caroline Mather, Matthias Leopold, Kaitlin Sullivan, Kane Ditchfield, Tom Horrocks, Luke Gliganic, Emma Beckett, Diana Patalwala, Emielda Yusiharni, Michael Smirk, William Hiscock, Jo McDonald   +11 more
wiley   +1 more source