Results 41 to 50 of about 552,470 (226)

Melt channelization in ascending mantle [PDF]

Journal of Geophysical Research: Solid Earth, 2009
We study a model for channels of magma flow within mantle undergoing decompression melting. Cylindrical conduits in a viscous, porous, compacting matrix are considered, and it is found that the dynamics of the conduit walls are governed by the competition between melting (caused by decompression) and viscous closure (caused by the reduced pressure in ...
Hewitt, I, Fowler, A
openaire   +2 more sources

Fe–FeO and Fe–Fe 3 C melting relations at Earth's core–mantle boundary conditions: Implications for a volatile-rich or oxygen-rich core

, 2017
Eutectic melting temperatures in the Fe–FeO and Fe–Fe3C systems have been determined up to 150 GPa. Melting criteria include observation of a diffuse scattering signal by in situ X-Ray diffraction, and textural characterisation of recovered samples.
G. Morard, D. Andrault, D. Antonangeli, Y. Nakajima, A. Auzende, E. Boulard, S. Cervera, A. Clark, Oliver Thomas Lord, J. Siebert, V. Svitlyk, G. Garbarino, M. Mezouar   +12 more
semanticscholar   +1 more source

Contrasting partition behavior of F and Cl during hydrous mantle melting: implications for Cl/F signature in arc magmas

Progress in Earth and Planetary Science, 2014
We present the results of five experiments on F and Cl partitioning during hydrous mantle melting under conditions relevant to subduction zone magmatism (1.2–2.5 GPa, 1,180°C–1,430°C).
C. Dalou, K. Koga, M. Le Voyer, N. Shimizu   +3 more
semanticscholar   +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

Rapid transition from primary to secondary crust building on the Moon explained by mantle overturn

Nature Communications, 2023
Geochronology indicates a rapid transition (tens of Myrs) from primary to secondary crust building on the Moon. The processes responsible for initiating secondary magmatism, however, remain in debate.
Tabb C. Prissel, Nan Zhang, Colin R. M. Jackson, Haoyuan Li   +3 more
doaj   +1 more source

Experimental evidence supports mantle partial melting in the asthenosphere

Science Advances, 2016
Based on sound velocity measurements, upper mantle seismic anomalies could be explained by a melt fraction as low as 0.2%. The low-velocity zone (LVZ) is a persistent seismic feature in a broad range of geological contexts. It coincides in depth with the
J. Chantel, G. Manthilake, D. Andrault, D. Novella, Tony Yu, Yanbin Wang   +5 more
semanticscholar   +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

The Meaning of Pressure for Primary Magmas: New Insights From PRIMELT3‐P

Geochemistry, Geophysics, Geosystems, 2023
This paper reports new software, PRIMELT3‐P, for computing the pressure and temperature range over which a primary basaltic magma was formed by adiabatic decompression and fractional melting of fertile mantle peridotite.
Claude T. Herzberg, Paul D. Asimow, Juan David Hernández‐Montenegro   +2 more
doaj   +1 more source

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

Europium in plagioclase-hosted melt inclusions reveals mantle melting modulates oxygen fugacity

Nature Communications
To gain insights into the composition and heterogeneity of Earth’s interior, the partial pressure of oxygen (oxygen fugacity, or fO2) in igneous rocks is characterized. A surprising observation is that relative to reference buffers, fO2s of mantle melts (
Nicholas Dygert, Gokce K. Ustunisik, Roger L. Nielsen   +2 more
doaj   +1 more source