scholarly journals Melt pockets in phenocrysts and decompression rates of silicic magmas before fragmentation

2007 ◽  
Vol 112 (B6) ◽  
Author(s):  
Yang Liu ◽  
Alfred T. Anderson ◽  
Colin J. N. Wilson
Keyword(s):  
Silicic Magmas ◽  
Melt Pockets

The imprint of basalt on the geochemistry of silicic magmas

1998 ◽  
Vol 160 (3-4) ◽  
pp. 433-445 ◽  
Author(s):  
Don Snyder ◽  
Stephen Tait
Keyword(s):  
Silicic Magmas

scholarly journals Origin and Evolution of Silicic Magmas in Oceanic Arcs; an in situ Study from St Lucia, Lesser Antilles

2017 ◽  
Vol 58 (7) ◽  
pp. 1279-1318 ◽  
Author(s):  
Rachel Bezard ◽  
Simon Turner ◽  
Jon Davidson ◽  
Axel K Schmitt ◽  
Jan Lindsay
Keyword(s):  
Lesser Antilles ◽  
Origin And Evolution ◽  
In Situ Study ◽  
Silicic Magmas

Genesis of silicic magmas during tertiary continental rifting in Yemen

Lithos ◽  
1995 ◽  
Vol 36 (2) ◽  
pp. 69-83 ◽  
Author(s):  
G. Chazot ◽  
H. Bertrand
Keyword(s):  
Continental Rifting ◽  
Silicic Magmas

Reactive bulk assimilation: A model for crust-mantle mixing in silicic magmas

Geology ◽  
2005 ◽  
Vol 33 (8) ◽  
pp. 681-684 ◽  
Author(s):  
James S. Beard ◽  
Paul C. Ragland ◽  
Maria Luisa Crawford
Keyword(s):  
Dehydration Melting ◽  
Crustal Rocks ◽  
Host Magma ◽  
Ti Oxides ◽  
Energy Penalty ◽  
Magma Crystallization ◽  
Hydrous Melt ◽  
Silicic Magmas ◽  
Solid Form ◽  
Hydrous Magma

Abstract Bulk assimilation of small (millimeters to ∼1 km) fragments of crust—driven and (ultimately) masked by reactions during xenolith melting and magma crystallization—is an important mechanism for crust-mantle mixing. Xenoliths containing mica or amphibole undergo dehydration melting when incorporated into a host magma, yielding mainly plagioclase, pyroxene, Fe-Ti oxides, and hydrous melt. The xenolith is physically compromised by partial melting and begins to disintegrate; xenolithic melt and crystals are mixed into the host magma. Xenocrystic zircon is liberated at this stage. The cryptic character of assimilation is greatly enhanced in any hydrous magma by hydration crystallization reactions (the reverse of dehydration melting). All pyroxenes and oxides (phenocrysts, xenocrysts, or crystals having a hybrid signature) will be subject to these reactions, producing feldspars, amphiboles, and micas that incorporate material from several sources, a particularly effective mixing mechanism. Implicit in the model is a reduced energy penalty for bulk assimilation—much of the assimilant remains in solid form—compared to melt-assimilation models. A large role for bulk assimilation supports stoping as a credible mechanism for the ascent of magmas. While the assimilation of low-density crust and concomitant fractionation provide the isostatic impetus for ascent, the wholesale incorporation and processing of crustal rocks in the magma chamber helps create the room for ascent.

scholarly journals Low-δ18O silicic magmas on Earth: A review

2020 ◽  
Vol 208 ◽  
pp. 103299
Author(s):  
Juliana Troch ◽  
Ben S. Ellis ◽  
Chris Harris ◽  
Olivier Bachmann ◽  
Ilya N. Bindeman
Keyword(s):  
Silicic Magmas

scholarly journals Advances in Cosmochemistry Enabled by Antarctic Meteorites

2020 ◽  
Vol 48 (1) ◽  
pp. 233-258
Author(s):  
Meenakshi Wadhwa ◽  
Timothy J. McCoy ◽  
Devin L. Schrader
Keyword(s):  
Solar System ◽  
Planetary Science ◽  
The Moon ◽  
Origin And Evolution ◽  
Lunar Meteorite ◽  
Planetary Bodies ◽  
The Antarctic ◽  
Melt Pockets ◽  
Scientific Advances

At present, meteorites collected in Antarctica dominate the total number of the world's known meteorites. We focus here on the scientific advances in cosmochemistry and planetary science that have been enabled by access to, and investigations of, these Antarctic meteorites. A meteorite recovered during one of the earliest field seasons of systematic searches, Elephant Moraine (EET) A79001, was identified as having originated on Mars based on the composition of gases released from shock melt pockets in this rock. Subsequently, the first lunar meteorite, Allan Hills (ALH) 81005, was also recovered from the Antarctic. Since then, many more meteorites belonging to these two classes of planetary meteorites, as well as other previously rare or unknown classes of meteorites (particularly primitive chondrites and achondrites), have been recovered from Antarctica. Studies of these samples are providing unique insights into the origin and evolution of the Solar System and planetary bodies. ▪  Antarctic meteorites dominate the inventory of the world's known meteorites and provide access to new types of planetary and asteroidal materials. ▪  The first meteorites recognized to be of lunar and martian origin were collected from Antarctica and provided unique constraints on the evolution of the Moon and Mars. ▪  Previously rare or unknown classes of meteorites have been recovered from Antarctica and provide new insights into the origin and evolution of the Solar System.

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