Role of the overriding plate in arc magma evolution

2006 ◽  
Vol 70 (18) ◽  
pp. A21
Author(s):  
R.J. Arculus
Keyword(s):  
Geology ◽  
2020 ◽  
Vol 48 (4) ◽  
pp. 323-327 ◽  
Author(s):  
Chetan L. Nathwani ◽  
Matthew A. Loader ◽  
Jamie J. Wilkinson ◽  
Yannick Buret ◽  
Robert H. Sievwright ◽  
...  

Abstract Protracted magma storage in the deep crust is a key stage in the formation of evolved, hydrous arc magmas that can result in explosive volcanism and the formation of economically valuable magmatic-hydrothermal ore deposits. High magmatic water content in the deep crust results in extensive amphibole ± garnet fractionation and the suppression of plagioclase crystallization as recorded by elevated Sr/Y ratios and high Eu (high Eu/Eu*) in the melt. Here, we use a novel approach to track the petrogenesis of arc magmas using apatite trace element chemistry in volcanic formations from the Cenozoic arc of central Chile. These rocks formed in a magmatic cycle that culminated in high-Sr/Y magmatism and porphyry ore deposit formation in the Miocene. We use Sr/Y, Eu/Eu*, and Mg in apatite to track discrete stages of arc magma evolution. We apply fractional crystallization modeling to show that early-crystallizing apatite can inherit a high-Sr/Y and high-Eu/Eu* melt chemistry signature that is predetermined by amphibole-dominated fractional crystallization in the lower crust. Our modeling shows that crystallization of the in situ host-rock mineral assemblage in the shallow crust causes competition for trace elements in the melt that leads to apatite compositions diverging from bulk-magma chemistry. Understanding this decoupling behavior is important for the use of apatite as an indicator of metallogenic fertility in arcs and for interpretation of provenance in detrital studies.


Island Arc ◽  
2010 ◽  
Vol 19 (1) ◽  
pp. 4-16 ◽  
Author(s):  
Dapeng Zhao ◽  
M. Santosh ◽  
Akira Yamada
Keyword(s):  

2007 ◽  
Vol 48 (10) ◽  
pp. 1999-2031 ◽  
Author(s):  
Y. Tamura ◽  
K. Tani ◽  
Q. Chang ◽  
H. Shukuno ◽  
H. Kawabata ◽  
...  
Keyword(s):  

2018 ◽  
Vol 47 (2) ◽  
pp. 25-46
Author(s):  
Irena Peytcheva ◽  
Elena Tacheva ◽  
Albrecht von Quadt ◽  
Rossen Nedialkov

A combination of methods is applied in the present study to define the exact age of the Petrohan and Mezdreya plutons and trace their magma evolution. Field, petrological, and geochemical studies of the Petrohan pluton revealed its complex evolution and emphasized the role of magma mingling and mixing, complementary to the normal assimilation and fractional crystallization (AFC) processes. Using high-precision conventional U-Pb (CA)-ID-TIMS zircon and titanite dating in combination with CA-LA-ICP-MS zircon dating and tracing, we suggest an incremental growth of a common Petrohan-Mezdreya pluton. It was assembled over minimum 4.5 Ma from 311.14±0.48 Ma to 307.54±0.54 Ma. The younger age of the gabbro (308.12±0.33 Ma), compared with the age of granodiorites (311.14±0.48 Ma), provides numerical proofs for magma replenishment during the assembling of the Petrohan pluton. Whole-rock strontium-neodymium (initial 87Sr/86Sr ratios of 0.70521–0.70527 to 0.70462 and 143Nd/144Nd of 0.51221 to 0.51210) and Hf-zircon isotope data (ε-Hf from –5.8 to +3.6) argue for interaction of mantle derived magma with crustal melts but also mixing and mingling and transfer of zircon grains between the gabbroic and granitic melts. Possible petrogenetic scenario includes melting of subcontinental mantle lithosphere and crust and evolution trough AFC, FC and mingling/mixing processes. Considering the Petrohan-Mezdreya pluton as part of the Variscan orogeny in SE Europe, our new data support the accretion/collision of both the Balkan and Sredna Gora/Getic units with Moesia in the Early Carboniferous followed by syn- and post-collisional Carboniferous and Permian magmatism.


2013 ◽  
Vol 263 ◽  
pp. 224-237 ◽  
Author(s):  
Georges Boudon ◽  
Benoît Villemant ◽  
Anne Le Friant ◽  
Martine Paterne ◽  
Elsa Cortijo

2018 ◽  
Vol 103 (6) ◽  
pp. 899-910 ◽  
Author(s):  
Vanni Tecchiato ◽  
Mario Gaeta ◽  
Silvio Mollo ◽  
Olivier Bachmann ◽  
Albrecht von Quadt ◽  
...  

Nature ◽  
1991 ◽  
Vol 349 (6304) ◽  
pp. 56-58 ◽  
Author(s):  
Bruce C. Jago ◽  
John Gittins

Sign in / Sign up

Export Citation Format

Share Document