Mechanical anisotropies and mechanisms of mafic magma ascent in the middle continental crust: The Sondalo magmatic system (N Italy)
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00025798%3A_____%2F18%3A00000190" target="_blank" >RIV/00025798:_____/18:00000190 - isvavai.cz</a>
Result on the web
<a href="https://pubs.geoscienceworld.org/gsabulletin/article-lookup?doi=10.1130/B31693.1" target="_blank" >https://pubs.geoscienceworld.org/gsabulletin/article-lookup?doi=10.1130/B31693.1</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1130/B31693.1" target="_blank" >10.1130/B31693.1</a>
Alternative languages
Result language
angličtina
Original language name
Mechanical anisotropies and mechanisms of mafic magma ascent in the middle continental crust: The Sondalo magmatic system (N Italy)
Original language description
Magma transfer between lower and upper continental crust is a fundamental process linking the dominantly mafic composition of the lower crust with the more felsic composition of the upper crust. We explored the mechanisms of mafic magma ascent and emplacement in the middle crust by studying a midcrustal gabbroic to dioritic magmatic system (Sondalo complex, eastern central Alps, northern Italy). We characterized the structure and anisotropy of magnetic susceptibility (AMS) fabric of concentric gabbroic to dioritic intrusions. The significance of AMS fabrics is discussed using anisotropy of anhysteretic remanent magnetization (AARM) and crystallographic preferred orientation (CPO) data acquired on different test sites. The magmatic and magnetic fabrics of the pluton were acquired during its emplacement in the Permian and were not subsequently tilted: The fabrics are essentially vertical, indicating vertical magma transfer through the crust with a two-phase intrusion history. (1) The concordant orientation between the magmatic foliation and the host-rock xenoliths in the center of the pluton suggests that the first magma ascent phase occurred along pathways subparallel to the vertical fabric of the host metasedi- mentary rocks. (2) The second magma ascent phase was controlled by a change in the rheology of the host rock and the mafic magma. Heat dissipation to the contact aureole induced partial melting, thereby lowering the mechanical strength of the host rocks, whereas the viscosity of the mafic magma increased due to cooling and associated fractional crystallization. This caused an en-masse rise of the pluton, resulting in the formation of a structural aureole, i.e., a vertical foliation in the contact aureole and a weaker but concordant magmatic foliation at the rim of the pluton. This ascent phase accounts for the pressure-temperature evolution recorded by metasedimentary rocks in the contact aureole of the pluton.
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10505 - Geology
Result continuities
Project
<a href="/en/project/GA16-17457S" target="_blank" >GA16-17457S: Melting the metagranitoids: important but poorly understood aspect of crust evolution</a><br>
Continuities
P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)
Others
Publication year
2018
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Geological Society of America Bulletin
ISSN
0016-7606
e-ISSN
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Volume of the periodical
130
Issue of the periodical within the volume
1-2
Country of publishing house
US - UNITED STATES
Number of pages
22
Pages from-to
331-352
UT code for WoS article
000418364200017
EID of the result in the Scopus database
2-s2.0-85038841115