Identifying crustal contributions in the Patagonian Chon Aike Silicic Large Igneous Province

Details

Serval ID
serval:BIB_D4B504BA1BAB
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Identifying crustal contributions in the Patagonian Chon Aike Silicic Large Igneous Province
Journal
Contributions to Mineralogy and Petrology
Author(s)
Foley Michelle L., Putlitz Benita, Baumgartner Lukas P., Renda Emiliano M., Ulianov Alexey, Siron Guillaume, Chiaradia Massimo
ISSN
0010-7999
1432-0967
Publication state
Published
Issued date
11/2023
Volume
178
Number
11
Language
english
Abstract
<jats:title>Abstract</jats:title><jats:p>The volcanic rocks of the Chon Aike Silicic Large Igneous Province (CASP) are recognized as magmas dominantly produced by crustal anatexis. Investigating the zircon of the CASP provides an opportunity to gain further insight into geochemical and isotopic differences of the potential magmatic sources (i.e., crust versus mantle), to identify crustal reservoirs that contributed to the felsic magmas during anatexis, and to quantify the contributions of the respective sources. We present a combined zircon oxygen and hafnium isotope and trace element dataset for 16 volcanic units of the two youngest volcanic phases in Patagonia, dated here with LA-ICP-MS U–Pb geochronology at ca. 148–153 Ma (El Quemado Complex, EQC) and ca. 159 Ma (western Chon Aike Formation, WCA). The EQC zircon have <jats:sup>18</jats:sup>O-enriched values (δ<jats:sup>18</jats:sup>O from 7 to 9.5‰) with correspondingly negative initial εHf values (− 2.0 to − 8.0). The WCA zircon have δ<jats:sup>18</jats:sup>O values between 6 and 7‰ and εHf values ranging between − 4.0 and + 1.5. Binary δ<jats:sup>18</jats:sup>O-εHf mixing models require an average of 70 and 60% melt derived from partial melting of isotopically distinct metasedimentary basements for the EQC and WCA, respectively. Zircon trace element compositions are consistent with anatexis of sedimentary protoliths derived from LIL-depleted upper continental crustal sources. The overlap between a high heat flux environment (i.e., widespread extension and lithospheric thinning) during supercontinental breakup and a fertile metasedimentary crust was key in producing voluminous felsic volcanism via anatexis following the injection and emplacement of basaltic magmas into the lower crust.</jats:p>
Pubmed
Web of science
Open Access
Yes
Funding(s)
Swiss National Science Foundation / 200021_175808
University of Lausanne
Create date
13/11/2024 17:30
Last modification date
03/12/2024 7:08
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