Number of the records: 1
Mantle Zn Isotopic Heterogeneity Caused by Melt‐Rock Reaction: Evidence From Fe‐Rich Peridotites and Pyroxenites From the Bohemian Massif, Central Europe
- 1.
SYSNO ASEP 0505049 Document Type J - Journal Article R&D Document Type Journal Article Subsidiary J Článek ve WOS Title Mantle Zn Isotopic Heterogeneity Caused by Melt‐Rock Reaction: Evidence From Fe‐Rich Peridotites and Pyroxenites From the Bohemian Massif, Central Europe Author(s) Huang, J. (CN)
Ackerman, Lukáš (GLU-S) RID, SAI, ORCID
Zhang, X-CH. (CN)Source Title Journal of Geophysical Research-Solid Earth. - : Wiley - ISSN 2169-9313
Roč. 124, č. 4 (2019), s. 3588-3604Number of pages 17 s. Publication form Print - P Language eng - English Country US - United States Keywords zinc isotopes ; peridotite ; pyroxenite ; melt‐rock reaction ; mantle heterogeneity Subject RIV DB - Geology ; Mineralogy OECD category Geology Method of publishing Limited access Institutional support GLU-S - RVO:67985831 UT WOS 000468912000020 EID SCOPUS 85065211757 DOI 10.1029/2018JB017125 Annotation To investigate the effect of melt‐rock reaction on Zn isotope fractionation and mantle Zn isotopic heterogeneity, we analyzed Zn isotopic compositions of peridotites, pyroxenites, and mineral separates from the Bohemian Massif, Central Europe. The Mg‐lherzolites (Mg# = 90.9 to 89.1, FeOT = 7.9 to 9.0 wt %) are melting residues with only moderate metasomatism and have δ66Zn from 0.11 to 0.20‰. In contrast, the Fe‐rich peridotites (Mg# = 88.2 to 80.3, FeOT = 10.0 to 14.5 wt %) and pyroxenites have larger ranges of δ66Zn from 0.11 to 0.31‰ and −0.33 to 0.42‰, respectively. Large disequilibrium intermineral Zn isotope fractionation occurs in the Fe‐rich peridotites and pyroxenites with Δ66ZnOpx‐Ol = −0.50‰, Δ66ZnGrt‐Ol = −0.55 to −0.39‰, Δ66ZnGrt‐Opx = −0.28 to −0.05‰, and Δ66ZnGrt‐Cpx = −0.50 to 0.12‰. Combined with their low SiO2 contents and radiogenic Sr‐Nd‐Os isotopic compositions, the high δ66Zn of the Fe‐rich peridotites is attributed to reaction between Mg‐lherzolites and percolating SiO2‐undersaturated basaltic melts that incorporated isotopically heavy crustal components. Crystallization of the isotopically heavy percolating melts migrating through the lithospheric mantle yield the high‐δ66Zn pyroxenites. The low δ66Zn of the pyroxenites and large intermineral Zn isotopic disequilibrium may result from kinetic Zn isotope fractionation during melt‐rock reaction. Collectively, these observations indicate that melt‐rock reaction can cause intermineral Zn isotopic disequilibrium and significant Zn isotopic heterogeneity in the mantle. This study thus highlights the potential use of Zn isotopes to trace melt‐rock reaction events in the mantle. Workplace Institute of Geology Contact Jana Popelková, popelkova@gli.cas.cz, Sabina Janíčková, Tel.: 233 087 272 Year of Publishing 2020 Electronic address https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2018JB017125
Number of the records: 1