TY - JOUR

T1 - Iron isotope and trace metal variations during mantle metasomatism

T2 - In situ study on sulfide minerals from peridotite xenoliths from Nógrád-Gömör Volcanic Field (Northern Pannonian Basin)

AU - Patkó, Levente

AU - Ciazela, Jakub

AU - Aradi, László Előd

AU - Liptai, Nóra

AU - Pieterek, Bartosz

AU - Berkesi, Márta

AU - Lazarov, Marina

AU - Kovács, István János

AU - Holtz, François

AU - Szabó, Csaba

N1 - Funding Information: This research was funded by the National Science Centre Poland (PRELUDIUM 12 no. 2016/23/N/ST10/00288) to J. Ciążela, the MTA EK Lendület Pannon LitH 2 Oscope Grant (LP2018-5/2018) to I.J. Kovács, and the Hungarian Science Foundation (OTKA, 78425) to Cs. Szabó. L. Patkó was supported by the GINOP-2.3.2-15-2016-00009 research program. The work of L. Patkó, L.E. Aradi, and Cs. Szabó was funded by the Eötvös Loránd University (ELTE) Institutional Excellence Program (TKP2020-IKA-05) supported by the Hungarian Ministry of Human Capacities . This is the 105 th publication of the Lithosphere Fluid Research Lab (LRG). Funding Information: The authors would like to thank to the people who supported this study. Zsolt Bend?, Zolt?n Kov?cs and ?bel Szab? are thanked for helping with the SEM analyses at the E?tv?s Lor?nd University. We are grateful to Bernardo Cesare, Anna Maria Fioretti and Ra?l Carampin for their help with the EMPA analyses at CNR Institute for Geosciences and Earth Resources (IGG) in Padua, Italy. Last but not least, we acknowledge Ingo Horn's help to set up the fs-LA-ICP-MS measurements at the Leibniz Universit?t Hannover. Xianhua Li is thanked for his editorial handling and useful suggestions, Sonja Aulbach and an anonym reviewer are thanked for their constructive comments and thorough structural shaping of the paper. This research was funded by the National Science Centre Poland (PRELUDIUM 12 no. 2016/23/N/ST10/00288) to J. Ci??ela, the MTA EK Lend?let Pannon LitH2Oscope Grant (LP2018-5/2018) to I.J. Kov?cs, and the Hungarian Science Foundation (OTKA, 78425) to Cs. Szab?. L. Patk? was supported by the GINOP-2.3.2-15-2016-00009 research program. The work of L. Patk?, L.E. Aradi, and Cs. Szab? was funded by the E?tv?s Lor?nd University (ELTE) Institutional Excellence Program (TKP2020-IKA-05) supported by the Hungarian Ministry of Human Capacities. This is the 105th publication of the Lithosphere Fluid Research Lab (LRG).

PY - 2021/9

Y1 - 2021/9

N2 - Sulfides from lherzolite and wehrlite xenoliths from the Nógrád-Gömör Volcanic Field (NGVF), located in the Northern Pannonian Basin, were studied to understand the behavior of chalcophile and siderophile elements during mafic melt – peridotite interaction. We applied in situ methods to analyze the major and trace elements, as well as Fe isotope compositions of sulfide minerals. Sulfides are more abundant in wehrlites (~0.03 vol%) and are often enclosed in silicates, whereas in lherzolites, they are scarcer (~0.01 vol%) and predominantly interstitial. Monosulfide solid solution and pentlandite are the most common sulfide phases in the lherzolite xenoliths, whereas in wehrlite xenoliths it is pyrrhotite and chalcopyrite. Consequently, wehrlitic sulfides show higher bulk Fe and Cu but lower bulk Ni and Co contents compared to the lherzolitic sulfides. Trace elements with both chalcophile and siderophile character (Ge, Se, Te, and Re) show lower, whereas highly chalcophile elements (Zn, Cd, Sb, and Tl) show higher concentrations in wehrlitic sulfides compared to lherzolitic ones. Highly siderophile elements show no systematic difference between the sulfides of the two xenolith series, which suggests moderate enrichment in these elements in wehrlite bulk rocks due to their higher sulfide content. Sulfide δ56Fe signature indicates variable isotopic composition both in lherzolites (δ56Fe: −0.13 to +0.56‰) and wehrlites (δ56Fe: −0.20 to +0.84‰) relative to the terrestrial mantle (δ56Fe: +0.025 ± 0.025‰; Craddock et al., 2013). However, irrespectively of the xenolith lithology, there is a significant difference between the δ56Fe of sulfides from the two sampling localities: NTB /North/: vary from −0.20 to +0.04‰ and NME /South/: vary from +0.56 to +0.84‰. This suggests that the Fe isotopic ratios of sulfides are not modified by the wehrlitization process. Difference in sulfide δ56Fe between the two xenolith localities is probably because of the higher, isotopically heavier (δ56Fe: from +1.28 to +1.60‰; Ciążela et al., 2019) chalcopyrite content in sulfides from the NME xenoliths compared to those from the NTB xenoliths irrespectively to their lithology. Our results also indicate sulfide and chalcophile element enrichment resulting from metasomatism in the subcontinental lithospheric mantle. We suggest that this process affected the regional metal distribution and has implications for global metal mass balance within the subcontinental lithosphere.

AB - Sulfides from lherzolite and wehrlite xenoliths from the Nógrád-Gömör Volcanic Field (NGVF), located in the Northern Pannonian Basin, were studied to understand the behavior of chalcophile and siderophile elements during mafic melt – peridotite interaction. We applied in situ methods to analyze the major and trace elements, as well as Fe isotope compositions of sulfide minerals. Sulfides are more abundant in wehrlites (~0.03 vol%) and are often enclosed in silicates, whereas in lherzolites, they are scarcer (~0.01 vol%) and predominantly interstitial. Monosulfide solid solution and pentlandite are the most common sulfide phases in the lherzolite xenoliths, whereas in wehrlite xenoliths it is pyrrhotite and chalcopyrite. Consequently, wehrlitic sulfides show higher bulk Fe and Cu but lower bulk Ni and Co contents compared to the lherzolitic sulfides. Trace elements with both chalcophile and siderophile character (Ge, Se, Te, and Re) show lower, whereas highly chalcophile elements (Zn, Cd, Sb, and Tl) show higher concentrations in wehrlitic sulfides compared to lherzolitic ones. Highly siderophile elements show no systematic difference between the sulfides of the two xenolith series, which suggests moderate enrichment in these elements in wehrlite bulk rocks due to their higher sulfide content. Sulfide δ56Fe signature indicates variable isotopic composition both in lherzolites (δ56Fe: −0.13 to +0.56‰) and wehrlites (δ56Fe: −0.20 to +0.84‰) relative to the terrestrial mantle (δ56Fe: +0.025 ± 0.025‰; Craddock et al., 2013). However, irrespectively of the xenolith lithology, there is a significant difference between the δ56Fe of sulfides from the two sampling localities: NTB /North/: vary from −0.20 to +0.04‰ and NME /South/: vary from +0.56 to +0.84‰. This suggests that the Fe isotopic ratios of sulfides are not modified by the wehrlitization process. Difference in sulfide δ56Fe between the two xenolith localities is probably because of the higher, isotopically heavier (δ56Fe: from +1.28 to +1.60‰; Ciążela et al., 2019) chalcopyrite content in sulfides from the NME xenoliths compared to those from the NTB xenoliths irrespectively to their lithology. Our results also indicate sulfide and chalcophile element enrichment resulting from metasomatism in the subcontinental lithospheric mantle. We suggest that this process affected the regional metal distribution and has implications for global metal mass balance within the subcontinental lithosphere.

KW - Fe isotope

KW - Mantle xenoliths

KW - Sulfide and chalcophile element enrichment

KW - Wehrlitic metasomatism

UR - http://www.scopus.com/inward/record.url?scp=85107137530&partnerID=8YFLogxK

U2 - 10.1016/j.lithos.2021.106238

DO - 10.1016/j.lithos.2021.106238

M3 - Article

AN - SCOPUS:85107137530

VL - 396-397

JO - LITHOS

JF - LITHOS

SN - 0024-4937

M1 - 106238

ER -