The highly siderophile elements and Re-Os isotope geochemistry
of Variscan lamproites from the Bohemian Massif: implications
for regionally dependent metasomatism of orogenic mantle

J 2020

The highly siderophile elements and Re-Os isotope geochemistry of Variscan lamproites from the Bohemian Massif: implications for regionally dependent metasomatism of orogenic mantle

KRMÍČEK, Lukáš; Lukáš ACKERMAN; Jakub HRUBÝ a Jindřich KYNICKÝ

Základní údaje

Originální název

The highly siderophile elements and Re-Os isotope geochemistry of Variscan lamproites from the Bohemian Massif: implications for regionally dependent metasomatism of orogenic mantle

Autoři

KRMÍČEK, Lukáš; Lukáš ACKERMAN; Jakub HRUBÝ a Jindřich KYNICKÝ

Vydání

Chemical Geology, Amsterdam, Elsevier, 2020, 0009-2541

Další údaje

Jazyk

angličtina

Typ výsledku

Článek v odborném periodiku

Obor

10505 Geology

Stát vydavatele

Nizozemské království

Utajení

není předmětem státního či obchodního tajemství

Odkazy

URL

Impakt faktor

Impact factor: 4.015

Kód RIV

RIV/00216224:14310/20:00117049

Organizační jednotka

Přírodovědecká fakulta

DOI

https://doi.org/10.1016/j.chemgeo.2019.119290

UT WoS

000513868400032

EID Scopus

2-s2.0-85075060187

Klíčová slova anglicky

Orogenic mantle; HSE; Re-Os; Lamproites; Saxo-Thuringian Zone; Moldanubian Zone

Štítky

14315010, rivok

Příznaky

Mezinárodní význam, Recenzováno

Změněno: 23. 11. 2020 13:35, Mgr. Marie Novosadová Šípková, DiS.

Anotace

V originále

Orogenic lamproites represent a group of peralkaline, ultrapotassic and perpotassic mantle-derived igneous rocks that hold the potential to sample components with extreme compositions from highly heterogeneous orogenic mantle. In our pilot study, we present highly siderophile element (HSE) and Re-Os isotope systematics of Variscan orogenic lamproites sampled in the territories of the Czech Republic, Austria and Poland, i.e., from the termination of the Moldanubian and Saxo-Thuringian zones of the Bohemian Massif. Orogenic lamproites of the Bohemian Massif are distinguished by variably high contents of SiO2 , high Mg# and predominant mineral associations of K-rich amphibole and Fe-rich microcline. The HSE show (i) consistently very low contents in all investigated orogenic lamproites compared to the estimated concentrations in majority of mid-ocean ridge basalts, hotspot-related volcanic rocks (e.g., ocean island basalts, continental flood basalts, komatiites, some intraplate alkaline volcanic rocks such as kimberlites and anorogenic lamproites) and arc lavas, and (ii) marked differences in relative and absolute HSE abundances between the samples from the Moldanubian and Saxo-Thuringian Zone. Such a regional dependence in HSE from mantle-derived melts is exceptional. Orogenic lamproites have highly variable and high initial suprachondritic Os-187/Os-188 values (up to 0.631) compared with rather chondritic to subchondritic Os isotope values of the young lithospheric mantle below the Bohemian Massif. The highly radiogenic Os isotope component in orogenic lamproites may be derived from preferential melting of metasomatised vein assemblages sitting in depleted peridotite mantle. This process appears to be valid generally in the petrogenesis of orogenic lamproites both from the Bohemian Massif and from the Mediterranean area. As a specific feature of the orogenic lamproites from the Bohemian Massif, originally ultra-depleted mantle component correlative with remnants of the Rheic Ocean lithosphere in the Moldanubian Zone was metasomatised by a mixture of evolved and juvenile material, whereas the lithospheric mantle in the Saxo-Thuringian Zone was enriched through the subduction of evolved crustal material with highly radiogenic Sr isotope signature. As a result, this led to observed unique regionally dependent coupled HSE, Rb-Sr and Re-Os isotope systematics.

Citovat

KRMÍČEK, Lukáš; Lukáš ACKERMAN; Jakub HRUBÝ a Jindřich KYNICKÝ. The highly siderophile elements and Re-Os isotope geochemistry of Variscan lamproites from the Bohemian Massif: implications for regionally dependent metasomatism of orogenic mantle. Chemical Geology. Amsterdam: Elsevier, 2020, roč. 532, JAN 20 2020, s. 1-11. ISSN 0009-2541. Dostupné z: https://doi.org/10.1016/j.chemgeo.2019.119290.

@article{1698338,
   author = {Krmíček, Lukáš and Ackerman, Lukáš and Hrubý, Jakub and Kynický, Jindřich},
   article_location = {Amsterdam},
   article_number = {JAN 20 2020},
   doi = {https://doi.org/10.1016/j.chemgeo.2019.119290},
   keywords = {Orogenic mantle; HSE; Re-Os; Lamproites; Saxo-Thuringian Zone; Moldanubian Zone},
   language = {eng},
   issn = {0009-2541},
   journal = {Chemical Geology},
   title = {The highly siderophile elements and Re-Os isotope geochemistry of Variscan lamproites from the Bohemian Massif: implications for regionally dependent metasomatism of orogenic mantle},
   url = {https://doi.org/10.1016/j.chemgeo.2019.119290},
   volume = {532},
   year = {2020}
}

TY  - JOUR
ID  - 1698338
AU  - Krmíček, Lukáš - Ackerman, Lukáš - Hrubý, Jakub - Kynický, Jindřich
PY  - 2020
TI  - The highly siderophile elements and Re-Os isotope geochemistry of Variscan lamproites from the Bohemian Massif: implications for regionally dependent metasomatism of orogenic mantle
JF  - Chemical Geology
VL  - 532
IS  - JAN 20 2020
SP  - 1-11
EP  - 1-11
PB  - Elsevier
SN  - 00092541
KW  - Orogenic mantle
KW  - HSE
KW  - Re-Os
KW  - Lamproites
KW  - Saxo-Thuringian Zone
KW  - Moldanubian Zone
UR  - https://doi.org/10.1016/j.chemgeo.2019.119290
L2  - https://doi.org/10.1016/j.chemgeo.2019.119290
N2  - Orogenic lamproites represent a group of peralkaline, ultrapotassic and perpotassic mantle-derived igneous rocks that hold the potential to sample components with extreme compositions from highly heterogeneous orogenic mantle. In our pilot study, we present highly siderophile element (HSE) and Re-Os isotope systematics of Variscan orogenic lamproites sampled in the territories of the Czech Republic, Austria and Poland, i.e., from the termination of the Moldanubian and Saxo-Thuringian zones of the Bohemian Massif. Orogenic lamproites of the Bohemian Massif are distinguished by variably high contents of SiO2 , high Mg# and predominant mineral associations of K-rich amphibole and Fe-rich microcline. The HSE show (i) consistently very low contents in all investigated orogenic lamproites compared to the estimated concentrations in majority of mid-ocean ridge basalts, hotspot-related volcanic rocks (e.g., ocean island basalts, continental flood basalts, komatiites, some intraplate alkaline volcanic rocks such as kimberlites and anorogenic lamproites) and arc lavas, and (ii) marked differences in relative and absolute HSE abundances between the samples from the Moldanubian and Saxo-Thuringian Zone. Such a regional dependence in HSE from mantle-derived melts is exceptional. Orogenic lamproites have highly variable and high initial suprachondritic Os-187/Os-188 values (up to 0.631) compared with rather chondritic to subchondritic Os isotope values of the young lithospheric mantle below the Bohemian Massif. The highly radiogenic Os isotope component in orogenic lamproites may be derived from preferential melting of metasomatised vein assemblages sitting in depleted peridotite mantle. This process appears to be valid generally in the petrogenesis of orogenic lamproites both from the Bohemian Massif and from the Mediterranean area. As a specific feature of the orogenic lamproites from the Bohemian Massif, originally ultra-depleted mantle component correlative with remnants of the Rheic Ocean lithosphere in the Moldanubian Zone was metasomatised by a mixture of evolved and juvenile material, whereas the lithospheric mantle in the Saxo-Thuringian Zone was enriched through the subduction of evolved crustal material with highly radiogenic Sr isotope signature. As a result, this led to observed unique regionally dependent coupled HSE, Rb-Sr and Re-Os isotope systematics.
ER  -

KRMÍČEK, Lukáš; Lukáš ACKERMAN; Jakub HRUBÝ a Jindřich KYNICKÝ. The highly siderophile elements and Re-Os isotope geochemistry of Variscan lamproites from the Bohemian Massif: implications for regionally dependent metasomatism of orogenic mantle. \textit{Chemical Geology}. Amsterdam: Elsevier, 2020, roč.~532, JAN 20 2020, s.~1-11. ISSN~0009-2541. Dostupné z: https://doi.org/10.1016/j.chemgeo.2019.119290.

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