2016
Rhenium–osmium isotopes in pervasively metasomatized mantle xenoliths from the Bohemian Massif and implications for the reliability of Os model ages.
KOCHERGINA, Yulia V., Lukáš ACKERMAN, Vojtěch ERBAN, Magda MATUSIAK-MAŁEK, Jacek PUZIEWICZ et. al.Základní údaje
Originální název
Rhenium–osmium isotopes in pervasively metasomatized mantle xenoliths from the Bohemian Massif and implications for the reliability of Os model ages.
Autoři
KOCHERGINA, Yulia V. (203 Česká republika), Lukáš ACKERMAN (203 Česká republika), Vojtěch ERBAN (203 Česká republika), Magda MATUSIAK-MAŁEK (616 Polsko), Jacek PUZIEWICZ (616 Polsko), Patricie HALODOVÁ (203 Česká republika), Petr ŠPAČEK (203 Česká republika, domácí), Jakub TRUBAČ (203 Česká republika) a Tomáš MAGNA (203 Česká republika)
Vydání
Chemical Geology, Amsterdam, Elsevier, 2016, 0009-2541
Další údaje
Jazyk
angličtina
Typ výsledku
Článek v odborném periodiku
Obor
Geochemie
Stát vydavatele
Nizozemské království
Utajení
není předmětem státního či obchodního tajemství
Impakt faktor
Impact factor: 3.347
Kód RIV
RIV/00216224:14310/16:00088679
Organizační jednotka
Přírodovědecká fakulta
UT WoS
000374658500008
Klíčová slova anglicky
Sub-continental lithospheric mantle; Peridotite xenolith; Bohemian Massif; Ohře/Eger rift; Os isotopes; Re–Os; Depletion age
Změněno: 13. 4. 2017 21:09, Ing. Andrea Mikešková
Anotace
V originále
Peridotite xenoliths brought to the surface by basaltic lavas attest to a variety of mantle processes, including partial melting, melt percolation or refertilization. The whole rock Re–Os concentrations and Os isotopic compositions were determined for 30 xenoliths collected from 11 localities across the northern Bohemian Massif in order to evaluate the Os model ages and attempt to relate the results to major crustal tectonic events during the history. Most samples were affected by variable extent of metasomatic overprint, which is commonly paralleled by very low Os concentrations (<1 ppb). Rhenium concentrations in the whole suite are below the primitive mantle value. A subset of samples shows evidence for Re addition from host basaltic rocks, consistent with the presence of abundant melt pockets with secondary sulphides. The 187Os/188Os ratios range from 0.1162 to 0.1330 and cannot be directly related to individual mantle domains, implying the inability of more recent tectonic events to reset the original Os isotopic systematics. The calculated mantle extraction ages (TMA) range from <0.1 to 2.1 Ga, whereas future ages obtained for nine samples indicate metasomatic overprints. The Re depletion ages (TRD) varybetween <0.1 and ~1.6 Ga. However, the TRD is not well suited for direct comparisonwith crustal ages because it represents a minimum age limit rather than specific age estimate. Therefore, a modified model age (TRDII) was calculated assuming a non-zero Re content during the pre-metasomatic stage and using a composition of the most depleted sample in our suite. A prominent peak in the calculated TRDII ages ranges between 0.5 and 0.6 Ga which corresponds to the Cadomian orogenic cycle.
Návaznosti
GAP210/12/0573, projekt VaV |
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