Re-Os isotopic constraints on the source of platinum-group minerals (PGM) from the Vestřev pyrope-rich garnet placer deposit, Bohemian Massif

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00025798%3A_____%2F15%3A00000395" target="_blank" >RIV/00025798:_____/15:00000395 - isvavai.cz</a>

Výsledek na webu

<a href="https://www.sciencedirect.com/science/article/pii/S0169136815000268" target="_blank" >https://www.sciencedirect.com/science/article/pii/S0169136815000268</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.oregeorev.2015.01.013" target="_blank" >10.1016/j.oregeorev.2015.01.013</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Re-Os isotopic constraints on the source of platinum-group minerals (PGM) from the Vestřev pyrope-rich garnet placer deposit, Bohemian Massif

Popis výsledku v původním jazyce

Mineralogical studies of the heavy fraction from a Holocene pyrope-rich garnet placer deposit at Vestřev (Krkonoše Piedmont Basin, Bohemian Massif) have identified the presence of very rare grains of platinum group minerals (PGM). Pt-Fe alloy grains are accompanied by Os-Ir-Ru minerals (native osmium, iridium, and ruthenium) with inclusions of Pt-Fe alloy and hongshiite (PtCu). This mineral assemblage is typical for several mantle settings including ophiolites. The chemistry of the Os-Ir-Ru minerals shows an enrichment of the PGM in Ru,which is typical of ophiolites. The grain morphology of PGM and pyrope-rich garnet (mostly rounded with numerous euhedral/subhedral grains) does not exclude a common source. In-situ laser-ablation MC-ICP-MS was used to measure the Re-Os isotopic compositions of single Os rich grains, which show heterogeneous subchondritic Os isotopic compositions (187Os/188Os = 0.12082 - 0.12505±0.00003). This precludes their low-temperature origin and indicates derivation of platinum-group elements (PGE) essentially from mantle-derived rocks without a significant contribution of crustal Os. The mantle model age (TMA) and Re-depletion model age(TRD) model ages range from ~0.4 to ~1.0 Ga and most likely reflect a long history of meltdepletion that affected the mantle sources of PGM.

Název v anglickém jazyce

Re-Os isotopic constraints on the source of platinum-group minerals (PGM) from the Vestřev pyrope-rich garnet placer deposit, Bohemian Massif

Popis výsledku anglicky

Mineralogical studies of the heavy fraction from a Holocene pyrope-rich garnet placer deposit at Vestřev (Krkonoše Piedmont Basin, Bohemian Massif) have identified the presence of very rare grains of platinum group minerals (PGM). Pt-Fe alloy grains are accompanied by Os-Ir-Ru minerals (native osmium, iridium, and ruthenium) with inclusions of Pt-Fe alloy and hongshiite (PtCu). This mineral assemblage is typical for several mantle settings including ophiolites. The chemistry of the Os-Ir-Ru minerals shows an enrichment of the PGM in Ru,which is typical of ophiolites. The grain morphology of PGM and pyrope-rich garnet (mostly rounded with numerous euhedral/subhedral grains) does not exclude a common source. In-situ laser-ablation MC-ICP-MS was used to measure the Re-Os isotopic compositions of single Os rich grains, which show heterogeneous subchondritic Os isotopic compositions (187Os/188Os = 0.12082 - 0.12505±0.00003). This precludes their low-temperature origin and indicates derivation of platinum-group elements (PGE) essentially from mantle-derived rocks without a significant contribution of crustal Os. The mantle model age (TMA) and Re-depletion model age(TRD) model ages range from ~0.4 to ~1.0 Ga and most likely reflect a long history of meltdepletion that affected the mantle sources of PGM.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10504 - Mineralogy

Projekt

<a href="/cs/project/GA13-15390S" target="_blank" >GA13-15390S: Re-Os geochronologie rudních mineralizací Českého masivu a důsledky pro jejich metalogenezi</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2015

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Ore Geology Reviews

ISSN

0169-1368

e-ISSN

—

Svazek periodika

68

Číslo periodika v rámci svazku

July

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

10

Strana od-do

117-126

Kód UT WoS článku

000350935000008

EID výsledku v databázi Scopus

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