Genesis of emerald at Lened, NWT

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216224%3A14310%2F17%3A00120381" target="_blank" >RIV/00216224:14310/17:00120381 - isvavai.cz</a>

Výsledek na webu

<a href="https://numerique.banq.qc.ca/patrimoine/details/52327/3081324?docref=gK2VAH3sH8YmdLGneE9jRw" target="_blank" >https://numerique.banq.qc.ca/patrimoine/details/52327/3081324?docref=gK2VAH3sH8YmdLGneE9jRw</a>

DOI - Digital Object Identifier

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Jazyk výsledku

angličtina

Název v původním jazyce

Genesis of emerald at Lened, NWT

Popis výsledku v původním jazyce

The sources of emerald-forming fluids and chromophores at the Lened occurrence were assessed using field relationships, Ar-Ar dating, whole rock geochemistry, stable isotopes (O, C, S), and mineral chemistry; the results clearly show that the similar to 100 Ma (Ar-Ar muscovite) Lened emerald occurrence is a Type I (igneous) emerald deposit and relates to the proximal similar to 100 Ma (Ar-Ar biotite) Lened Pluton. Stable isotope analyses suggest the veins formed from a primarily granite-derived fluid with lesser components of meteoric and shale-equilibrated fluids. Beryllium and other incompatible elements (including W, Sn, and F) concentrated in evolved magmatic fluid that exsolved during the last stages of crystallization of the Lened pluton. Local overpressuring of vein-forming fluids under a brittle carapace of early pyroxene-garnet skarn led to fracture and emplacement of quartz-calcite-beryl-scheelite-tourmaline-pyrite veins. Less than 5% of the beryl can be considered pale bluish green emerald. Vanadium concentration in the emerald averages 1563 ppm; Cr averages 75 ppm, and Sc attains concentrations of 782 ppm. The key emerald chromophore vanadium was mobilized by metasomatic breakdown of V-rich black shales (averaging 2000 ppm V) that underlie the emerald occurrence.

Název v anglickém jazyce

Genesis of emerald at Lened, NWT

Popis výsledku anglicky

The sources of emerald-forming fluids and chromophores at the Lened occurrence were assessed using field relationships, Ar-Ar dating, whole rock geochemistry, stable isotopes (O, C, S), and mineral chemistry; the results clearly show that the similar to 100 Ma (Ar-Ar muscovite) Lened emerald occurrence is a Type I (igneous) emerald deposit and relates to the proximal similar to 100 Ma (Ar-Ar biotite) Lened Pluton. Stable isotope analyses suggest the veins formed from a primarily granite-derived fluid with lesser components of meteoric and shale-equilibrated fluids. Beryllium and other incompatible elements (including W, Sn, and F) concentrated in evolved magmatic fluid that exsolved during the last stages of crystallization of the Lened pluton. Local overpressuring of vein-forming fluids under a brittle carapace of early pyroxene-garnet skarn led to fracture and emplacement of quartz-calcite-beryl-scheelite-tourmaline-pyrite veins. Less than 5% of the beryl can be considered pale bluish green emerald. Vanadium concentration in the emerald averages 1563 ppm; Cr averages 75 ppm, and Sc attains concentrations of 782 ppm. The key emerald chromophore vanadium was mobilized by metasomatic breakdown of V-rich black shales (averaging 2000 ppm V) that underlie the emerald occurrence.

Druh

D - Stať ve sborníku

CEP obor

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OECD FORD obor

10504 - Mineralogy

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2017

Kód důvěrnosti údajů

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

Název statě ve sborníku

MINERAL RESOURCES TO DISCOVER, VOLS 1-4

ISBN

9782981689801

ISSN

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e-ISSN

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Počet stran výsledku

4

Strana od-do

1471-1474

Název nakladatele

Society for Geology Applied to Mineral Deposits

Místo vydání

GENEVA

Místo konání akce

Quebec City, CANADA

Datum konání akce

20. 8. 2017

Typ akce podle státní příslušnosti

WRD - Celosvětová akce

Kód UT WoS článku

000439764100364