Experimental crystallization of a subcalcic Cr-rich pyrope in the presence of REE-bearing carbonatite

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11310%2F19%3A10394507" target="_blank" >RIV/00216208:11310/19:10394507 - isvavai.cz</a>

Výsledek na webu

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=jhZ.i-Rybu" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=jhZ.i-Rybu</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.chemgeo.2019.01.011" target="_blank" >10.1016/j.chemgeo.2019.01.011</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Experimental crystallization of a subcalcic Cr-rich pyrope in the presence of REE-bearing carbonatite

Popis výsledku v původním jazyce

This paper focuses on formation of subcalcic Cr-rich garnet (up to 14.25 wt% Cr2O3) in the model ultramafic system corresponding to natural harzburgite with the presence of REE-bearing fluid phase. The experiments were carried out using a &quot;split-sphere&quot; type multi-anvil high-pressure apparatus (BARS) at a pressure of 5 GPa and a temperature of 1300 degrees C. Natural serpentine, chromite, corundum and REE-carbonatite were used as starting components. Crystallization of garnet occurred in subsolidus conditions by the reaction of orthopyroxene and spinel in the presence of fluid phase. Composition of fluid was controlled by interaction of water released by decomposition of serpentine with carbonate. By using different amounts of carbonatite (0.5 and 1.5 wt%) as a source of calcium and REE, subcalcic Cr-rich garnets with up to 3.5 wt% CaO were crystallized, which are typical for inclusions of harzburgitic paragenesis in natural diamonds. The experiments demonstrated that the rare earth elements (REE) released from the initial carbonatite were transported by the fluid and were incorporated into the newly formed garnet. The distribution of REE in garnet revealed a vivid enrichment toward the heavy REE (HREE), showing the pattern with a very steep slope. These results confirmed high partitioning of HREE into garnet. The present study indicates that the mantle carbonatites, which contain very high proportions of light REE (LREE) to HREE, can play an important role as source material in formation of REE-rich fluids to crystallize garnets with typical REE patterns in mantle peridotites.

Název v anglickém jazyce

Experimental crystallization of a subcalcic Cr-rich pyrope in the presence of REE-bearing carbonatite

Popis výsledku anglicky

This paper focuses on formation of subcalcic Cr-rich garnet (up to 14.25 wt% Cr2O3) in the model ultramafic system corresponding to natural harzburgite with the presence of REE-bearing fluid phase. The experiments were carried out using a &quot;split-sphere&quot; type multi-anvil high-pressure apparatus (BARS) at a pressure of 5 GPa and a temperature of 1300 degrees C. Natural serpentine, chromite, corundum and REE-carbonatite were used as starting components. Crystallization of garnet occurred in subsolidus conditions by the reaction of orthopyroxene and spinel in the presence of fluid phase. Composition of fluid was controlled by interaction of water released by decomposition of serpentine with carbonate. By using different amounts of carbonatite (0.5 and 1.5 wt%) as a source of calcium and REE, subcalcic Cr-rich garnets with up to 3.5 wt% CaO were crystallized, which are typical for inclusions of harzburgitic paragenesis in natural diamonds. The experiments demonstrated that the rare earth elements (REE) released from the initial carbonatite were transported by the fluid and were incorporated into the newly formed garnet. The distribution of REE in garnet revealed a vivid enrichment toward the heavy REE (HREE), showing the pattern with a very steep slope. These results confirmed high partitioning of HREE into garnet. The present study indicates that the mantle carbonatites, which contain very high proportions of light REE (LREE) to HREE, can play an important role as source material in formation of REE-rich fluids to crystallize garnets with typical REE patterns in mantle peridotites.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10505 - Geology

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2019

Kód důvěrnosti údajů

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

Název periodika

Chemical Geology

ISSN

0009-2541

e-ISSN

—

Svazek periodika

509

Číslo periodika v rámci svazku

Březen

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

12

Strana od-do

103-114

Kód UT WoS článku

000459780600007

EID výsledku v databázi Scopus

2-s2.0-85061117092