Multiphase solid inclusions reveal the origin and fate of carbonate-silicate melts in metasomatised peridotite

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216224%3A14310%2F21%3A00119281" target="_blank" >RIV/00216224:14310/21:00119281 - isvavai.cz</a>

Alternative codes found

RIV/00025798:_____/21:00000218

Result on the web

<a href="https://doi.org/10.1016/j.lithos.2021.106309" target="_blank" >https://doi.org/10.1016/j.lithos.2021.106309</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.lithos.2021.106309" target="_blank" >10.1016/j.lithos.2021.106309</a>

Result language

angličtina

Original language name

Multiphase solid inclusions reveal the origin and fate of carbonate-silicate melts in metasomatised peridotite

Original language description

Orogenic peridotite in ultrahigh-pressure ultrahigh-temperature terranes provides increasingly strong evidence of material transfer in a subduction-zone setting, causing the metasomatism and melting of mantle rocks. Multiphase solid inclusions (MSI) trapped in garnet can provide clues to these processes occurring at great depth. The MSI enclosed in garnet in pyroxenite, lherzolite and harzburgite from a drillcore in the Saxothuringian basement in the Variscan Bohemian Massif are dominated by hornblende, barian mica and carbonate (dolomite and magnesite), and they contain a large variety of other phases, including spinel, clinopyroxene, orthopyroxene, garnet II, apatite, monazite, thorianite, graphite, norsethite and barian feldspar, scheelite and sulfides (e.g., pentlandite). We demonstrate, that the bulk chemical composition of the MSI evolves from the MSI trapped in garnet pyroxenite, which was the source of the metasomatising liquids, to the MSI in the host peridotite. Garnet pyroxenite has a carbonate-silicate composition comparable to kimberlite, and represents a rare example of a low-degree supercritical melt derived from a mixed crust-mantle source frozen in the mantle. Its high-pressure fractional crystallization produced a residual melt, enriched in alkalies (Na, K), highly incompatible elements (LILE – Ba, Sr; Th, U), LREE, Ti, W and volatiles (CO2, Cl, F, P), which is now trapped in the MSI in pyroxenite garnet. The MSI in peridotite reflect changes in the physical and chemical characteristics of the metasomatising medium during its reactive infiltration into peridotite through silicate crystallization and interaction with mantle minerals reflecting the type of rock (lherzolite vs. harzburgite). A change from a more silicic, solute-rich melt to a more diluted carbonate-rich liquid gradually enriched in LILE (K, Ba) and volatiles (CO2, Cl) and LREE fractionation with an increasing degree of fluid evolution coincides with the evolution of kimberlitic melts to carbonatitic melts. The low-viscosity carbonate-rich liquids can migrate far and metasomatise a considerable volume of the rock. Our work demonstrates that the MSI trapped in garnet represent a unique tool to trace the chemical and physical characteristics of the liquids that metasomatise the mantle wedge and their evolution.

Czech name

—

Czech description

—

Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10504 - Mineralogy

Project

<a href="/en/project/GA18-27454S" target="_blank" >GA18-27454S: Element transfer in deep subduction environment: constraints from ultrahigh-presssure metamorphic terranes</a><br>

Continuities

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

Publication year

2021

Confidentiality

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

Name of the periodical

Lithos

ISSN

0024-4937

e-ISSN

—

Volume of the periodical

398-399

Issue of the periodical within the volume

October

Country of publishing house

NL - THE KINGDOM OF THE NETHERLANDS

Number of pages

25

Pages from-to

106309

UT code for WoS article

000684298500004

EID of the result in the Scopus database

2-s2.0-85109494948