Missing lawsonite and aragonite found: P–T and fluid composition in meta-marls from the Combin Zone (Western Alps)

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00025798%3A_____%2F21%3A00000137" target="_blank" >RIV/00025798:_____/21:00000137 - isvavai.cz</a>

Výsledek na webu

<a href="https://link.springer.com/article/10.1007%2Fs00410-021-01818-0" target="_blank" >https://link.springer.com/article/10.1007%2Fs00410-021-01818-0</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1007/s00410-021-01818-0" target="_blank" >10.1007/s00410-021-01818-0</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Missing lawsonite and aragonite found: P–T and fluid composition in meta-marls from the Combin Zone (Western Alps)

Popis výsledku v původním jazyce

We report the first findings of several occurrences of lawsonite and metamorphic aragonite in the meta-sediments from the Combin Zone (Piemonte–Liguria ocean, Western Alps), where the early blueschist-facies episode is poorly documented. New field and metamorphic data (thermodynamic modelling and Raman spectroscopy on carbonaceous material) are used to elucidate the P–T evolution and fluid composition of the Combin Zone and investigate the lawsonite growth and breakdown reactions. Two tectonometamorphic units have been identified within the Combin Zone with distinct geometry, lithological content and P–T conditions. In the higher grade unit, metamorphic aragonite occurs as inclusions in titanite. Lawsonite and garnet were stable at peak P–T conditions (~ 16–17 kbar and 460–480 °C) at very low X(CO2) values. Lawsonite is systematically pseudomorphed, but preserves hourglass zoning or internal fabric associated with the prograde ductile deformation. The lower grade unit (~ 8 ± 1 kbar ~ 370–400 °C) is discontinuously exposed along the western base of the continental Dent Blanche nappe and records P–T conditions similar to those recorded by the Dent Blanche nappe. A metamorphic discontinuity is, therefore, documented between the largest part of the Combin Zone on the one hand, and the Dent Blanche nappe on the other hand. The discovery of lawsonite and metamorphic aragonite allows a better understanding of the large-scale metamorphic structure of the Western Alps.

Název v anglickém jazyce

Missing lawsonite and aragonite found: P–T and fluid composition in meta-marls from the Combin Zone (Western Alps)

Popis výsledku anglicky

We report the first findings of several occurrences of lawsonite and metamorphic aragonite in the meta-sediments from the Combin Zone (Piemonte–Liguria ocean, Western Alps), where the early blueschist-facies episode is poorly documented. New field and metamorphic data (thermodynamic modelling and Raman spectroscopy on carbonaceous material) are used to elucidate the P–T evolution and fluid composition of the Combin Zone and investigate the lawsonite growth and breakdown reactions. Two tectonometamorphic units have been identified within the Combin Zone with distinct geometry, lithological content and P–T conditions. In the higher grade unit, metamorphic aragonite occurs as inclusions in titanite. Lawsonite and garnet were stable at peak P–T conditions (~ 16–17 kbar and 460–480 °C) at very low X(CO2) values. Lawsonite is systematically pseudomorphed, but preserves hourglass zoning or internal fabric associated with the prograde ductile deformation. The lower grade unit (~ 8 ± 1 kbar ~ 370–400 °C) is discontinuously exposed along the western base of the continental Dent Blanche nappe and records P–T conditions similar to those recorded by the Dent Blanche nappe. A metamorphic discontinuity is, therefore, documented between the largest part of the Combin Zone on the one hand, and the Dent Blanche nappe on the other hand. The discovery of lawsonite and metamorphic aragonite allows a better understanding of the large-scale metamorphic structure of the Western Alps.

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

2021

Kód důvěrnosti údajů

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

Název periodika

Contributions to Mineralogy and Petrology

ISSN

0010-7999

e-ISSN

—

Svazek periodika

176

Číslo periodika v rámci svazku

8 : 60

Stát vydavatele periodika

DE - Spolková republika Německo

Počet stran výsledku

27

Strana od-do

nestránkováno

Kód UT WoS článku

000677714100002

EID výsledku v databázi Scopus

2-s2.0-85111308348