Cambro–Ordovician anatexis and magmatic recycling at the thinned Gondwana margin: new constraints from the Kouřim Unit, Bohemian Massif

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985530%3A_____%2F20%3A00508957" target="_blank" >RIV/67985530:_____/20:00508957 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/00025798:_____/19:00000214 RIV/67985831:_____/20:00508957

Výsledek na webu

<a href="https://jgs.lyellcollection.org/content/177/2/325.abstract" target="_blank" >https://jgs.lyellcollection.org/content/177/2/325.abstract</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1144/jgs2019-037" target="_blank" >10.1144/jgs2019-037</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Cambro–Ordovician anatexis and magmatic recycling at the thinned Gondwana margin: new constraints from the Kouřim Unit, Bohemian Massif

Popis výsledku v původním jazyce

The Kouřim Unit represents one of the largest pre-Variscan meta-igneous complexes in the Bohemian Massif and a geochronological, whole-rock geochemical and Sr-Nd isotopic study was conducted to better understand the magmatic evolution of the Early Paleozoic Gondwana margin. Five orthogneisses yield U-Pb zircon ages ranging from 492 +/- 4 to 484 +/- 2 Ma. Two leucogranites give U-Pb zircon ages of 500 +/- 4 and 485 +/- 2 Ma, interpreted to be inherited from their orthogneiss host rock. Two samples from the metasedimentary host rock are dominated by Neoproterozoic-Cambrian detrital zircons. The abundance of zircon inheritance in the orthogneisses and whole-rock Sr-Nd isotopic composition imply an origin from relatively mature continental crustal material. The subalkaline, subaluminous-slightly peraluminous and high-K calc-alkaline arc-like geochemical signature of the orthogneisses is interpreted as inherited from the recycled Cadomian metasedimentary source and both the magmatic and metasedimentary rocks are correlated with similar occurrences in the adjacent Moldanubicum and Tepla-Barrandian Unit. The Late Cambrian-Early Ordovician magmatic activity is linked to crustal anatexis, which was probably initiated by thermal and gravitational relaxation of the thickened Cadomian arc-type crust, followed by lithospheric thinning assisted by far-field forces. The extensional event led to the formation of a passive margin associated with the opening of the Rheic Ocean.

Název v anglickém jazyce

Cambro–Ordovician anatexis and magmatic recycling at the thinned Gondwana margin: new constraints from the Kouřim Unit, Bohemian Massif

Popis výsledku anglicky

The Kouřim Unit represents one of the largest pre-Variscan meta-igneous complexes in the Bohemian Massif and a geochronological, whole-rock geochemical and Sr-Nd isotopic study was conducted to better understand the magmatic evolution of the Early Paleozoic Gondwana margin. Five orthogneisses yield U-Pb zircon ages ranging from 492 +/- 4 to 484 +/- 2 Ma. Two leucogranites give U-Pb zircon ages of 500 +/- 4 and 485 +/- 2 Ma, interpreted to be inherited from their orthogneiss host rock. Two samples from the metasedimentary host rock are dominated by Neoproterozoic-Cambrian detrital zircons. The abundance of zircon inheritance in the orthogneisses and whole-rock Sr-Nd isotopic composition imply an origin from relatively mature continental crustal material. The subalkaline, subaluminous-slightly peraluminous and high-K calc-alkaline arc-like geochemical signature of the orthogneisses is interpreted as inherited from the recycled Cadomian metasedimentary source and both the magmatic and metasedimentary rocks are correlated with similar occurrences in the adjacent Moldanubicum and Tepla-Barrandian Unit. The Late Cambrian-Early Ordovician magmatic activity is linked to crustal anatexis, which was probably initiated by thermal and gravitational relaxation of the thickened Cadomian arc-type crust, followed by lithospheric thinning assisted by far-field forces. The extensional event led to the formation of a passive margin associated with the opening of the Rheic Ocean.

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

2020

Kód důvěrnosti údajů

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

Název periodika

Journal of the Geological Society

ISSN

0016-7649

e-ISSN

—

Svazek periodika

177

Číslo periodika v rámci svazku

2

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

17

Strana od-do

325-341

Kód UT WoS článku

000537276100007

EID výsledku v databázi Scopus

2-s2.0-85081136852