Spatial variability of source composition and petrogenesis in rift and rift flank alkaline lavas from the Eger Rift, Central Europe

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00025798%3A_____%2F17%3A00000015" target="_blank" >RIV/00025798:_____/17:00000015 - isvavai.cz</a>

Výsledek na webu

<a href="http://www.sciencedirect.com/science/article/pii/S0009254116305964" target="_blank" >http://www.sciencedirect.com/science/article/pii/S0009254116305964</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.chemgeo.2016.11.003" target="_blank" >10.1016/j.chemgeo.2016.11.003</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Spatial variability of source composition and petrogenesis in rift and rift flank alkaline lavas from the Eger Rift, Central Europe

Popis výsledku v původním jazyce

Geochemical data on Oligocene melilititic and nephelinitic rocks from the northern Eger Rift flank in Central Europe reveal significant differences to nephelinites and basanites of volcanic complexes in the rift axis. The mafic rift flank lavas are more enriched in TiO2, P2O5 and CaO but have lower SiO2 compared to the alkaline volcanic rocks in the Eger Rift. The differences in major element compositions imply (1) lower degrees of partial melting beneath the rift flank than beneath the rift axis evident from lower SiO2 and higher (Ce/Yb)N ratios in the offaxis basalts and (2) different assemblages of fractional crystallization. The mafic rift flank magmas experienced crystal fractionation of olivine followed by clinopyroxene fractionation in contrast to early simultaneous olivine and clinopyroxene fractionation in the magmas below the rift basin. In addition, assimilation of continental crustal rocks is associated with crystal fractionation and changes the composition of the lavas. The rift axis lavas are enriched in Nb and Ba relative to La and have higher Sr and lower Nd isotope ratios than the rift flank magmas indicating different mantle sources. The melting zones beneath the rift axis and the rift flank region are separated although they are only some 20 km apart and no melt exchange between the magma systems is observed. All magmas probably experienced mixing between a deep carbonatitic and a shallower low-degree silicate melt.

Název v anglickém jazyce

Spatial variability of source composition and petrogenesis in rift and rift flank alkaline lavas from the Eger Rift, Central Europe

Popis výsledku anglicky

Geochemical data on Oligocene melilititic and nephelinitic rocks from the northern Eger Rift flank in Central Europe reveal significant differences to nephelinites and basanites of volcanic complexes in the rift axis. The mafic rift flank lavas are more enriched in TiO2, P2O5 and CaO but have lower SiO2 compared to the alkaline volcanic rocks in the Eger Rift. The differences in major element compositions imply (1) lower degrees of partial melting beneath the rift flank than beneath the rift axis evident from lower SiO2 and higher (Ce/Yb)N ratios in the offaxis basalts and (2) different assemblages of fractional crystallization. The mafic rift flank magmas experienced crystal fractionation of olivine followed by clinopyroxene fractionation in contrast to early simultaneous olivine and clinopyroxene fractionation in the magmas below the rift basin. In addition, assimilation of continental crustal rocks is associated with crystal fractionation and changes the composition of the lavas. The rift axis lavas are enriched in Nb and Ba relative to La and have higher Sr and lower Nd isotope ratios than the rift flank magmas indicating different mantle sources. The melting zones beneath the rift axis and the rift flank region are separated although they are only some 20 km apart and no melt exchange between the magma systems is observed. All magmas probably experienced mixing between a deep carbonatitic and a shallower low-degree silicate melt.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10505 - Geology

Projekt

<a href="/cs/project/GAP210%2F12%2F1990" target="_blank" >GAP210/12/1990: Kontinentální litosféra jako zdroj diferencovaných alkalických láv a genetická role bazických magmat vymezení pomocí vulkanismu oherského příkopu</a><br>

Návaznosti

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

Rok uplatnění

2017

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

455

Číslo periodika v rámci svazku

April

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

11

Strana od-do

304-314

Kód UT WoS článku

000405043600020

EID výsledku v databázi Scopus

2-s2.0-85008213629