Eruptive and magmatic evolution of North Chamo Volcanic Field (southern Ethiopia)

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00025798%3A_____%2F23%3A10168618" target="_blank" >RIV/00025798:_____/23:10168618 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/26722445:_____/23:N0000042

Výsledek na webu

<a href="http://www.jgeosci.org/content/jgeosci.365_Rapprich.pdf" target="_blank" >http://www.jgeosci.org/content/jgeosci.365_Rapprich.pdf</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.3190/jgeosci.365" target="_blank" >10.3190/jgeosci.365</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Eruptive and magmatic evolution of North Chamo Volcanic Field (southern Ethiopia)

Popis výsledku v původním jazyce

A group of pyroclastic cones is dispersed in the North Chamo Volcanic Field, i.e. in the northern surroundings of the Chamo Lake and over neighbouring part of the Nech Sar plains (southern termination of the Main Ethiopian Rift). The activity of scattered cinder cones was partly coeval with that of Tosa Sucha Volcano (Calabrian), but continued also afterTosa Sucha&apos;s extinction until Middle Pleistocene (c. 0.5 Ma). Whereas scoria cones on the Nech Sar plains displayed a rather simple Strombolian eruptive style, the cones located within the northern part of Chamo Lake were characterized by more complex evolution. Ganjulle scoria cone, with a uniform olivine basalt composition, started with a Surtseyan-style eruption, which turned into Strombolian as the volcano grew above the water level. An even more complex history was documented for the Ganta cone. Compositional zoning of pyroclastic rocks is explained by zoned-chamber exhaustion. The transition from magmatic to phreatomagmatic style of the eruption was then most likely linked to syn-eruptive subsidence of the area on the Chamo Lake banks. Subsequent transition back to Strombolian style reflected the growth of the cone above water level.The Sr-Nd-Pb isotopes, together with major-element-based thermodynamic modelling, demonstrate that magmas parental to the North Chamo alkaline volcanic rocks (alkali basalt, through trachybasalt and trachyandesite to trachyte) evolved initially by closed-system fractionation of olivine, later joined by clinopyroxene, spinel and calcic plagioclase. The subsequent stage was characterized by a substantial (c. 25percent by mass) assimilation of country-rock felsic igneous material, perhaps corresponding to the Paleogene ignimbrites.

Název v anglickém jazyce

Eruptive and magmatic evolution of North Chamo Volcanic Field (southern Ethiopia)

Popis výsledku anglicky

A group of pyroclastic cones is dispersed in the North Chamo Volcanic Field, i.e. in the northern surroundings of the Chamo Lake and over neighbouring part of the Nech Sar plains (southern termination of the Main Ethiopian Rift). The activity of scattered cinder cones was partly coeval with that of Tosa Sucha Volcano (Calabrian), but continued also afterTosa Sucha&apos;s extinction until Middle Pleistocene (c. 0.5 Ma). Whereas scoria cones on the Nech Sar plains displayed a rather simple Strombolian eruptive style, the cones located within the northern part of Chamo Lake were characterized by more complex evolution. Ganjulle scoria cone, with a uniform olivine basalt composition, started with a Surtseyan-style eruption, which turned into Strombolian as the volcano grew above the water level. An even more complex history was documented for the Ganta cone. Compositional zoning of pyroclastic rocks is explained by zoned-chamber exhaustion. The transition from magmatic to phreatomagmatic style of the eruption was then most likely linked to syn-eruptive subsidence of the area on the Chamo Lake banks. Subsequent transition back to Strombolian style reflected the growth of the cone above water level.The Sr-Nd-Pb isotopes, together with major-element-based thermodynamic modelling, demonstrate that magmas parental to the North Chamo alkaline volcanic rocks (alkali basalt, through trachybasalt and trachyandesite to trachyte) evolved initially by closed-system fractionation of olivine, later joined by clinopyroxene, spinel and calcic plagioclase. The subsequent stage was characterized by a substantial (c. 25percent by mass) assimilation of country-rock felsic igneous material, perhaps corresponding to the Paleogene ignimbrites.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10505 - Geology

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

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

Rok uplatnění

2023

Kód důvěrnosti údajů

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

Název periodika

Journal of Geosciences

ISSN

1802-6222

e-ISSN

—

Svazek periodika

68

Číslo periodika v rámci svazku

1

Stát vydavatele periodika

CZ - Česká republika

Počet stran výsledku

22

Strana od-do

3-24

Kód UT WoS článku

000936829500002

EID výsledku v databázi Scopus

2-s2.0-85149514576