Origin of alkali-rich volcanic and alkali-poor intrusive carbonatites from a common parental magma

Abstract The discrepancy between Na-rich compositions of modern carbonatitic lavas (Oldoinyo Lengai volcano) and alkali-poor ancient carbonatites remains a topical problem in petrology. Although both are supposedly considered to originate via fractional crystallization of a “common parent” alkali-be...

Descripción completa

Guardado en:

Detalles Bibliográficos
Autores principales:	Ivan F. Chayka, Vadim S. Kamenetsky, Nikolay V. Vladykin, Alkiviadis Kontonikas-Charos, Ilya R. Prokopyev, Sergey Yu. Stepanov, Stepan P. Krasheninnikov
Formato:	article
Lenguaje:	EN
Publicado:	Nature Portfolio 2021
Materias:	Medicine R Science Q
Acceso en línea:	https://doaj.org/article/e2cc1931559e4d4cbfd106942aa7ef98
Etiquetas:	Agregar Etiqueta Sin Etiquetas, Sea el primero en etiquetar este registro!

id	oai:doaj.org-article:e2cc1931559e4d4cbfd106942aa7ef98
record_format	dspace
spelling	oai:doaj.org-article:e2cc1931559e4d4cbfd106942aa7ef982021-12-02T15:25:34ZOrigin of alkali-rich volcanic and alkali-poor intrusive carbonatites from a common parental magma10.1038/s41598-021-97014-y2045-2322https://doaj.org/article/e2cc1931559e4d4cbfd106942aa7ef982021-09-01T00:00:00Zhttps://doi.org/10.1038/s41598-021-97014-yhttps://doaj.org/toc/2045-2322Abstract The discrepancy between Na-rich compositions of modern carbonatitic lavas (Oldoinyo Lengai volcano) and alkali-poor ancient carbonatites remains a topical problem in petrology. Although both are supposedly considered to originate via fractional crystallization of a “common parent” alkali-bearing Ca-carbonatitic magma, there is a significant compositional gap between the Oldoinyo Lengai carbonatites and all other natural compositions reported (including melt inclusions in carbonatitic minerals). In an attempt to resolve this, we investigate the petrogenesis of Ca-carbonatites from two occurrences (Guli, Northern Siberia and Tagna, Southern Siberia), focusing on mineral textures and alkali-rich multiphase primary inclusions hosted within apatite and magnetite. Apatite-hosted inclusions are interpreted as trapped melts at an early magmatic stage, whereas inclusions in magnetite represent proxies for the intercumulus environment. Melts obtained by heating and quenching the inclusions, show a progressive increase in alkali concentrations transitioning from moderately alkaline Ca-carbonatites through to the “calcite CaCO3 + melt = nyerereite (Na,K)2Ca2(CO3)3” peritectic, and finally towards Oldoinyo Lengai lava compositions. These results give novel empirical evidence supporting the view that Na-carbonatitic melts, similar to those of the Oldoinyo Lengai, may form via fractionation of a moderately alkaline Ca-carbonatitic melt, and therefore provide the “missing piece” in the puzzle of the Na-carbonatite’s origin. In addition, we conclude that the compositions of the Guli and Tagna carbonatites had alkali-rich primary magmatic compositions, but were subsequently altered by replacement of alkaline assemblages by calcite and dolomite.Ivan F. ChaykaVadim S. KamenetskyNikolay V. VladykinAlkiviadis Kontonikas-CharosIlya R. ProkopyevSergey Yu. StepanovStepan P. KrasheninnikovNature PortfolioarticleMedicineRScienceQENScientific Reports, Vol 11, Iss 1, Pp 1-13 (2021)
institution	DOAJ
collection	DOAJ
language	EN
topic	Medicine R Science Q
spellingShingle	Medicine R Science Q Ivan F. Chayka Vadim S. Kamenetsky Nikolay V. Vladykin Alkiviadis Kontonikas-Charos Ilya R. Prokopyev Sergey Yu. Stepanov Stepan P. Krasheninnikov Origin of alkali-rich volcanic and alkali-poor intrusive carbonatites from a common parental magma
description	Abstract The discrepancy between Na-rich compositions of modern carbonatitic lavas (Oldoinyo Lengai volcano) and alkali-poor ancient carbonatites remains a topical problem in petrology. Although both are supposedly considered to originate via fractional crystallization of a “common parent” alkali-bearing Ca-carbonatitic magma, there is a significant compositional gap between the Oldoinyo Lengai carbonatites and all other natural compositions reported (including melt inclusions in carbonatitic minerals). In an attempt to resolve this, we investigate the petrogenesis of Ca-carbonatites from two occurrences (Guli, Northern Siberia and Tagna, Southern Siberia), focusing on mineral textures and alkali-rich multiphase primary inclusions hosted within apatite and magnetite. Apatite-hosted inclusions are interpreted as trapped melts at an early magmatic stage, whereas inclusions in magnetite represent proxies for the intercumulus environment. Melts obtained by heating and quenching the inclusions, show a progressive increase in alkali concentrations transitioning from moderately alkaline Ca-carbonatites through to the “calcite CaCO3 + melt = nyerereite (Na,K)2Ca2(CO3)3” peritectic, and finally towards Oldoinyo Lengai lava compositions. These results give novel empirical evidence supporting the view that Na-carbonatitic melts, similar to those of the Oldoinyo Lengai, may form via fractionation of a moderately alkaline Ca-carbonatitic melt, and therefore provide the “missing piece” in the puzzle of the Na-carbonatite’s origin. In addition, we conclude that the compositions of the Guli and Tagna carbonatites had alkali-rich primary magmatic compositions, but were subsequently altered by replacement of alkaline assemblages by calcite and dolomite.
format	article
author	Ivan F. Chayka Vadim S. Kamenetsky Nikolay V. Vladykin Alkiviadis Kontonikas-Charos Ilya R. Prokopyev Sergey Yu. Stepanov Stepan P. Krasheninnikov
author_facet	Ivan F. Chayka Vadim S. Kamenetsky Nikolay V. Vladykin Alkiviadis Kontonikas-Charos Ilya R. Prokopyev Sergey Yu. Stepanov Stepan P. Krasheninnikov
author_sort	Ivan F. Chayka
title	Origin of alkali-rich volcanic and alkali-poor intrusive carbonatites from a common parental magma
title_short	Origin of alkali-rich volcanic and alkali-poor intrusive carbonatites from a common parental magma
title_full	Origin of alkali-rich volcanic and alkali-poor intrusive carbonatites from a common parental magma
title_fullStr	Origin of alkali-rich volcanic and alkali-poor intrusive carbonatites from a common parental magma
title_full_unstemmed	Origin of alkali-rich volcanic and alkali-poor intrusive carbonatites from a common parental magma
title_sort	origin of alkali-rich volcanic and alkali-poor intrusive carbonatites from a common parental magma
publisher	Nature Portfolio
publishDate	2021
url	https://doaj.org/article/e2cc1931559e4d4cbfd106942aa7ef98
work_keys_str_mv	AT ivanfchayka originofalkalirichvolcanicandalkalipoorintrusivecarbonatitesfromacommonparentalmagma AT vadimskamenetsky originofalkalirichvolcanicandalkalipoorintrusivecarbonatitesfromacommonparentalmagma AT nikolayvvladykin originofalkalirichvolcanicandalkalipoorintrusivecarbonatitesfromacommonparentalmagma AT alkiviadiskontonikascharos originofalkalirichvolcanicandalkalipoorintrusivecarbonatitesfromacommonparentalmagma AT ilyarprokopyev originofalkalirichvolcanicandalkalipoorintrusivecarbonatitesfromacommonparentalmagma AT sergeyyustepanov originofalkalirichvolcanicandalkalipoorintrusivecarbonatitesfromacommonparentalmagma AT stepanpkrasheninnikov originofalkalirichvolcanicandalkalipoorintrusivecarbonatitesfromacommonparentalmagma
_version_	1718387298124431360

Origin of alkali-rich volcanic and alkali-poor intrusive carbonatites from a common parental magma

Ejemplares similares