Water contents and hydrogen isotope compositions of amphibole in aillikites from the Tarim large igneous province, NW China: Insight into Earth’s deep water cycle

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F41601670%3A_____%2F23%3AN0000008" target="_blank" >RIV/41601670:_____/23:N0000008 - isvavai.cz</a>

Alternative codes found

RIV/00216305:26110/24:PU155169 RIV/67985831:_____/24:00578533

Result on the web

<a href="https://doi.org/10.1130/B36906.1" target="_blank" >https://doi.org/10.1130/B36906.1</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1130/B36906.1" target="_blank" >10.1130/B36906.1</a>

Result language

angličtina

Original language name

Water contents and hydrogen isotope compositions of amphibole in aillikites from the Tarim large igneous province, NW China: Insight into Earth’s deep water cycle

Original language description

Water is known to play a crucial role in the generation of many large igneous provinces (LIP) worldwide, but the amount and origin of the water in their sources is still under debate. To address this question, this paper presents in situ major-, trace-element, and Sr isotope data coupled with bulk-mineral O-HHe isotope analyses of amphibole in a suite of aillikites from the Tarim LIP (NW China). The cores of zoned macrocrysts and microcrysts display partially overlapping compositions ranging between edenite and pargasite (75–83 versus 75–80 Mg#), which suggest a common origin from an evolving magma. The rims (Mg# = 75–80) of both macrocrysts and microcrysts are very similar to their cores for many elements, except for higher Sr and Ba contents. All the amphibole zones show similar primitive mantle–normalized trace element patterns, suggesting that they crystallized at different stages during magmatic evolution. This interpretation is confirmed by the homogenous Sr isotope compositions (87Sr/86Sr(i) = 0.70298–0.70394) of these amphiboles, which overlap with those of magmatic apatites and perovskites in these aillikites. The hydrogen isotope compositions (δD = −120‰ to −140‰) of the amphiboles are significantly lower than average mantle values. Given the low water contents (<0.66 wt%) of these minerals, the low H isotope signatures of the amphiboles might be caused by variable H2O loss during magma ascent. However, open-system Rayleigh fractionation modeling suggests that the hydrogen isotope compositions of these amphibole phenocrysts cannot be fully reproduced by crystallization following magmatic degassing. These low δD values require incorporation of recycled altered oceanic crust containing hydrous components in the plume source of these aillikites, which is consistent with the previously published moderately radiogenic He isotope ratios of olivine separates and bulk-rock Os and Pb isotope data for these same samples. We conclude that water in these magmas was derived from a plume source containing recycled water-bearing oceanic crust.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

10505 - Geology

Project

<a href="/en/project/GX19-29124X" target="_blank" >GX19-29124X: EVOLUTION AND POST-EMPLACEMENT HISTORY OF CARBONATITES: IMPLICATIONS FOR THE MOBILITY AND CONCENTRATION OF CRITICAL METALS</a><br>

Continuities

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

Publication year

2023

Confidentiality

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

Name of the periodical

Geological Society of America Bulletin

ISSN

0016-7606

e-ISSN

1943-2674

Volume of the periodical

136

Issue of the periodical within the volume

September 20, 2023

Country of publishing house

US - UNITED STATES

Number of pages

14

Pages from-to

2097-2110

UT code for WoS article

001236797500004

EID of the result in the Scopus database

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