Controls on chemical evolution and rare element enrichment in crystallising albite-spodumene pegmatite and wallrocks: Constraints from mineral chemistry

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216224%3A14310%2F20%3A00114506" target="_blank" >RIV/00216224:14310/20:00114506 - isvavai.cz</a>

Result on the web

<a href="https://doi.org/10.1016/j.lithos.2019.105289" target="_blank" >https://doi.org/10.1016/j.lithos.2019.105289</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.lithos.2019.105289" target="_blank" >10.1016/j.lithos.2019.105289</a>

Result language

angličtina

Original language name

Controls on chemical evolution and rare element enrichment in crystallising albite-spodumene pegmatite and wallrocks: Constraints from mineral chemistry

Original language description

Internal differentiation and consequent geochemical evolution in pegmatites are significant processes in the development of economically viable deposits of metal-bearing minerals. Albite-spodumene pegmatites, which represent important resources of Li and Ta worldwide, challenge the general rules of pegmatite petrogenesis as these are nearly homogeneous bodies with little or no intrusion-scale pegmatite zonation. Bulk intrusion concentrations of Li are in the uppermost range obtained by magmatic enrichment experiments, around 2 wt% Li2O, and extensive volumes of saccharoidal or platy albite are present. In Leinster, southeast Ireland, weakly zoned to homogeneous albitised spodumene pegmatites and their wallrocks were studied to compare mineral chemistry variations and understand the internal evolution of pegmatites, characteristics linked to the poor development of zonation, and links between internal evolution and pegmatite-wallrock interactions. Leinster pegmatites present mineralogical, textural and geochemical characteristics coherent with Li-saturation, and possibly supersaturation, prior to crystallisation. Weak border to centre zonation in the thickest bodies can be attributed to geochemically evolved initial melt, likely leading to nearly contemporaneous crystallisation throughout the intrusion and resulting in limited internal geochemical fractionation. Increased abundance of minerals bearing highly incompatible elements (e.g. columbite-group minerals and cassiterite) and network modifiers (e.g. phosphates) in albitite indicates it is a fractionation product from pegmatite crystallisation. Enrichment in incompatible elements B, Li, Rb, Cs and F in spodumene pegmatite exocontacts in different country rock types suggests unmixing of a hydrous fluid from the residual melt after the crystallisation of main pegmatitic assemblages, and that the H2O-rich component was mobilised into country rocks. (C) 2019 Elsevier B.V. All rights reserved.

Czech name

—

Czech description

—

Type

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

CEP classification

—

OECD FORD branch

10504 - Mineralogy

Project

<a href="/en/project/GA19-05198S" target="_blank" >GA19-05198S: Greisenization and albitization - geological processes potentially concentrating some critical raw materials for modern technologies</a><br>

Continuities

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

Publication year

2020

Confidentiality

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

Name of the periodical

Lithos

ISSN

0024-4937

e-ISSN

1872-6143

Volume of the periodical

352

Issue of the periodical within the volume

JAN 2020

Country of publishing house

NL - THE KINGDOM OF THE NETHERLANDS

Number of pages

19

Pages from-to

1-19

UT code for WoS article

000515201500023

EID of the result in the Scopus database

2-s2.0-85075884610