Hydrothermal fluid interaction in basaltic lava units, Kerguelen Archipelago (SW Indian Ocean)

Christophe Renac*, Kyser Kurtis, Peter Bowden, Bertrand Moine, Jean Yves Cottin

*Corresponding author for this work

Research output: Contribution to journalArticle

7 Citations (Scopus)

Abstract

Hydrothermally altered basaltic lava-units in the northern Kerguelen Archipelago contain a wide variety of secondary silicate and carbonate minerals, including zeolites, hydrothermal calcite, dolomite and magnesite, as well as celadonite, orthoclase (adularia) and quartz. Petrography, fluid-inclusion microthermometry, trace-elements geochemistry, Sr isotopes and stable-isotope compositions indicate hydrothermal fluid cells derived from meteoric water interacting with basalts and Rb-rich subvolcanic peralkaline rocks at temperatures ranging from 50 to 200°C associated with the cooling of the lava pile. The calculated δ18O values of meteoric-hydrothermal waters in fossil hydrothermal systems are identical to those in present-day hot springs, suggesting that meteoric recharge was continuous throughout the igneous cooling cycles of the 28-23 Ma older host basalts and the younger 15-5 Ma old peralkaline intrusions. The Kerguelen northern coastline hydrothermal system in the basaltic pile demonstrates that much of the silicate mineralogy and almost all carbonate secondary minerals in altered basalts were derived from meteoric-hydrothermal fluids, rather than products of seawater interaction, or even magmatic-hydrothermal fluids associated with peralkaline intrusions.

Original languageEnglish
Pages (from-to)215-234
Number of pages20
JournalEuropean Journal of Mineralogy
Volume22
Issue number2
DOIs
Publication statusPublished - Mar 2010
Externally publishedYes

Keywords

  • Fluid inclusions
  • Fluid-rock interaction
  • Kerguelen basalt
  • Meteoric-hydrothermal alteration
  • Stable isotopes

Fingerprint Dive into the research topics of 'Hydrothermal fluid interaction in basaltic lava units, Kerguelen Archipelago (SW Indian Ocean)'. Together they form a unique fingerprint.

Cite this