1. Hydrothermal fluid interaction in basaltic lava units, Kerguelen Archipelago (SW Indian Ocean)
- Author
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Peter Bowden, Kurtis Kyser, Jean-Yves Cottin, Bertrand Moine, Christophe Renac, Laboratoire de Transferts Lithosphériques (LTL), Université Jean Monnet [Saint-Étienne] (UJM), Laboratoire Magmas et Volcans (LMV), Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet [Saint-Étienne] (UJM)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Department of Geological Sciences and Geological Engineering, Queen's University [Kingston, Canada], Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS), and Université Jean Monnet - Saint-Étienne (UJM)
- Subjects
010504 meteorology & atmospheric sciences ,[SDE.MCG]Environmental Sciences/Global Changes ,Carbonate minerals ,Geochemistry ,stable isotopes ,interaction ,[SDU.STU]Sciences of the Universe [physics]/Earth Sciences ,engineering.material ,010502 geochemistry & geophysics ,01 natural sciences ,Peralkaline rock ,Hydrothermal circulation ,[SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry ,Geochemistry and Petrology ,Fluid inclusions ,14. Life underwater ,meteoric-hydrothermal alteration ,[SDU.STU.HY]Sciences of the Universe [physics]/Earth Sciences/Hydrology ,Kerguelen basalt ,[SDU.STU.AG]Sciences of the Universe [physics]/Earth Sciences/Applied geology ,ComputingMilieux_MISCELLANEOUS ,0105 earth and related environmental sciences ,Basalt ,Igneous rock ,fluid inclusions ,[SDU]Sciences of the Universe [physics] ,[SDE]Environmental Sciences ,Meteoric water ,engineering ,Celadonite ,fluid–rock ,Geology - 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 δ 18 O 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.
- Published
- 2010