Extreme alteration by hyperacidic brines at Kawah ben volcano, East Java, Indonesia I Textural and mineralogical imprint

Kawah Ijen volcano, located on the eastern tip of Java and renowned for its large hyperacidic crater lake, poses significant volcanic and environmental hazards to its immediate surroundings. Crater lake brines seep through the flanks of the volcano to form the Banyu Pahit river, which is used in irr...

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Main Authors: van Hinsberg, V, Berlo, K, van Bergen, M, Williams-Jones, A
Format: Journal article
Language:English
Published: 2010
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author van Hinsberg, V
Berlo, K
van Bergen, M
Williams-Jones, A
author_facet van Hinsberg, V
Berlo, K
van Bergen, M
Williams-Jones, A
author_sort van Hinsberg, V
collection OXFORD
description Kawah Ijen volcano, located on the eastern tip of Java and renowned for its large hyperacidic crater lake, poses significant volcanic and environmental hazards to its immediate surroundings. Crater lake brines seep through the flanks of the volcano to form the Banyu Pahit river, which is used in irrigation downstream, resulting in extensive pollution, sharply reduced crop yields and health problems. The impact on the environment comes mainly from the high element load, which is derived from leaching of rocks by the acid fluids and transported downstream. Our detailed study of water-rock interaction in different parts of the Kawah Ijen system indicates that there are three settings for this alteration; the crater lake and Banyu Pahit riverbed, the hydrothermal system below the lake, and the solfatara of the active rhyolite dome. In all three settings, the silicates are leached and altered to amorphous silica in the order olivine + glass > An-rich plagioclase > ortho-pyroxene > clino-pyroxene > Ab-rich plagioclase. In contrast, the alteration of titanomagnetite is characterised by dissolution in the surficial setting, replacement by pyrite and Ti-oxide in the hydrothermal system and pyritisation. +. Ti-mobility in the fumarole conduits. Alteration progresses along crystallographically controlled planes in all phases, and shows strong compositional control in plagioclase and titanomagnetite. No secondary minerals develop, except for minor barite, cristobalite, pyrite and jarosite. This indicates that, despite its high element load, the waters are undersaturated with respect to most secondary minerals typically produced during alteration of these magmatic rocks by acid chloride-sulphate brines, and that water-rock interaction at Kawah Ijen is not a sink of elements, but rather contributes to the element load transported downstream. © 2010 Elsevier B.V.
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spelling oxford-uuid:ca09fcc9-9123-4a74-9a63-0f2bd2a751452022-03-27T07:04:33ZExtreme alteration by hyperacidic brines at Kawah ben volcano, East Java, Indonesia I Textural and mineralogical imprintJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:ca09fcc9-9123-4a74-9a63-0f2bd2a75145EnglishSymplectic Elements at Oxford2010van Hinsberg, VBerlo, Kvan Bergen, MWilliams-Jones, AKawah Ijen volcano, located on the eastern tip of Java and renowned for its large hyperacidic crater lake, poses significant volcanic and environmental hazards to its immediate surroundings. Crater lake brines seep through the flanks of the volcano to form the Banyu Pahit river, which is used in irrigation downstream, resulting in extensive pollution, sharply reduced crop yields and health problems. The impact on the environment comes mainly from the high element load, which is derived from leaching of rocks by the acid fluids and transported downstream. Our detailed study of water-rock interaction in different parts of the Kawah Ijen system indicates that there are three settings for this alteration; the crater lake and Banyu Pahit riverbed, the hydrothermal system below the lake, and the solfatara of the active rhyolite dome. In all three settings, the silicates are leached and altered to amorphous silica in the order olivine + glass > An-rich plagioclase > ortho-pyroxene > clino-pyroxene > Ab-rich plagioclase. In contrast, the alteration of titanomagnetite is characterised by dissolution in the surficial setting, replacement by pyrite and Ti-oxide in the hydrothermal system and pyritisation. +. Ti-mobility in the fumarole conduits. Alteration progresses along crystallographically controlled planes in all phases, and shows strong compositional control in plagioclase and titanomagnetite. No secondary minerals develop, except for minor barite, cristobalite, pyrite and jarosite. This indicates that, despite its high element load, the waters are undersaturated with respect to most secondary minerals typically produced during alteration of these magmatic rocks by acid chloride-sulphate brines, and that water-rock interaction at Kawah Ijen is not a sink of elements, but rather contributes to the element load transported downstream. © 2010 Elsevier B.V.
spellingShingle van Hinsberg, V
Berlo, K
van Bergen, M
Williams-Jones, A
Extreme alteration by hyperacidic brines at Kawah ben volcano, East Java, Indonesia I Textural and mineralogical imprint
title Extreme alteration by hyperacidic brines at Kawah ben volcano, East Java, Indonesia I Textural and mineralogical imprint
title_full Extreme alteration by hyperacidic brines at Kawah ben volcano, East Java, Indonesia I Textural and mineralogical imprint
title_fullStr Extreme alteration by hyperacidic brines at Kawah ben volcano, East Java, Indonesia I Textural and mineralogical imprint
title_full_unstemmed Extreme alteration by hyperacidic brines at Kawah ben volcano, East Java, Indonesia I Textural and mineralogical imprint
title_short Extreme alteration by hyperacidic brines at Kawah ben volcano, East Java, Indonesia I Textural and mineralogical imprint
title_sort extreme alteration by hyperacidic brines at kawah ben volcano east java indonesia i textural and mineralogical imprint
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