Late-stage anhydrite-gypsum-siderite-dolomite-calcite assemblages record the transition from a deep to a shallow hydrothermal system in the Schwarzwald mining district, SW Germany.
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| Title: | Late-stage anhydrite-gypsum-siderite-dolomite-calcite assemblages record the transition from a deep to a shallow hydrothermal system in the Schwarzwald mining district, SW Germany. |
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| Authors: | Burisch, Mathias1 mathias.burisch@mineral.tu-freiberg.de, Walter, Benjamin F.2, Gerdes, Axel3, Lanz, Maximilian2, Markl, Gregor2 |
| Source: | Geochimica et Cosmochimica Acta. Feb2018, Vol. 223, p259-278. 20p. |
| Subjects: | Hydrothermal vents, Anhydrite, Gypsum, Precipitation (Chemistry) |
| Geographic Terms: | Black Forest (Germany) |
| Abstract: | The majority of hydrothermal vein systems of economic interest occur at relatively shallow crustal levels, although many of them formed at significantly greater depths. Their present position is a consequence of uplift and erosion. Although, many aspects of their formation are well constrained, the temporal chemical evolution of such systems during uplift and erosion is still poorly understood. These vein minerals comprise calcite, dolomite-ankerite, siderite-magnesite, anhydrite and gypsum forming the last gangue assemblages in Jurassic and Tertiary sulphide-fluorite-quartz-barite veins of the Schwarzwald mining district, SW Germany. Mineral textures of samples from nine localities reveal that in these sequences, mineral precipitation follows a recurring pattern: early calcite is followed by anhydrite or gypsum, siderite and/or dolomite. This succession may repeat up to three times. In-situ (LA-ICP-MS) U-Pb age dating of 15 carbonates from three subsequent generations of the late-stage vein assemblage yield robust ages between 20 and 0.6 Ma. Each mineral sequence forms in a distinctive period of about 2–5 Ma. These ages clearly relate these late-stage mineral phases to the youngest geological episode of the Schwarzwald, which is associated with the Cenozoic Rhine Graben rifting and basement uplift. Based on thermodynamic modelling, the formation of the observed mineral assemblages required an deeply sourced Mg-, Fe- and SO 4 -rich fluid (b), which was episodically mixed with a shallow crustal HCO 3 -rich fluid (a). As a consequence of fluid mixing, concentrations of Mg, Fe and SO 4 temporarily increased and initiated the formation of the observed sulphate-carbonate mineral sequences. This discontinuous large-scale vertical fluid mixing was presumably directly related to episodes of active tectonics associated with the Cenozoic strike-slip regime of the Upper Rhine Graben. Analogously, episodic fluid mixing is a major key in the formation of older (Jurassic to early Tertiary) Pb-Zn-fluorite-quartz-barite assemblages in the same specific vein systems, albeit involving different fluid compositions. Late-stage hydrothermal (∼20–70 °C) vein assemblages reported in this study record the transition from deep (>2 km) to very shallow (0–1 km) crustal conditions. As a consequence of successive uplift, increasing proportions of shallower and cooler (∼50–70 °C) fluids could take part in such mixing processes. Associated changes in the fluid composition caused the vein mineralogy to change from sulphide-quartz-fluorite-barite to calcite-anhydrite/gypsum-siderite-dolomite, as the system passively ascended closer to the surface. [ABSTRACT FROM AUTHOR] |
| Copyright of Geochimica et Cosmochimica Acta is the property of Pergamon Press - An Imprint of Elsevier Science and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) | |
| Database: | Engineering Source |
| FullText | Text: Availability: 0 |
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| Header | DbId: egs DbLabel: Engineering Source An: 127469784 AccessLevel: 6 PubType: Academic Journal PubTypeId: academicJournal PreciseRelevancyScore: 0 |
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| Items | – Name: Title Label: Title Group: Ti Data: Late-stage anhydrite-gypsum-siderite-dolomite-calcite assemblages record the transition from a deep to a shallow hydrothermal system in the Schwarzwald mining district, SW Germany. – Name: Author Label: Authors Group: Au Data: <searchLink fieldCode="AR" term="%22Burisch%2C+Mathias%22">Burisch, Mathias</searchLink><relatesTo>1</relatesTo><i> mathias.burisch@mineral.tu-freiberg.de</i><br /><searchLink fieldCode="AR" term="%22Walter%2C+Benjamin+F%2E%22">Walter, Benjamin F.</searchLink><relatesTo>2</relatesTo><br /><searchLink fieldCode="AR" term="%22Gerdes%2C+Axel%22">Gerdes, Axel</searchLink><relatesTo>3</relatesTo><br /><searchLink fieldCode="AR" term="%22Lanz%2C+Maximilian%22">Lanz, Maximilian</searchLink><relatesTo>2</relatesTo><br /><searchLink fieldCode="AR" term="%22Markl%2C+Gregor%22">Markl, Gregor</searchLink><relatesTo>2</relatesTo> – Name: TitleSource Label: Source Group: Src Data: <searchLink fieldCode="JN" term="%22Geochimica+et+Cosmochimica+Acta%22">Geochimica et Cosmochimica Acta</searchLink>. Feb2018, Vol. 223, p259-278. 20p. – Name: Subject Label: Subjects Group: Su Data: <searchLink fieldCode="DE" term="%22Hydrothermal+vents%22">Hydrothermal vents</searchLink><br /><searchLink fieldCode="DE" term="%22Anhydrite%22">Anhydrite</searchLink><br /><searchLink fieldCode="DE" term="%22Gypsum%22">Gypsum</searchLink><br /><searchLink fieldCode="DE" term="%22Precipitation+%28Chemistry%29%22">Precipitation (Chemistry)</searchLink> – Name: SubjectGeographic Label: Geographic Terms Group: Su Data: <searchLink fieldCode="DE" term="%22Black+Forest+%28Germany%29%22">Black Forest (Germany)</searchLink> – Name: Abstract Label: Abstract Group: Ab Data: The majority of hydrothermal vein systems of economic interest occur at relatively shallow crustal levels, although many of them formed at significantly greater depths. Their present position is a consequence of uplift and erosion. Although, many aspects of their formation are well constrained, the temporal chemical evolution of such systems during uplift and erosion is still poorly understood. These vein minerals comprise calcite, dolomite-ankerite, siderite-magnesite, anhydrite and gypsum forming the last gangue assemblages in Jurassic and Tertiary sulphide-fluorite-quartz-barite veins of the Schwarzwald mining district, SW Germany. Mineral textures of samples from nine localities reveal that in these sequences, mineral precipitation follows a recurring pattern: early calcite is followed by anhydrite or gypsum, siderite and/or dolomite. This succession may repeat up to three times. In-situ (LA-ICP-MS) U-Pb age dating of 15 carbonates from three subsequent generations of the late-stage vein assemblage yield robust ages between 20 and 0.6 Ma. Each mineral sequence forms in a distinctive period of about 2–5 Ma. These ages clearly relate these late-stage mineral phases to the youngest geological episode of the Schwarzwald, which is associated with the Cenozoic Rhine Graben rifting and basement uplift. Based on thermodynamic modelling, the formation of the observed mineral assemblages required an deeply sourced Mg-, Fe- and SO 4 -rich fluid (b), which was episodically mixed with a shallow crustal HCO 3 -rich fluid (a). As a consequence of fluid mixing, concentrations of Mg, Fe and SO 4 temporarily increased and initiated the formation of the observed sulphate-carbonate mineral sequences. This discontinuous large-scale vertical fluid mixing was presumably directly related to episodes of active tectonics associated with the Cenozoic strike-slip regime of the Upper Rhine Graben. Analogously, episodic fluid mixing is a major key in the formation of older (Jurassic to early Tertiary) Pb-Zn-fluorite-quartz-barite assemblages in the same specific vein systems, albeit involving different fluid compositions. Late-stage hydrothermal (∼20–70 °C) vein assemblages reported in this study record the transition from deep (>2 km) to very shallow (0–1 km) crustal conditions. As a consequence of successive uplift, increasing proportions of shallower and cooler (∼50–70 °C) fluids could take part in such mixing processes. Associated changes in the fluid composition caused the vein mineralogy to change from sulphide-quartz-fluorite-barite to calcite-anhydrite/gypsum-siderite-dolomite, as the system passively ascended closer to the surface. [ABSTRACT FROM AUTHOR] – Name: AbstractSuppliedCopyright Label: Group: Ab Data: <i>Copyright of Geochimica et Cosmochimica Acta is the property of Pergamon Press - An Imprint of Elsevier Science and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.</i> (Copyright applies to all Abstracts.) |
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| RecordInfo | BibRecord: BibEntity: Identifiers: – Type: doi Value: 10.1016/j.gca.2017.12.002 Languages: – Code: eng Text: English PhysicalDescription: Pagination: PageCount: 20 StartPage: 259 Subjects: – SubjectFull: Hydrothermal vents Type: general – SubjectFull: Anhydrite Type: general – SubjectFull: Gypsum Type: general – SubjectFull: Precipitation (Chemistry) Type: general – SubjectFull: Black Forest (Germany) Type: general Titles: – TitleFull: Late-stage anhydrite-gypsum-siderite-dolomite-calcite assemblages record the transition from a deep to a shallow hydrothermal system in the Schwarzwald mining district, SW Germany. Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: Burisch, Mathias – PersonEntity: Name: NameFull: Walter, Benjamin F. – PersonEntity: Name: NameFull: Gerdes, Axel – PersonEntity: Name: NameFull: Lanz, Maximilian – PersonEntity: Name: NameFull: Markl, Gregor IsPartOfRelationships: – BibEntity: Dates: – D: 15 M: 02 Text: Feb2018 Type: published Y: 2018 Identifiers: – Type: issn-print Value: 00167037 Numbering: – Type: volume Value: 223 Titles: – TitleFull: Geochimica et Cosmochimica Acta Type: main |
| ResultId | 1 |
