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| Titel |
Clumped isotope constraints on fluid processes and heat advection during late Variscan brittle failure of carbonate rocks |
| VerfasserIn |
Paul Dennis, Daniel Myhill, Neil Allanach, Alexandra Forman, Alina Marca |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250111277
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| Publikation (Nr.) |
 EGU/EGU2015-11379.pdf |
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| Zusammenfassung |
| Clumped isotope temperatures (T(δ47)) for macroscopic hydrothermal calcite veins from the
Lower Carboniferous limestone of the Peak District, U.K. and the Clare Basin, Ireland
indicate that late Variscan brittle failure is accompanied by high rates of fluid flow and heat
advection along fault surfaces. Moreover, the veins are often zoned with regard to both
temperature and oxygen isotope composition indicating that fluid movement is episodic and
occurs in pulses.
A striking feature of the data sets for both the Peak District and Clare Basin is that veins,
including multiple samples from single veins, plot on well defined two end-member mixing
lines in T-δ18Ofluid space. The data for veins in the Clare Basin indicate that they
precipitated at a temperature between 100°and 160Ë C, and for the Peak District between
30°and 100Ë C. The veins precipitate from a mixed fluid comprised of: (i) a hot,
isotopically evolved end member (T>160Ë C, δ18Ofluid > +12V SMOW) and; (ii) a
cooler, isotopically depleted fluid more characteristic of meteoric groundwaters (T |
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