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Titel |
Thenardite after mirabilite deposits as a cool climate indicator in the geological record: lower Miocene of central Spain |
VerfasserIn |
M. J. Herrero, J. I. Escavy, B. C. Schreiber |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1814-9324
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Digitales Dokument |
URL |
Erschienen |
In: Climate of the Past ; 11, no. 1 ; Nr. 11, no. 1 (2015-01-05), S.1-13 |
Datensatznummer |
250117114
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Publikation (Nr.) |
copernicus.org/cp-11-1-2015.pdf |
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Zusammenfassung |
Salt deposits are commonly used as indicators of different paleoclimates and
sedimentary environments, as well as being geological resources of great
economic interest. Ordinarily, the presence of salt deposits is related to
warm and arid environmental conditions, but there are salts, like mirabilite,
that form by cooling and a concentration mechanism based on cooling and/or
freezing. The diagenetic transformation of mirabilite into thenardite in the
upper part of the lower Miocene unit of the Tajo basin (Spain) resulted in
the largest reserves of this important industrial mineral in Europe. This
unit was formed in a time period (~18.4 Ma) that, in other basins of
the Iberian Peninsula, is characterized by the existence of particular mammal
assemblages appropriate to a relatively cool and arid climate. Determining
the origin of the thenardite deposits as related to the diagenetic alteration
of a pre-existing mirabilite permits the establishment and characterization
of the sedimentary environment where it was formed and also suggests use as a
possible analog with comparable deposits from extreme conditions such as
Antarctica or Mars. |
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