OSL-thermochronometry of feldspar from the KTB borehole, Germany

Détails

ID Serval
serval:BIB_E38D546EBB85
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
OSL-thermochronometry of feldspar from the KTB borehole, Germany
Périodique
Earth and Planetary Science Letters
Auteur⸱e⸱s
Guralnik Benny, Jain Mayank, Herman Frédéric, Ankjærgaard Christina, Murray Andrew S., Valla Pierre G., Preusser Frank, King Georgina E., Chen Reuven, Lowick Sally E., Kook Myungho, Rhodes Edward J.
ISSN
0012-821X
Statut éditorial
Publié
Date de publication
08/2015
Peer-reviewed
Oui
Volume
423
Pages
232-243
Langue
anglais
Résumé
The reconstruction of thermal histories of rocks (thermochronometry) is a fundamental tool both in Earth science and in geological exploration. However, few methods are currently capable of resolving the low-temperature thermal evolution of the upper ∼2 km of the Earth's crust. Here we introduce a new thermochronometer based on the infrared stimulated luminescence (IRSL) from feldspar, and validate the extrapolation of its response to artificial radiation and heat in the laboratory to natural environmental conditions. Specifically, we present a new detailed Na-feldspar IRSL thermochronology from a well-documented thermally-stable crustal environment at the German Continental Deep Drilling Program (KTB). There, the natural luminescence of Na-feldspar extracted from twelve borehole samples (0.1–2.3 km depth, corresponding to 10–70 °C) can be either (i) predicted within uncertainties from the current geothermal gradient, or (ii) inverted into a geothermal palaeogradient of °C km−1, integrating natural thermal conditions over the last ∼65 ka. The demonstrated ability to invert a depth–luminescence dataset into a meaningful geothermal palaeogradient opens new venues for reconstructing recent ambient temperatures of the shallow crust (<0.3 Ma, 40–70 °C range), or for studying equally recent and rapid transient cooling in active orogens (<0.3 Ma, >200 °C Ma−1 range). Although Na-feldspar IRSL is prone to field saturation in colder or slower environments, the method's primary relevance appears to be for borehole and tunnel studies, where it may offer remarkably recent (<0.3 Ma) information on the thermal structure and history of hydrothermal fields, nuclear waste repositories and hydrocarbon reservoirs.
Mots-clé
Space and Planetary Science, Earth and Planetary Sciences (miscellaneous), Geochemistry and Petrology, Geophysics
Web of science
Financement(s)
Fonds national suisse / PZ00P2-148191
Création de la notice
23/11/2015 16:11
Dernière modification de la notice
24/12/2022 6:44
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