Journal article
OSL-thermochronometry of feldspar from the KTB borehole, Germany
Swiss Federal Institute of Technology Zurich1
University of California at Los Angeles2
Center for Nuclear Technologies, Technical University of Denmark3
Radiation Physics, Center for Nuclear Technologies, Technical University of Denmark4
University of Lausanne5
Wageningen University & Research6
Aarhus University7
University of Freiburg8
Tel Aviv University9
University of Bern10
...and 0 moreThe 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 29±2 °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 (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 (
Language: | English |
---|---|
Year: | 2015 |
Pages: | 232-243 |
ISSN: | 1385013x and 0012821x |
Types: | Journal article |
DOI: | 10.1016/j.epsl.2015.04.032 |
ORCIDs: | 0000-0003-3095-3868 , Jain, Mayank , Kook, Myung Ho and 0000-0001-5559-1862 |