Investigating temperature sensitivity of quartz Electron Spin Resonance (ESR) thermochronometry: Insights from the Anadarko Basin (Oklahoma, USA)

Low-temperature thermochronology dates mineral cooling through the upper crust, enabling us to constrain the rate and timing of landscape evolution over a range of spatial-temporal scales (Reiners et al. 2005). However, constraining recent thermal histories over timescales of 10⁵−10⁶ years at temperature ranges between 25 and 75 ^oC remains a challenge owing to a lack of temporal resolution from existing thermochronometers. Deciphering recent time-temperature histories (<100 ^oC, typically encompassing the upper <3 km of the Earth’s crust) is crucial for understanding the interactions between tectonics, erosion and climate over Quaternary timescales. To this end, trapped charge techniques like quartz Electron Spin Resonance (ESR) dating can exploit the low temperature sensitivity (<100 ^oC) of various paramagnetic defect centres (such as the Al and Ti centres) to determine thermal history over the Quaternary period. Thus, offering the potential to fill this temporal gap that otherwise remains elusive to classical thermochronology.  

The potential of quartz ESR thermochronometry has been previously investigated (Scherer et al. 1991; Grün et al. 1999; King et al. 2020 and references therein). However, this method is still in its developmental stages and lacks a robust validation study to calibrate its temperature sensitivity, and thereby the ability of quartz ESR centres to record thermal histories over Quaternary timescales. Towards this objective, we investigate quartz extracted from borehole sediments in the Anadarko Basin (Oklahoma, USA) with a known temperature history (varying vertically from ~30−80 °C; Carter et al., 1998) based on empirical calibration with a stable geothermal gradient. This study presents preliminary investigations on the kinetics of different ESR centres in the quartz samples and examines the challenges and potential of quartz ESR centres in reconstructing temperature histories in natural settings.

References:

Carter et al. 1998. Am Assoc of Petro Geo Bull 82: 291–316. https://pubs.usgs.gov/publication/70020705

Reiners et al. 2005. Rev in Min and Geochem 58 (1): 1–18. https://doi.org/10.2138/rmg.2005.58.1

Grün et al. 1999. J Geophys Res 104(B8): 17531–17549. 10.1029/1999JB900173

King et al. 2020. Geochron 2: 1–15. https://doi.org/10.5194/gchron-2-1-2020

Scherer, T. et al. 1994. KTB Rep. 94-2. B25, Kontinentales Tiefbohrprogramm der Bundesrepublik Deutschland, Niedersächs. Landesamt Bodenforsch.