Rock Luminescence Dating Method for Studying the Temporal and Spatial Evolution of the Maying River, Qilian Mountains

    Fluvial depositional systems are critical for understanding the interplay between tectonics and climate. Accurately determining the ages of these formations is essential for exploring the spatial and temporal evolution of river deposits. In arid and semi-arid regions, these systems predominantly consist of coarse materials and cobbles. Traditional age determination methods often focus on well-sorted fine sediments, while dating poorly sorted cobble layers presents a significant challenge. Recently, optically stimulation luminescence (OSL) is increasingly are used to determine the burial age of rocks. This new method relies on resetting of the latent geological OSL signals with depth into the rock surface, and the re-accumulation of new signals after the burial (Sohbati et al.,2015).

     This study aims to investigate buried cobbles from terrace and alluvial gravel profiles along the Maying River, located at the foothills of the Qilian Mountains. We will utilize a Risø Luminescence Imager, complemented by in-situ measurement techniques (Sellwood et al.,2022). This integrated methodology will enhance our understanding of luminescence signal bleaching characteristics on rock surfaces, allowing for the rapid and accurate selection of samples for age dating. This approach not only mitigates the limitations of cobble dating across millennial to hundred-thousand-year timescales, but also provides novel insights into the late Quaternary geomorphology and tectonic evolution of rivers at the front of the Qilian Mountains.

Key words: Rock surface luminescence dating, Risø Luminescence Imager, Buried age

References

• Sohbati, R., Murray, A.S., Porat, N., Jain, M., Avner, U., 2015. Age of a prehistoric “Rodedian” cult site constrained by sediment and rock surface luminescence dating techniques. Quat. Geochronol. 30, 90-99.
• Sellwood, E. L., Kook, M., Jain, M., 2022, A 2D imaging system for mapping luminescence-depth profiles for rock surface dating. Radiat. Meas. 150, 106697.