3:30 PM - 5:00 PM
[SCG54-P03] Feldspar OSL dating of MIS 5e marine terrace deposits: case study in the Kii Peninsula
Keywords:OSL, feldspar, marine terrace
Marine terraces are formed by regional uplift and sea level change, being useful for estimating uplift rates on geomorphological time scale (103-105 years). However, the emergent ages, and then the uplift rates, are difficult to determine when the sediments include few organic materials and tephra. Optically stimulated luminescence (OSL) dating method on feldspar is useful to date sediments on 103-105-year timescales. Thus, this method has been applied to date marine terrace deposits in the last several years [1-2].
Late Pleistocene marine terraces are widely distributed in the southern Kii Peninsula. However, the ages of these marine terraces were constrained by only stratigraphy because widespread tephra is not detected and absolute dating data are lacked in this area [3]. We applied feldspar OSL dating method to the marine terraces correlated to MIS 5e [4], which are distributed continuously along coasts of the southern Kii Peninsula, to determine absolute age of these terraces. The samples were collected at an outcrop, whose sediments were divided into the very fine sand layer and the covering fine sand layer. The very fine sand layer is >~5 m in thickness and includes many fossil trackways. The covering fine sand layer is ~4 m in thickness and includes parallel-lamina. From these observations, the very fine sand layer and the covering fine sand layer are considered to be deposited on transgressive and maximum periods, respectively. In this presentation, we will present the results of post-IR IRSL dating on felspar.
This study was funded by the Ministry of Economy, Trade and Industry (METI), Japan as part of its R&D supporting program titled “Establishment of Advanced Technology for Evaluating the Long-term Geosphere Stability on Geological Disposal Project of Radioactive Waste (JPJ007597) (Fiscal Years 2018-2022)”.
References: [1] Thiel et al. (2015). Quaternary Geochronology, 29, 16-29. [2] Ito et al. (2017). Geochronometria, 44, 352-365. [3] Koike and Machida (2001). University of Tokyo Press, 122p. [4] Yonekura (1968). Journal of Geography (Chigaku Zasshi), 77, 1-23.
Late Pleistocene marine terraces are widely distributed in the southern Kii Peninsula. However, the ages of these marine terraces were constrained by only stratigraphy because widespread tephra is not detected and absolute dating data are lacked in this area [3]. We applied feldspar OSL dating method to the marine terraces correlated to MIS 5e [4], which are distributed continuously along coasts of the southern Kii Peninsula, to determine absolute age of these terraces. The samples were collected at an outcrop, whose sediments were divided into the very fine sand layer and the covering fine sand layer. The very fine sand layer is >~5 m in thickness and includes many fossil trackways. The covering fine sand layer is ~4 m in thickness and includes parallel-lamina. From these observations, the very fine sand layer and the covering fine sand layer are considered to be deposited on transgressive and maximum periods, respectively. In this presentation, we will present the results of post-IR IRSL dating on felspar.
This study was funded by the Ministry of Economy, Trade and Industry (METI), Japan as part of its R&D supporting program titled “Establishment of Advanced Technology for Evaluating the Long-term Geosphere Stability on Geological Disposal Project of Radioactive Waste (JPJ007597) (Fiscal Years 2018-2022)”.
References: [1] Thiel et al. (2015). Quaternary Geochronology, 29, 16-29. [2] Ito et al. (2017). Geochronometria, 44, 352-365. [3] Koike and Machida (2001). University of Tokyo Press, 122p. [4] Yonekura (1968). Journal of Geography (Chigaku Zasshi), 77, 1-23.