Assessment of tectonic stability in the southwestern part of the Korean Peninsula through the investigation of coastal sediments
Abstract
The eastern part of the Korean Peninsula, which locates in the eastern margin of the Eurasia continent, is known to have been uplifted since the Early Tertiary. In contrast, little is known about the tectonic history of the southwestern of the peninsula. There are three hypotheses on the tectonic movements since the last interglacial period: The southwestern part has been (1) subsided, (2) uplifted together with the eastern part, and (3) tectonically stable. To resolve this problem, we investigated the physicochemical characteristics and estimated depositional age of the coastal sediments in the southwestern peninsula : the Sinji-do Island (SJ), Soan-do Island (SA), and Haenam-gun areas (HN). We found that the coastal sediments in SJ (3 to 5 m a.m.s.l.) and SA (5 and 13 m a.m.s.l.) are paleo beach sediments and reworked marine sediments, respectively. In contrast, the sediments in HN (about 22 m a.m.s.l.) are interpreted as aeolian deposits. Their depositional ages were estimated 115.9 to 127.5 ka, 60.2 and 94.0 ka, and 104.5 to 136.1 ka, respectively. Our results imply that the sea level during the Marine Isotope Stage (MIS) 5e in the study area had risen more than 3 to 5 m a.m.s.l. The sea level variation is consistent with the eustatic sea level change during the MIS 5e. Therefore, we support the assumption of the tectonically stability in the southwestern part of the Korean Peninsula since the MIS 5e.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFMEP11E2104S
- Keywords:
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- 3020 Littoral processes;
- MARINE GEOLOGY AND GEOPHYSICS;
- 4315 Monitoring;
- forecasting;
- prediction;
- NATURAL HAZARDS;
- 4316 Physical modeling;
- NATURAL HAZARDS;
- 4217 Coastal processes;
- OCEANOGRAPHY: GENERAL