Bulletin of the Geological Society of Malaysia, Volume 71, May 2021, pp. 185 – 202
Patcharaporn Ngernkerd1, Montri Choowong1,*, Nutcha Choowong2, Peerasit Surakiatchai1
1 Morphology of Earth Surface and Advanced Geohazards in Southeast Asia Research Unit (MESA RU), Department of Geology, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
2 Chulalongkorn Demonstration School, Faculty of Education, Chulalongkorn University, Bangkok 10330, Thailand
* Corresponding author email address: Montri.firstname.lastname@example.org
Abstract: The preservation of terrestrial dune field in a tropical region is rare and relies significantly on the degree of weathering process, humidity and anthropogenic condition. In this paper, we report the remnants of sand dunes that is uncovered from Thungkula Ronghai (TKR) dune field in the southern part of the Khorat Plateau, northeastern Thailand. We reveal, for the first time, the results of systematic geomorphological, sedimentological and chronological analyzes of barchanoid ridges and parabolic dunes found on terraces of the Mun and the Chi Rivers. Interpretation in a series of 1952 aerial photographs, satellite images coupled with Ground Penetrating Radar (GPR) survey, and optically stimulated luminescence (OSL) dating were applied. As a result, we found remnants of mega-barchanoid ridges and isolated parabolic dunes varying in height from 1-2 m with maximum length of 4 km, locally distributed in between terraces of the Mun and Chi Rivers, the middle to eastern part of TKR. Dune shapes include lobate, en-echelon and elongate partially overlying on crevasse sand splay, meandered scar, paleo-channel, mid-channel bar of the fluvial depositional sequences. Orientation of all dunes is in NW-SE direction reflecting the formation was due to the prevailing NW monsoon wind. Transition from barchanoid ridge to parabolic dune was observed. Preliminary OSL dating reveals the deposition of sand dunes occurred between 45 to 28 ka. This age range can be inferred to a warmer and drier period occurred in Marine Isotope Stage 3 (MIS3) before the Last Glacial Maximum.
Keywords: Parabolic dune, barchanoid ridges, sand splay, Chi River, Khorat Plateau, TKR