Suid fossils and sedimentology from the Chaloem Phra Kiat and Phimai sandpits, Nakhon Ratchasima province

Abstract

The suid fossils were recorded in fluvial sediments at the Chaloem Phra Kiat and Phimai Districts, Nakhon Ratchasima Province. In this study, numerous suid fossils were identified systematically by the measurement and description in detail of the external morphology of teeth, and comparison with other related species. Sedimentary facies and facies association from stratigraphy of fluvial depositional environment from sandpits have also been studied.

As a result, sediments from Chaloem Phra Kiat and Phimai sandpits comprise very fine to coarse-grained sand with dominate sedimentary structures of the fluvial deposits. The cumulative stratigraphical thickness of the studied successions was 12-15 m. Seven sedimentary facies have been identified within channel systems, including matrix-supported gravel (Gmg), trough cross-bedded sand (St), ripple cross-laminated sand (Sr), planar cross-bedded sand (Sp), massive mud, silt (Fm), laminated sand, silt and mud (Fl), silt, clay (Fsm). These facies are grouped into Six architectural elements as sandy bedforms (SB), lateral accretion deposits (LA), levee deposits (LV), crevasse channel deposits (CR), floodplain deposits (FF), and abandoned channel fills deposits (FF (CH)), each of which is unique in facies association and architectural elements. All of these sediments represent meandering river systems.

The thirty-eight specimens of suid fossils were collected and identified as belonging to four species: Tetraconodon cf. intermedius, Conohyus cf. sindiense, Propotamochoerus cf. hysudricus, and Hippopotamodon cf. sivalense. All these suid taxa are similar to the Siwalik faunas of Pakistan, suggesting a faunal exchange between the Indian subcontinent and Thailand during the Late Miocene.