Marine Mesozoic Rocks in Southern Mae Hong Son Province, Thailand: Paleoenvironmental and Tectonic Setting Implications

DOI: 10.5176/2251-3353_GEOS13.31

Authors: Paweena Seedee and Nutthawut Wonganan

Abstract: Triassic radiolarians were obtained from well-bedded chert sequence in Mae Hong Son areas, northwestern Thailand. This assemblage comprises thirteen species which are Capnuchosphaera triassica, Capnuchosphaera lea, Capnuchosphaera sp., Spongostylus tortilis, Dumitricasphaera cf. goestlingensis, Heliosaturnali transitus, Annulotriassocampe sulovensis, Castrum perornatum, Corum Perfectum, Pachus multinodosus, Triassocampe deweveri, Triassocampe scalaris and Triassocampe nova. The approximate age of this assemblage is Anisian-Norian. Late Triassic (Norian) radiolarians imply the lastest timing of closure of the Paleo-Tethys Ocean.

Keywords: Mesozoic, Triassic, radiolarian, chert, Paleo-Tethys, Shan-Thai, Thailand