Carbon isotopic composition of terrestrial plant matter in the Upper Cretaceous Geoncheonri Formation, Gyeongsang Basin, Korea: Implications for Late Cretaceous palaeoclimate on the East Asian continental margin

► Terrestrial plant matter (TPM) of the Cretaceous lacustrine deposits was analyzed. ► The δ13CTPM values suggest that the paleoclimate was semi-arid to sub-humid. ► The average δ13CTPM of this study is heavier than those of coeval forearc regions. ► This indicates that continental region was more arid conditions than forearc regions.