• The Korean Journal of Petroleum Geology
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• v.4 no.1_2 s.5
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• pp.12-19
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• 1996

Directional sedimentary structures (channel structure, cross stratification, and current ripple) were observed in fine to gravelly ye.y coarse sandstones of the Cretaceous Mayans Group (lljig, Hupyeongdong, and Jeomgok formations) in the northeastern part of Euiseong subbasin of Kyongsang basin, Southeast Korea. Large and small scale channel structures are common in all formations. Trough cross-stratification and channel structure frequently occur in the lljig formation (proximal fluvial deposit), whereas planar cross- stratification, cross lamination, and current ripple occur abundantly in the Hupyeongdong and Jeomgok formations (distal braided fluvial to marginal lacustrine deposits). The paleocurrent directions inferred from a statistical analysis of total 43 directional sedimentary structures show a mean azimuth of $290^{\circ}C$ with a standard deviation of $\pm68$. It suggests that the main flow of the paleocurrents moved toward the WNW direction and the source area of the sediments would be located somewhere in the ESE direction beyond the study area.