Margin deltas are the last ones that were formed in a shelf break zone, when a sea level has slowdown during last time of a forced regression and the beginning of the success transgression. The margin deltas are abruptly thickened in the zone of shelf break, became thinner landward and basinward. Because they were formed in the shelf edge, they have a relatively high sand/clay ratio, prone to turbidite. In the northern part of the Red River basin, during the Miocene the margin deltas had developed eastward from the plot 103, . from the borehole 103-TH-1X, 103-TG-1X and.
