Mass transport-dominated sedimentation in a foreland basin, the Hidaka Trough, northern Japan

[1] Mass transport is an important process of sediment redistribution from shallow to deep sea basins. It is vital to understand this process for disaster prevention and protection of economic interests in coastal and offshore areas. We describe mass transport-dominated sedimentation in an active foreland basin, the Hidaka Trough, which developed from collision between the northeastern Japan arc and the Kuril arc. The basin is deformed by east-west compression associated with large, frequent earthquakes. The trough is filled with thick (>4.5 km) sediments, ranging from coal-bearing Cretaceous terrestrial strata to modern diatomaceous hemipelagic mud and volcanic ash. Bottom-simulating reflectors and the distribution of mud volcanoes, pockmarks, and acoustic wipe-out zones on the seismic records suggest the presence of subsurface gases in the sediments. The basin features stacked mass transport deposits (MTDs), but no channel-levee systems have developed. The MTDs are relatively thin (