This paper presents the following three topics among new findings on reservoir architecture and hydrocarbon potential of submarine channel - levee - fan systems.

Firstly, this paper summarizes characteristics and origin of new intra-channel reservoir architecture “outer-bank bars (OBBs)”. OBBs develop on the outer banks of meander bends of sinuous submarine channels and dip towards the inner banks, a direction of dip opposed to that of point bars or lateral-accretion packages. This paper then discusses possible reservoir quality of OBBs and possibilities of occurrence of OBBs in fluvial channels.

Secondly, this paper reviews a recent study in the geometry of submarine levees. The variation in levee thickness perpendicular to the channel shows power-law decay on steeper slopes (>0.6°) and either exponential or logarithmic decay on gentler slopes. Grain size may also control the shape of levees. A threshold in slope gradient is here interpreted as the boundary between subcritical and supercritical flows within turbidity currents flowing over levees. Based on the geometry of submarine levees, new criteria to distinguish sand-prone levees from mud-prone levees are proposed.

Finally, a new facies model of hyperpycnites is presented based on the “rhythmite” beds found on the lobe and the levees of the Toyama Deep Sea Channel in the central Sea of Japan. Hydrocarbon potential of hyperpycnites are also examined by organic carbon analysis of them. On the basis of proposed criteria to identify hyperpycnites, two potential fields of hydrocarbon; the Kutei Basin offshore East Kalimantan and the Niigata-Shin'etsu Basin to Toyama Trough, where hyperpycnites may constitute hydrocarbon source rocks, are suggested. In the latter case, a new hydrocarbon source model, which can explain origin of the “Kubiki type oil”, is presented in this paper.