Figure F22. Conceptual model of the formation of stratigraphic Units III–V at Site U1348. Uppermost panel shows formation of Unit V (layered granular hyaloclastite) through the action of turbidity currents and grain flows on top of the existing structureless, granular hyaloclastites of Unit VI. As deposition of the Unit V hyaloclastites continues and the volcanic slope apron progrades, the dip of the laminated strata decreases from ~20° to <10°. The central panel shows formation of the bioclastic-rich Unit IV. Volcanic activity is diminished at this time, leading to a relatively larger bioclastic element contributing to the sediments. The lowermost panel shows deposition of Unit III layered and graded granular and fine hyaloclastites through the action of a series of high-density turbidity currents.
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