The décollement in both transects is localized along a stratigraphic unit
(~5.97 Ma) within the lower Shikoku Basin. This horizon is correlative across
both transects through its magnetic susceptibility.
The broad low-chloride zone in the lower Shikoku Basin unit, first identified
at Site 808, progressively decreases across the Muroto Transect. This
landward-freshening trend is due to both enhanced diagenetic reaction and
Our ideas of the tectonic evolution of the Muroto Transect have been dramatically changed. Accretion of a Miocene and Pliocene turbidite package forms the large thrust slice zone (LTSZ). This event is associated with a shift from a transverse sediment transport system that delivered coarse material from the arc to the trench to an axial transport system that delivers sediment down the trench axis from the east. Growth of the prism from the LTSZ to the toe of the slope (40 km) took place rapidly within the past 2 m.y.
Introduction | Table of Contents