Depositional Facies and Processes of the Holocene Marine Clay in the Osaka Bay Area, Japan

摘要

Holocene deposits 20 to 30m thick are dis- tributed in Osaka Bay and its surrounding area, and consist of lower coarse-grained fluvial deposits, middle to upper bay-floor muddy deposits, and upper delta and nearshore sandy deposits. The Holocene in this area is characterized by a range from coarse-grained silt to fine-grained sand intercalated in the middle muddy deposits of the marine clay bed (Ma 13). The coarse part was formed by stronger tidal and longshore currents deve- loped during high sea-level period of the post- glacial transgression.