Anatomy of a forearc submarine fan: Upper Eocene-Oligocene Andaman Flysch Group, Andaman Islands, India

Detailed facies analysis in the upper Eocene-Oligocene Andaman Flysch Group reveals fourteen different facies, grouped into three different associatio ns. These facies associations represent two anatomical divisions of a subma rine fan, viz. inner fan and depositional lobe in middle fan. Paleocurrent pattern, high percentage of quartz in the sandstones and outer are derived clasts in the inner fan channel conglomerates suggest dual sediment supply in this fan. A longitudinal geometry of the basin has been inferred where j uxtaposition of sediments of different proximality deterred development of any definite sequence pattern. A tectonically induced active sediment suppl y in a rising sea level stand is thought to be responsible for development of the fan.