Soft Sediment Deformation Structures in the Andaman Flysch Group, Andaman Basin: Evidence for Palaeogene Seismic Activity in the Island Arc

Sandip K. Roy (Department of Earth Sciences, IIT Bombay, India)
Santanu Banerjee (Department of Earth Sciences, IIT Bombay, India)

Berita Sedimentologi
Vol 35, No 1 (2016)

The Andaman Flysch Group is represented by four sedimentary facies: thick sandstone, thin sandstone, heterolith and shale. They were observed in seven outcrops in the Andaman Islands. Soft sediment deformation features like slumps structure/folds, convolute bedding or lamination, load and flame structures, pseudo nodules/ball and pillow structures and dish and pillar structures have been observed with regularity in these facies and independent of facies specifics. The slumps structure/folds, convolute bedding or lamination encased by undeformed beds, sand volcanoes and some load casts/pseudo-nodules shows evidence of being triggered by earthquakes in this convergent margin basin.