Kwingu Fm

Irrawaddy River Delta, the type section is at Kwinguyupa village (16° 05′ N, 94° 12′ E) and is well exposed over a distance of 6.4 km (4 miles) in the coastal area, between Kwinguyupa village and Needle Point. [Original Publication: Barber, A. J., Khin Zaw & Crow, M. J. (eds) 2017. Myanmar: Geology, Resources and Tectonics. Geological Society, London, Memoirs, 48, 219–260]

[Figure: Map showing location of sub-basins of the Central Myanmar Basin (after Myint Thein and M. Maung 2017)]

Claystone. The Fm consists of sandstone with grit and pebble lenses at the base, and strongly deformed, dark ash-grey to chocolate-brown claystones. The shale beds are very hard and, in many places, highly carbonaceous. Large quantities of coal fragments are observed in the shale and siltstone beds. Exotic blocks of basalt, micritic limestone, chert and andesite, with sizes ranging from boulders up to 24.5 m (80 ft), occur along the coast from Kwingu Yupa to Needle Point. It is of thickness 1158 m (2800 ft), is the lowest Fm exposed at Chaungthar.

The typical Paleocene alga Distichoplax biserialis sp. was observed south of the Kwinbet stream (Paw Tun et al. 1974).

Mass-flow deposits were predominant during the deposition of the Kwingu Fm