Texture of Modern Deltaic Sediments of Godavari River (India): ABSTRACT

Abstract

Textures of modern sediments collected from distributary and tidal channels, lagoon, mangrove swamps, coastal beach and dunes, offshore barrier, and deep-marine facies of the Godavari delta differ significantly from place to place. Distributary-channel sediments are characterized by textures ranging from well-sorted sand to poorly sorted mud, and from positively skewed to negatively skewed sediments. The lagoonal sediments generally are poorly sorted and positively skewed. Their texture is believed to have resulted from mixing small amounts of present-day poorly sorted silt and clay with a well-sorted primary sand mode which is inferred to have been deposited earlier in a littoral environment. Coastal beach sands are moderately sorted and slightly negatively skewed. The d ne sands are well sorted and slightly positively skewed. In contrast, the barrier sands are very well sorted and the skewness curve is nearly symmetrical. Beach sands differ from dune sands by having relatively larger amounts of silt plus clay-size particles. Mangrove swamps have silty clay to clay sediments, whereas all sediments from the deep-marine facies of the Godavari delta are clay. The difference between the paludal and deep-marine clays End_Page 733------------------------------ is the relatively high content of particles of less than 1µ size in the latter. It is concluded that the observed variations in the texture of the sediments from various environments of the Godavari delta may serve as criteria in the recognition of environments of deposition of a paleodelta. End_of_Article - Last_Page 734------------