Some Properties of Brackish Sediments along the Chao Phraya River of Thailand

Abstract

Takaya found two Quaternary brackish clay beds in the lower reaches of the Chao Phraya river through the field survey of outcrops (Takaya, 1971). The matrix color of sediments and the existence of basic ferric sulphate (jarosite) which gives a characteristic yellow color, and gypsum needles were used as the field criteria of the brackish clays. To clarify what chemical properties are connected with these criteria, electric conductivity and salt composition of water extracts from the sediments, existence of oxidizable sulphur, etc. were examined by the present author. Consequently, it was confirmed that the two brackish clay beds were further subdivided. In this report the author wishes to present a stratigraphy based on the result of the chemical analyses and to try to correlated it with Takaya's stratigraphy.