Abstract

• The study area is located in the northern part of Andaman Sea; bounded by Latitude 13º 25´ N and 15º 40´ N and Longitude 93º 15´ E and 97º 45´ E occupies the south and southwest oceanic area of Myanmar. Ayeyarwady continental shelf is a part of an area of a complex geological setting in Andaman basin, located in the south of Ayeyarwady delta surrounded by land area in north and east. In the present study,the formation and association of glauconite and phosphate were systematically studied. Sand of the study area is arkosic sand and lithic arkosic sand in composition derived from continental block and magmatic arc, subduction complex provenances. In the sediments, the glauconite constitutes 1 – 15.5 % of the total detrital fraction in some stations. The glauconite of biotite origin, fecal pellet conversations, foraminifera cavity fillings and replacements also occur. Phosphate constitutes 1 – 10 % of the sediment as replacement of bioclast, micro coprolite phosphate pellet and cement. The phosphates are formed in the shelf edge and slope where upwelling current favors the formation of phosphate. The association of glauconite and phosphate is and they were formed from during slow sedimentation in transgressive phase forming the condense horizon. Therefore, the shelf, shelf edge and slope area are the best fit for the formation of glauconite and phosphate in the present sea-level condition.