Discussions on Arabian Gulf ooids

This study applied methods previously used on contemporary ooids to describe recent Arabian Gulf ooids with the aim to better understand their ultra-structure and attendant symbiotic relationship with microorganisms in their immediate environments. Petrographic, morphological, and microscopic techniques were applied to describe samples collected from three sites on an ooid shoal. Observations made on dominant grains (ooids) are size distribution, mineralogy, morphology, internal cortical architecture. Mean grain sizes of ooids for the three stations are 329, 429, and 412 mu m and the samples fall into two textural categories, described as poorly to moderately sorted medium-grained sand, and poorly sorted sand. Microorganisms in symbiotic relationships with the ooids belong to cyanobacteria and foraminifera. They were found boring or attached to the surfaces of the ooids and were taxonomically described. These observations will serve as an update of previous accounts of ooid types in the Arabian Gulf.