MORPHOLOGY, SEDIMENTOLOGY, AND MINERALOGY OF SOUTHERN ISLANDS OF KUWAIT, ARABIAN GULF

The morphological setting of three islands (Kubbar, Qaro and Umm Al-Ma radem) in the northwestern part of the Arabian Gulf are reviewed and a nalyzed. The concept that the formation of these islands are related t o sea level fluctuation is proposed. Their morphological settings impl y the occurrence of two stages of sea-level fluctuations during the Pl iocene-Pleistocene. Textural and mineralogical properties of the recen t surficial sediments of these islands have been investigated. It was observed that the central parts of Kubbar and Umm Al-Maradem (comparat ively larger in size than Qaro) are covered primarily by fine clastics (silty sand), whilst the coarser material (sandy sediments) are gener ally observed in the coastal and some inland areas as well as being th e dominant grain size on Qaro Island. This also implies the effect of the hydrodynamic regime (high-energy zone) which characterizes the sou thern part of Kuwait. The mineralogical investigation of the various s ize fractions of the island's surficial sediments reveals that they ar e polygenetic in origin. Two primary sources for the island sediments were recognized, namely: (a) autochthonous materials derived from the degradation of a variety of invertebrates, especially from the coral c ommunities as well as erosion of submerged ancient sediments and (b) c oral debris which are derived from the surrounding coral communities b y wave action and as a result of SE swell. Fallout from dust storms al so contributes to the sediment budget of these islands.