Late pleistocene and holocene sedimentation in the central and eastern Persian Gulf

The sandfraction of the sediment was analysed in five cores, taken from 65 m water depth in the central and eastern part of the Persian Gulf. The holocene marls are underlayn by aragonite muds, which are probably 10-11,000 years old. 1. The cores could be subdivided into coarse grained and fine grained layers. Sorting is demonstrated by the following criteria: With increasing median values of the sandfraction - the fine grained fraction decreases within each core; - the median of each biogenic component, benthonic as well as planktonic, increases; - the median of the relict sediment, which in core 1179 was carried upward into the marl by bioturbation, increases; - the percentages of pelecypods, gastropods, decapods and serpulid worms in the sandfraction increase, the percentages of foraminifera and ostracods decrease; - the ratios of pelecypods to foraminifera and of decapods to ostracods increase; - the ratios of benthonic molluscs to planktonic molluscs (pteropods) and of benthonic foraminifera to planktonic foraminifera increase (except in core 1056 and 1179); - the ratio of planktonic molluscs (pteropods) to planktonic foraminifera increases; - the globigerinas without orbulinas increase, the orbulinas decrease in core 1056. Different settling velocities of these biogenic particles help in better understanding the results : the settling velocities, hence the equivalent hydrodynamic diameters, of orbulinas are smaller than those of other globigerinas, those of planktonic foraminifera are smaller than those of planktonic molluscs, those of planktonic molluscs are smaller than those of benthonic molluscs, those of pelecypods are smaller than those of gastropods. Bioturbation could not entirely distroy this "grain-size-stratification". Sorting has been stronger in the coarse layers than in the finer ones. As a cause variations in the supply of terrigenous material at constant strength of tidal currents is suggested. When much terrigenous material is supplied (large contents of fine grained fraction) the sedimentation rates are high: the respective sediment surface is soon covered and removed from the influence of tidal currents. When, however, the supply of terrigenous material is small, more sandy material is taken away in all locations within the influence of terrigenous supply. Thus the biogenic particles in the sediment do not only reflect the organic production, but also the influence of currents. 2. There is no parameter present in all cores that is independently variable from grain size and can be used for stratigraphic correlation. The two cores from the Strait of Hormus were correlated by their sequences of coarse and fine grained layers. 3. The sedimentation rates of terrigenous material, of total planktonic and benthonic organisms and of molluscs, foraminifera, echinoids and ophiuroids are shown in table 1 (total sediment 6.3-75.5 cm/1000 yr, biogenic carbonate 1.9-3.6 cm/1000 yr). The sedimentation rates of benthonic organisms are nearly the same in the cores of the Strait of Hormus, whereas near the Central Swell they are smaller. In the upper parts of the two cores of the Strait of Hormus sedimentation rates are higher than in the deeper parts, where higher median values point to stronger reworking. 4. The sequence of coarse and fine grained intervals in the two cores of the Hormus Strait, attributed to variations in climate, as well as the increase of terrigenous supply from the deeper to the upper parts of the cores, agrees with the descriptions in the literature of the post Pleistocene climate as becoming more humid. The rise of sea level is sedimentologically not measurable in the marly sediments - except perhaps for the higher content of echinoids in the lower part of core 1056. These may be attributed to the influence of a migrating wave-base. 5. The late Pleistocene aragonite mud is very fine grained (> 50%< 2 p) and poor in fossils (0.5-1.8%) biogenic particles of total sediment. The sand fraction consists almost entirely of white clumps, c. 0.1 mm in diameter (1177), composed of aragonite needles and of detrital minerals with the same size (1201). The argonite mud was probably not formed in situ, because the water depth at time of formation was at most 35 m at least 12 m. The sorting of the sediment (predominance of the fine grained sand), the absence of larger biogenic components and of pellets, c. 0.2-0.5 mm in diameter, which are typical for Recent and Pleistocene locations of aragonite formation, as well as the sedimentological conditions near the sampling points, indicate rather a transport of aragonite mud from an area of formation in very shallow waters. Sorting as well as lenticular fabric in core 1201 point to sedimentation within the influence of currents. During alternating sedimentation - and reworking processes the aragonitic matrix was separated from the silt - and sand-sized minerals. The lenses grade into touches because of bioturbation. 6. In core 1056 D2 from Hormus Bay the percentages of organic carbon, total nitrogen and total carbonate were determined. With increasing amounts of smaller grain sizes the content of organic matter increases, whereas the amount of carbonate decreases. The amounts of organic carbon and of nitrogen decrease with increasing depth, probably due to early-diagenetic decomposition processes. Most of the total nitrogen is of organic origin, only about 10% may well be inorganically fixed as ammonium-nitrogen. In the upper part of the core the C/N-ratio increases with increasing depth. This may be connected with a stronger decomposition of nitrogen-containing organic compounds. The general decrease of the C/N-ratios in the lower part of the core may be explained by the relative increase of inorganically fixed ammonium-nitrogen with decreasing content of organic matter.

Sediment fraction analysis and population density of living larger foraminifera in the Persian Gulf (Table 1A, 1B)

Living Heterostegina depressa were found in the Persian Gulf on shallows and sides of islands in the Central Basin. Preliminary culture experiments furnished information on life span, salinity tolerances and population density of species. Reproduction processes (probably asexual) could be observed several times. A possible carbonate production of ca. 150 g/year/m**2 has been estimated.

Historical and other information connected with place in the Persian Gulf /

Lettered on cover: Bombay government records ; Miscellaneous information connected with the Persian Gulf.

U.S. interests in, and policies toward, the Persian Gulf, 1980 [microform] : hearings before the Subcommittee on Europe and the Middle East of the Committee on Foreign Affairs, House of Representatives, Ninety-sixth Congress, second session, March 24, April 2, May 5, July 1, 28, and September 3, 1980.

Reuse of record except for individual research requires license from Congressional Information Service, Inc.

The countries and tribes of the Persian Gulf.

Mode of access: Internet.

On course to Desert Storm : the United States Navy and the Persian Gulf /

Includes bibliographical references and index.

U.S. policy in the Persian Gulf : hearing before the Committee on Foreign Relations, United States Senate, One Hundred First Congress, second session ....

Item 1039-A, 1039-B (MF)

Children and war

Children bear disproportionate consequences of armed conflict. The 21st century continues to see patterns of children enmeshed in international violence between opposing combatant forces, as victims of terrorist warfare, and, perhaps most tragically of all, as victims of civil wars. Innocent children so often are the victims of high-energy wounding from military ordinance. They sustain high-energy tissue damage and massive burns - injuries that are not commonly seen in civilian populations. Children have also been deliberately targeted victims in genocidal civil wars in Africa in the past decade, and hundreds of thousands have been killed and maimed in the context of close-quarter, hand-to-hand assaults of great ferocity. Paediatricians serve as uniformed military surgeons and as civilian doctors in both international and civil wars, and have a significant strategic role to play as advocates for the rights and welfare of children in the context of the evolving 'Laws of War'. One chronic legacy of contemporary warfare is blast injury to children from landmines. Such blasts leave children without feet or lower limbs, with genital injuries, blindness and deafness. This pattern of injury has become one of the post-civil war syndromes encountered by all intensivists and surgeons serving in four of the world's continents. The continued advocacy for the international ban on the manufacture, commerce and military use of antipersonnel landmines is a part of all paediatricians' obligation to promote the ethos of the Laws of War. Post-traumatic stress disorder remains an undertreated legacy of children who have been trapped in the shot and shell of battle as well as those displaced as refugees. An urgent, unfocused and unmet challenge has been the increase in, and plight of, child soldiers themselves. A new class of combatant comprises these children, who also become enmeshed in the triad of anarchic civil war, light-weight weaponry and drug or alcohol addiction. The International Criminal Court has outlawed as a War Crime, the conscription of children under 15 years of age. Nevertheless, there remain more than 300 000 child soldiers active and enmeshed in psychopathic violence as part of both civil and international warfare. The typical profile of a child soldier is of a boy between the ages of 8 and 18 years, bonded into a group of armed peers, almost always an orphan, drug or alcohol addicted, amoral, merciless, illiterate and dangerous. Paediatricians have much to do to protect such war-enmeshed children, irrespective of the accident of their place of birth. Only by such vigorous and maintained advocacy can the world's children be better protected from the scourge of future wars.

Carbon14 ages of surface sediment samples from ther Persian Gulf

A simplified classification of the Holocene sediments based on textures and grain type results in fourteen major units, twelve of which are essentially carbonate in composition. A brief description and photographic illustration of these units, together with the sedimentary and diagenetic processes which have contributed to their formation, is designed to give the reader a broad but valid impression of Persian Gulf sediments. The distribution of the fourteen sediment units throughout the Arabian parts of the basin, although complicated by numerous local bathymetric highs and depressions, is relatively simple. Because the Arabian sea floor slopes progressively from a windward shoreline to the basin center there is increasing protection from wave action towards the center of the basin. As a result sediments grade from skeletal, oolitic and pelletoidal sands (and muds in coastal lagoons) and fringing reefs, through an irregular zone of compound grain sands,into widespread skeletal muddy sands, and finally into basin center muds. These simple relationships vary laterally around the Arabian side of the gulf. Lateral variation is dependant upon orientation of the regional slope with respect to the prevailing NW wind-driven waves, angle of slope, and presence or absence of regional, structurally based barriers.