Geochemistry on interstitial water of 5 sediment profiles from the Persian Gulf

The landward part of the 7 km wide sabkha at Umm Said, SE Qatar, is filled with a stagnant brine virtually saturated with halite. Recent dolomite occurs in the sabkha sediments, the quantity being fully accounted for by the amount of Mg++ ions lost from the interstitial brine. The existence of a reflux system in the seaward parts of the sabkha was established. It was not, however, possible to gi ve any unequivocal demonstration of the effect of this potential system for dolomitization . Although both a reflux mechanism and Recent dolomite formation occur in this tidal flat, the first process has apparently not influenced the second sufficiently to permit the demonstration of reflux dolomitization.

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.

C14 Ages of sediment from the Rud Hilla delta area, Persian Gulf

Six sediment cores from the submarine delta of the Rud Hilla River in the northern part of the Persian Gulf consist of fine grained,homogeneous Holocene marls. The coarse (> 63 ~) fraction varies from 0.3 - 3.5 %. The cores are 2 - 4 m long and were taken in water depths of 8 - 56 m. In spite of the great similarity and homogeneity of the cored sediments, correspondence analysis (an extension of factor analysis) of the coarse fraction reveals the presence of four distinctive sedimentary facies: (1) a minerogenic facies, 10 km from the estuary; (2) an ophiuroidostracod facies near a lateral margin of the delta, 12 - 15 km from the estuary, (3) a benthic foraminiferal-molluskan facies, in the central part of the delta 20 km from the estuary, and near its seaward margin 120 km from the estuary, (4) a gastropod-epibiotic facies, in an area of relatively slow sedimentation on the border of the delta, 90 km from the estuary. A seventh core, taken near the seaward margin of the delta of the Rud Hilla River, penetrated homogeneous, aragonite-rich mud of late Pleistocene age. Correspondence analysis of the sand fraction of the Pleistocene sediments leads to the definition of two facies that can be readily compared with the facies identified in the Holocene cores.