Investigation of distribution pattern and source of surface sediments in continental shelf of Gulf of Oman

Gulf of Oman continental shelf is a narrow area with 5000 km2. The shore line length from Pakistan and Iran border to Hormoz straight is 500 km[1]. the most of this areabelongs to Iran EEZ and the depth changes between o to 200 meters. Methods: In the MG-2007GoO curies, 478 surface sediments were taken by systematic network(5*5km) from the seabed[2]. The sediments analyses in the sedimentary of GIS for granolometery (sieve analyze for the particle larger than 63 microns and laser particlesaiser for the particle less than 63 microns) [3]calcimetery for carbonate calcium anddolomite determination[4]. Mineralogy with XRD, morphometry and morphoscopy by binocular microscope.Conclusions:After granolometrery analyse some parameters such as mean, median, sorting, skewness, standard deviation in the base of phi were calculated. The result shows thatthere are 11 kinds of sediments[5]. Total of calcium carbonate changes Between 8 to 85 percentages. The Distribution maps of Sediments Texture (Clay, Silt, Sand,Granule, Sediments type, Calcium Carbonate and dolomite) prepared in ArcGIS Software. The result of mineralogy shows that illite and chlorite are important clayminerals and monmorilonite is minor. Quartz, terrigenous limeston, feldspar and mica are major minerals in the sediment. Sediments size decrease from coastal to offshore. More than 30 meters depth, type of sediments is slightly gravely mud. The gravels almost are shell fragments two sourcesof sediment were distinguished. at first deterical sediments (fluvial and eolian) andbiochemical sediments.Results: Continents shelf of Oman has two environmentas. detrical and biochemical. Biochemical environments almost are patch coral reefs these patch reefs located in the chabahar embayment, tang, Meidani and jask areas.

کلیدواژه ها:

Gulf of Oman ، Continental shelf ، Sediments type ، Detrical environment ، Carbonate environment