رسوب شناسي سواحل غرب خليج نايبند و رسوبگذاري رسوبات كربناته در بندر صيادي عسلويه

SEDIMENTOLOGY OF THE WEST COASTLINES OF NAYBAND BAY AND THE IMPACT OF CARBONATE SEDIMENTS ON THE SEDIMENTATION IN ASALUYEH FISHERY PORT

Asaluyeh Fishery Port is an old fishery port located in the south-east of the Bushehr Province. The rapid shoreline advancement of the updrift fillet of the main breakwater during soltanpour@kntu.ac.ir 4JLL0 J33—0 * T & A ^ Jj Li^U bʹ J J Lfyj / ) ) OJ Lg~JJ /p-JCuJj iJbuJ past few years and the sedimentation at the port entrance has resulted to substantial difficulties in using the port. The relatively large amount of sedimentation finally affected the navigation at the entrance of the port. Using field observations, sedimentology analyses of the obtained sediment samples and comparisons of hydrographic maps in order to get the rate and direction of the updrift sedimentation, the cause of rapid sedimentation and the source of this sediment have been studied in current paper. Statistical parameters of sediment samples have been calculated and minerology, morphoscopy and morphometery investigations were conducted using a binocular microscope. The results show that while there is not a clear clue of coral source among the sediment samples of the west coast of the sampled site, a large portion of coral segments are observed in the vicinity of the port. The investigation of sediment samples confirms the larger percentage of terrigenous sediments in the past as well as the increase of carbonate sediments in recent years. The field observations and analyses of sediment samples reveal the increase of sediment stress, as one of the most profoundly deleterious impacts on corals, which has resulted to the considerable decrease of patch reefs and the related marine organisms. It is apparent that the reclamations and large construction works have caused the excess of sediment load. This is the cause of considerable increase of carbonate sediment and huge sedimentation at the port. The investigations suggest that construction of a groin and dredging of the harbor is the most suitable option for solving the sedimentation problem in long- term. Keywords: sedimentation, sedimentology, carbonate sediments, Assaluyeh, coral reefs