Magnetic Properties Of Beach Surface Sediment In Qingdao And Its Environmental Implications

Beach is endowed with human nature of precious natural resources, is the mostactive role in the land and sea areas, the pleasant scenery as people’s leisure travelsites and produce economic benefits, its special geographic location can block thewaves on the impact of the construction land, farmland and road, protect the humanliving space. But the beach erosion is a common problem, beach erosion is the processof a source to send, the mastery of beach sediment characteristics, the correctunderstanding of beach sediment hydrodynamic environment and process andscientific protection is particularly important.Sediment magnetic properties generally can be reflected through the magneticmineral content, types and particle size, and these factors and the sediment source andmigration, sedimentary dynamic action and secondary changes after depositionconditions are closely related, so the magnetic properties of sediments accumulatecontaining abundant environmental information. In this paper, we choose threefamous bath beaches as the research object in Qingdao: The First Bath Beach, TheSecond Bath Beach and Shilaoren Beach. Through studying the beaches’s magneticfeatures, sediment particle size and magnetic mineral composition, in combinationwith the hydrodynamic conditions, maybe we could investigate the relationshipbetween the beach sediment magnetic and granularity, and reflected by sedimentarydynamics and environmental significance.Beach volume magnetic susceptibility spatial distribution has a certain regularity:in the direction parallel to the coast, high magnetic susceptibility values appear inerosion area, relatively low in the sedimentary area; In vertical direction of the coast,high magnetic susceptibility values appear at the top of the berm with the flow area,near to the sea to the land two directions were decreased, the minimum value andmagnetic susceptibility in the beach face area is the most stable. Due to the effect ofwinter summer monsoon climate, winter northwest wind beach surface low density of fine sediment transport to the sea, the high density of heavy mineral, such as magneticmineral stranding, summer in the opposite direction. So winter northwest appearsmaller magnetic susceptibility of high value area, and summer southeast area appearsmaller magnetic susceptibility high value area. By flow from east to west coast, thesouth beach erosion area, high magnetic susceptibility values; As sedimentary area inthe west and magnetic susceptibility value is low.Shilaoren beach sediment granularity characteristic is: lower granularity ofsediment than on beach, a finer berm area. Southwest of sediment particle size fromthe beach area to the middle area became smaller, to the northeast region andgradually become bigger, sorting characteristics from the southwest area to the middlearea is gradually getting better, and from the middle area to the northeast areagradually becomes poor. The whole beach granularity is roughly zonal distribution.Winter beach sediment particles is given priority to with the coarse sand, sedimentparticle separation medium, the summer is given priority to with the fine sand,sediment particle separation is better. Magnetic susceptibility values of samples withdifferent graded sand have obvious difference, the particle size of0.063~0.125mmof fine particles of magnetic susceptibility value is much higher than other grade (high)1~2order of magnitude, this is due to the control beach magnetic magnetic minerals,such as magnetite particles mainly focused on the particle size of0.063~0.125mmof fine particles.Through magnetic mineral extraction, identification under the microscope andelectron probe analysis found that the beach magnetic minerals are mainly magnetite,followed by titanium iron ore, and a small amount of hematite.