(cest2017_00706) The potential of marine aggregate deposits off a highly eroded coastal area in Lesvos Isl. (Greece) - Implications for coastal management

摘要

This paper presents the results of a marine geophysical andsedimentological study carried out offshore of Eresos beach(Lesvos, NE Aegean) to investigate the potential of the areain exploitable Marine Aggregate (MA) deposits that could beused for the nourishment of the eroding beach. Highresolutiondata were acquired using an echo-sounder, a chirpsubbottom profiler (SBP) and surface sediment samples. TheSBP data analysis indicated the presence of a wedge-shapeddeposit probably consisting of medium-coarse-grainedsediments, being up to 8.0 m in thickness. Grain size analysisof the surficial sediments samples revealed a sandy deposit(90-100 % sand) down to water depths of 65 m, with thedominant fraction being fine sand. Mineralogical analysisrevealed that these sediments are similar to the nearby beachsands, with albite being the dominant mineral and quartz themost significant secondary mineral particularly at shallowerwaters. A rough estimation on the basis of the geophysicalevidence indicated a deposit volume of about 3x106 m3 atwater depths between ~30 and 60 m. It appears that the areais a promising site for MAs suitable for beach nourishment,but more geological and environmental studies are needed inorder to estimate the quality and volume of the reserve moreaccurately and determine the environmental impacts of theextraction.