Sedimentological and Surface Characteristics of the Northern and Central Adriatic Sediments

Abstract

The results of this investigation reveal mutual relationship between some sedimentological and surface chemical characteristics, such as granulometric and mineral composition, specific surface area (SSA) and organic matter content, of northern and central Adriatic surface sediments.

Grain size distribution and mineral composition enabled the reconstruction of the sedimentation pattern in the northern and central Adriatic Sea. It was shown that sands are spread in the east, along the Croatian coast. Toward the west, the share of finer sediments increases, so that the western region (parallel to the Italian coast) is covered with pelites. Such a pattern is typical for the northern Adriatic and the 401-407 profile of the central Adriatic. Most of the central region is covered with pelites.

Granulometric and mineral composition are interrelated, indicating that sediments having more clay minerals (aluminosilicates) are always fine-grained, while coarser sediments contain more quartz and carbonates.

The SSA and organic matter content are dependent on the grain size and mineral composition - fine-grained clay minerals have larger SSA’s and contain more organic matter attached to their surface. These organic substances influence considerably the SSA of sediments. It was noted that, after removing the organics, the SSA of sediments changed. This indicates that, effecting the SSA of sediments, organic matter effects their adsorptive ability.