engleski

Formation and Mineralogical Characteristics of Marine Sediments

The aim of the lecture is to give a short survey on the origin, formation, and mineral and chemical composition of marine sediments. The lecture is directed to all who might be interested in sedimentalogical and mineralogical processes in the marine environment, including those without formal training in these fields. Marine sediments are defined as any deposit of insoluble and particulate material on the sea floor. These deposits originate from primary rock and soil particles, transported from land to the marine environments by wind, ice, and rivers flows. Their origin can also comprise the remains of marine organisms, products of submarine volcanism, of chemical precipitates from seawater, and materials from outer space. These processes will be discussed in detail. Sedimentation processes determine the physical, chemical and biological conditions on the sea floor and therefore influence the deposition and fate of organic and inorganic matter in natural environments. The major aim of this lecture will be to describe the main types of marine sediments, their origin and mineralogical characteristics, and to discuss the environmental conditions in which they occur. Special attention will be given to recent sedimentation processes and to mineralogical composition of two different sedimentological environments typical for the eastern Adriatic coast. The first is characterized by authigenic precipitation and sedimentation of aragonite particles in Malo and Veliko Jezero of the Island of Mljet (Adriatic Sea, Croatia). These are two semi-enclosed, karstic, saltwater lakes with specific environmental characteristics. This is an example of the significance of biologically mediated inorganic precipitation processes in the formation of recent aragonitic mud in a restricted Mediterranean environment. The second environment is the Raša River estuary (Istrian peninsula), delineated by intensive deposition of river-borne, fine-grained clay particles in a low-wave-energy karstic environment. It represents a unique sedimentological environment offering insight into the land-sea interaction.

sediments; geochemistry

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