Mineral composition of pelitic fraction of dispersed and consolidated sedimentary matter in the white sea

Abstract

Investigation of sedimentation processes led to an understanding of the relationship between consolidated bottom sediments and dispersed sedimentary matter supplied by the different geospheres: atmosphere, cryosphere, hydrosphere, and biosphere. The long-term research work of the Shirshov Institute of Oceanology RAS in the Russian Arctic seas, including the White Sea, enabled to collect aeolian (atmogenic) material, marine and river suspended particulate matter, ice and snow solids, as well as bottom sediments, for a comprehensive study of the sedimentation process. The bulk of sedimentary matter from these environments is composed of dispersed sedimentary matter with micro- and nano-sized particles. The aim of this chapter was to study the dispersed and consolidated mineral phases of fine-grained fraction (from 10 μm to less than 1 μm) in different geospheres of the White Sea. They are as follows: aerosols, river and marine suspended particulate matter, solids carried by snow and ice, as well as surface bottom sediments. The X-ray diffractometry (XRD) and scanning electron microscopy (SEM) were the main instruments of the study. It is established that about half of the finely dispersed mineral phases was composed of clay minerals. The rest of the sedimentary matter was presented by a fine-grained clastic terrigenous material which characterizes the feeding provinces. When passing through the water column to seabed, mineral phases are transformed in different ways.