Long-term variations in the granulometric composition and spatial distribution of bottom sediments in the Northern Caspian Sea

Granulometric analysis was carried out for bottom sediment of the Northern Caspian Sea sampled in 2001. The results of analysis were used to map the spatial distribution of different types of bottom sediments and evaluate their areas. To identify the changes that have taken place in the granulometric composition and spatial distribution of bottom sediments in a transgression period, the obtained materials were compared with data of the previous survey. The main factors of sediments dynamics are shown to be higher continental runoff and sea transgression.