Chapter Five Modern Environment and Its Record in Surface Sediments

Abstract

This chapter reviews the data on clay minerals, bulk (light) minerals, and heavy minerals of surface sediments from the marginal seas and the adjacent central Arctic Ocean. The chapter discusses potential source areas and transport processes, which is based on the distribution patterns of these minerals. The chapter explains terrigenous (Non-Biogenic) components in Arctic Ocean surface sediments and organic-carbon content. Factors controlling terrigenous particle input, transportation, and accumulation on the shelf, the adjacent continental slope and the deep sea of the Arctic Ocean are river discharge, coastal erosion, sea ice and icebergs, ocean currents, gravitational flows, and, although of minor importance, aeolian supply. The amount and composition of particulate organic-carbon (OC) preserved in the sedimentary records are controlled by different factors such as terrigenous input, primary production, transformation processes in the water column and at the seafloor as well as bulk sedimentation rates. The chapter states that the modern Arctic Ocean OC accumulation is strongly controlled by terrigenous input, in contrast to the other world oceans. Owing to the high fluvial and coastal erosion sediment supply, terrigenous OC is predominant in the Kara, Laptev, and Beaufort seas as well as the central Arctic Ocean.