Introduction

Materials on the bottom of lakes, streams, and oceans, known as bottom sediments, originate from soil erosion and precipitation from chemical and biological processes in the water. Depending on their origin, bottom sediments contain particles of different sizes, shapes, and mineralogical and chemical composition. Prior to settling on the bottom, particles are transported in the water and become sorted and deposited according to their textural properties in different areas of the lakes, streams, and oceans. Generally, coarse materials, such as sand and pebbles, settle in the nearshore zone of a lake and in fast flowing streams. Fine-grained particles, such as silt and clay, become deposited in deep waters in areas with restricted currents. The particles accumulate on the bottom at different rates, varying between tenths of millimeters to several centimeters per year.