Znaczenie położenia środka ciężkości w otoczakach dla ich orientacji w osadzie

Abstract

INFLUENCE OF LOCATION OF GRAVITY CENTRE ON ORIENTATION OF PEBBLES IN DEPOSITS Summary The position of centre of gravity in a pebble bears a marked influence on mode of its movement on river bottom. When the position is asymmetrical, the axis A is subjected to repeated changes of orientation in space during transport. Such mode of movement, in turn, influences orientation of the axis A when rolling is suddenly stopped. The change in orientation of the axis A to that consistent with direction of flow (Alia) takes place in gravels with gravity centre markedly translocated towards one of poles of the axis. Other pebbles usually retain their orientation from the time when their transport was stopped. Grains similar in size and of the same class of shape behave in different ways during deposition, depending on position of centre of gravity.