Rola wody w zaokrągleniu okruchów skalnych : otoczaków i wietrzeńców

Weathering causes round out of each primary sharp-edged rock fragments rounding its corners et edges. These fragments still in situ in aluvium are transformed into oval - or ball-shaped weathered boulders. Sloped upper weathering zones with rubbing weathered boulders are displaced on the slopes to river beds and see- and lake-ahores. The weathered boulders are transformed into rolling cobbles and rolling clays (some times armed with sand and gravel grains) only when they are rolled in lotic water in river beds or in seas and lakes. So the roundness of the weathered boulders and pebbles is no evidence of their water transportation.