By river, ocean, or wind, rocks round the same way

By river, ocean, or wind, rocks round the same way River rocks tend to be rounded, as do grains of dune sand and beach glass. Geophysicist Douglas Jerolmack of the University of Pennsylvania led a team in showing that all of these types of particles acquire a curved shape in a similar manner. The finding may help scientists understand how floodplains are built and predict when ash or dust clouds are likely to form. https://ift.tt/eA8V8J