BEACH GRAVEL SHAPE, SPHERICITY, AND ROUNDNESS: OWENS BEACH, PUGET SOUND, WA

Students at the University of Puget Sound collected and measured beach gravels from Owen's Beach at Point Defiance Park in Tacoma, Washington to compare to Gale's (1990) reinvestigation of Bateman's Bay in New South Wales, Australia. Gale found that the shape of the gravels in Batemans Bay were indistinguishable from beach gravels around the world.. Owen's Beach is an extensive beach composed primarily of gravel. Gravel provenance is from the erosion of sediment deposits exposed in cliffs next to the beach. The pebbles are moved around by waves that are generated by wind, the wakes of ships, and currents that affect the shore as they travel through the large fetch between Vashon Island and Owen's Beach. The pebbles' mean shape, sphericity, roundness and O.P Index were measured to compare to Gale's findings in Australia.