Abstract
Four beaches on the southeastern coast of Cape Ann were studied to determine sediment source, transport, and depositional patterns. Methods of analysis included beach profiling, sediment sampling, and simulated wave refraction. Wave energy, resulting primarily from northeast storms and the prevailing southwesterlies, concentrates on nearshore island and headland complexes. Due to wave refraction, northeast flowing longshore currents are found at Long, Cape Hedge and Pebbly Beaches. At Good Harbor, longshore drift is predominantly southwestward. The wave energy and refraction patterns determine beach gradients and grain size distribution. Predominate direction of longshore drift and systematic internal decreases in grain sizes support a spit formation for the baymouth barrier beaches. Sand-size sediments are primarily glacial in origin and secondarily a result of erosion of the crystalline headlands. The source of cobbles at Cape Hedge and Pebbly Beaches is believed to he a moraine which intersects the shoreline at Cape Hedge.
