دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

n: a large, sloping sedimentary deposit at the mouth of a canyon, laid down by intermittently flowing water, especially in arid climates, and composed of gravel and sand. The deposit tends to be coarse and unworked, with angular, poorly sorted grains in thin, overlapping sheets. A line of fans may eventually coalesce into an apron that grows broader and higher as the slopes above are eroded away.

land counterpart of a river delta. Characteristic of sediments that have been transported by a fast moving stream then dropped out of the flow as the stream velocity drops as it spreads out. Typical of zones of heavy water runoff such as found at the base