Gravel

Definition and Properties of Gravel: Gravel is a loose aggregation of rock fragments. Classified by particle size range, from granule to bouldersized fragments. Different bulk densities and hydraulic conductivity levels. Sometimes distinguished from rubble, which is angular in shape. Various scales define gravel based on particle sizes. Origin and Distribution of Gravel: Derived from the disintegration of bedrock as it weathers. Most common mineral found in gravel is quartz. Deposited in various settings like stream channels, alluvial fans, and marine environments. Widely distributed, mainly as river deposits and glacial deposits. Windformed gravel megaripples in Argentina have similarities to those on Mars. Production and Uses of Gravel: Major raw material in construction industry. Sand and gravel production in the U.S. constituted 23% of industrial mineral production in 2020. Almost half of construction sand and gravel used as aggregate for concrete. Crushed stone is displacing natural gravel in some regions. Types include bank gravel, bench gravel, crushed stone, fine gravel, and pay gravel. Geological Aspects of Gravel: Sediments with over 30% gravel become conglomerate rock. Conglomerates found in sedimentary rock, usually