Petrography and geochemistry of modern river sediments in
River sands derived from quartzitic sources are dominated by polycrystalline quartz making up to half of the framework Fig 3 C Volcanic rock fragments are not abundant and include lathwork lithics This holds true also for sands directly taken from a crater lake close to Fort Portal sample ID 22 where polycrystalline quartz dominates
Dredging Practices and Environmental Considerations
Dredging and dredged material management consists of the following three elements 1 Excavation The dislodgement and removal of sediments clay silt sand gravel and rock from the bed of the water body by a dredge either mechanically hydraulically or by combination of the two dredging methods