Phosphorite in Georgia continental shelf sediments
Phosphorite in Georgia continental shelf sediments
Geological Society of America Bulletin (1966) 77 (8): 849-858
- Atlantic Ocean
- chemically precipitated rocks
- clastic sediments
- continental shelf
- environment
- Georgia
- marine geology
- mineral data
- phosphate rocks
- provenance
- sand
- sands
- sedimentary petrology
- sedimentary rocks
- sedimentation
- sediments
- United States
- Continental shelf sediments
- Beach
- Coastal plain
- phosphorite provenance
- continental shelf phosphorite grains
- Georgia continental shelf
- shoreward movement
Rounded, polished phosphorite sand grains occur in continental shelf, beach, and estuarine sediments of the coast of Georgia. Both amber and black phosphorite are present and together average one percent of the total sediment. The grain size of the phosphorite and quartz fractions of most samples are similar, and in conjunction with the high polish on phosphorite grains indicate a probable detrital origin of the phosphorite. Since present-day rivers are not contributing phosphorite, it must have been derived from Pleistocene river sources or from outcropping phosphate-rich Miocene(?) sediments on the shelf. The presence of phosphorite in beach and estuarine sands requires that part of this sand be derived by landward transport of sediments from the continental shelf.