| The distribution of heavy minerals on beaches and beach ridges sands of French Guiana shows three distinct suites from East to West: amphibole (largely dominant), staurolite, epidote and pyroxene off the Cayenne region, tourmaline and amphibole mainly off the Kourou-Mana, garnet, staurolite and tourmaline off the Mana-Maroni. A very good continuity exists between the assemblages of heavy minerals from the catchment area parent-rocks, the fluviatile sediments, the coastal zone and the shelf. The results of this study indicate and strengthen a local origin for the sandy sediments and do not support a possibility of an Amazonian source. |
