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Pujos, M; Pons, Jc; Parra, M. |
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. |
Tipo: Text |
Palavras-chave: Guyane française; Plages; Cordons sableux; Minéraux lourds; French Guiana; Beaches; Beach ridges sands; Heavy minerals. |
Ano: 2001 |
URL: http://archimer.ifremer.fr/doc/00291/40271/38643.pdf |
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Villacrés, J.; Goyes A., P.. |
En este trabajo se presentan los resultados de los análisis realizados sobre los sedimentos superficiales de fondo en Bahía Chile, Isla Greenwich, desde el punto de vista granulométrico y mineralógico. En un total de 18 muestras del área se observa una predominancia de limos muy mal seleccionados, platicúrticos y con asimetría hacia los tamaños finos. Mineralógicamente, se observa mayor concentración de minerales livianos sobre los pesados, con altos porcentajes de fragmentos de rocas igneas, deduciéndose que son sedimentos inmaduros y que el área fuente se encuentra en una zona cercana. Los sedimentos depositados en la bahía son de orígen mixto: Procedentes de la erosión de las formaciones costeras y en menor porcentaje, del aporte de organismos marinos.... |
Tipo: Journal Contribution |
Palavras-chave: Granulometry; Mineralogy; Sediment mixing; Heavy minerals; Igneous rocks; Light minerals; Mineralogy. |
Ano: 1993 |
URL: http://hdl.handle.net/1834/3770 |
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Jacobs, P.. |
The distribution of heavy minerals in Middle to Upper Eocene deposits of western Belgium is discussed with reference to ternary diagrams based on density (<3.4; 3.4-4.2; >4.2) and mineralogical composition (ubiquist, parametamorphic and garnet-epidote-amphibole-pyroxene groups). A corresponding diamond diagram is used to interpret the transport mode and the energy of the sedimentary environment.The Aalter Formation (middle Eocene), which was deposited in a quiet to turbulent setting, contains high amounts of ubiquists, parametamorphic minerals and garnets, with a minor epidote and amphibole content. The Maldegem Formation (middle to late Eocene) of deltaic origin, is characterized by the dominance of ubiquists, particularly in the sands and silts.... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Eocene; Heavy minerals; Belgium. |
Ano: 1995 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=2566 |
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