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Your search keyword '"Díaz Martínez, Roberto"' showing total 3 results
Start Over Author "Díaz Martínez, Roberto" Topic weathering
3 results on '"Díaz Martínez, Roberto"'

1. ESTUDIO QUÍMICO-MINERALÓGICO DE LOS PERFILES LATERÍTICOS FERROSIALÍTICOS EN LOS SECTORES TÉNEME, FARALLONES Y CAYO GUAM EN EL NORESTE DE CUBA.

Author

Njila, Tendai and Díaz-Martínez, Roberto

Subjects
*GEOLOGY, *LATERITE, *WEATHERING
Abstract

The results of a chemical-mineralogical study on the ferrosialitic lateritic weathering profiles are presented. Analysis was done using X Ray Fluorescence and Diffraction. The chemical composition of these profiles reflects a typical pattern normally observed within such weathering crusts. The sesquioxides of aluminium, iron are concentrated in the upper parts of the profiles as a result of the leaching of alkalis, alkaline-earth elements, and to a lesser extent, silica. Ferrosialitic lateritic profiles formed on Cretaceous and Paleogene islands arcs consist of secondary minerals such as gibbsite, kaolinite, goethite, hematite and montmorillonite, while those associated with basic and volcanogenic-sedimentary rocks of ophiolitic affinity in Cayo Guam are composed of gibbsite and iron oxides. This study brings new chemical-mineralogical information on the ferrosialitic lateritic profiles associated with rocks of oceanic nature in north- eastern Cuba, which will help in the exploration for industrial minerals, and rocks and their application in industry. [ABSTRACT FROM AUTHOR]

Published
2016
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2. Semi-quantitative mineralogical valuation of the non-nickeliferous weathering crusts in the northeast of Cuba.

Author

Njila, Tendai, Díaz Martínez, Roberto, Proenza Fernández, Joaquín, and Orozco Melgar, Gerardo

Subjects
*WEATHERING, *CLAY, *KAOLINITE, *MINERALOGICAL research, *QUARTZ, *X-ray spectroscopy
Abstract

This study presents a semi-quantitative mineralogical evaluation of the non-nickeliferous weathering crusts in the areas of Baconal, El Culebro, Caimanes and Farallones in the northeast of Cuba. The main objective of this study is to determine the main mineral phases, their vertical distribution and concentration, as well as the degree of mineral transformation in the weathering profiles. Sixteen samples were analyzed by X-Ray Diffraction and the diffractograms were used in qualitative and semi-quantitative phase analyses using ANALYZE and AUTOQUAN programs. The degree of mineral transformation in relation to phase distribution and concentration as weathering progressed was evaluated using the Mineralogical Index of Alteration. The main mineral phases present in Baconal and El Culebro are Kaolinite (50-75%), Kaolinite-Montmorillonite (50-75%), Quartz (25-50%), Plagioclase, mainly Albite (25-50%) and Hematite (<10%). In Caimanes and Farallones the principal mineral phases present are Kaolinite, Hematite, Quartz, Potassic feldspars, mainly as Orthoclase, all with more than 75%, Halloysite (<10%), and Montmorillonite (<10%). Extreme primary mineral transformation is evidenced in the intermediate and upper layers in Baconal, El Culebro and Caimanes (Mineralogical Index of alteration values between 29 and 98 %). This transformation is also evidenced in the whole Farallones profile (98-99 %). In conclusion, the non-nickeliferous weathering crusts in Baconal, El Culebro, Caimanes and Farallones are mainly kaolinitic clays. [ABSTRACT FROM AUTHOR]

Published
2010

3. MODELO GEOLÓGICO DESCRIPTIVO PARA LOS YACIMIENTOS LATERÍTICOS DE Fe-Ni-Co EN LA FAJA OFIOLÍTICA MAYARÍ-BARACOA DE CUBA ORIENTAL.

Author

Ariosa Iznaga, José D., Lavaut Copa, Waldo, Bergues Garrido, Pedro Siboney, and Díaz Martínez, Roberto

Subjects
*MINES & mineral resources, *NATURAL resources, *INFORMATION resources, *MATHEMATICAL models, *LATERITE, *WEATHERING
Abstract

Mineral deposit descriptive models are valuable geological information network usefull to explore and assessment the territories with these atributes in their geologic pattern and makes them perspectives for the discovery of new mineral resources. In this paper a generalized approach is given about weathering as main process in the formation of laterites as well as three proposal of Fe-Ni-Co laterite descriptive models developed on Mayarí-Baracoa Ophiolitic Belt located in Eastern Cuba. [ABSTRACT FROM AUTHOR]

Published
2003

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