Características de las mineralizaciones de variscita asociadas a los materiales silúricos del Sinforme de Terena, Encinasola (Provincia de Huelva). Comparación con las de la Provincia de Zamora

  1. María Candelas Moro Benito
  2. Margarita Gil Agero 1
  3. José María Montero 1
  4. María Luisa Cembranos Pérez
  5. Luis Pérez del Villar Guillén
  6. Agustina Fernández Fernández
  7. Elena Hernández Sánchez 1
  1. 1 Universidad de Salamanca (Departamento de Geología)
Boletín de la Sociedad Española de Mineralogía

ISSN: 0210-6558

Year of publication: 1992

Volume: 15

Issue: 0

Pages: 79-89

Type: Article

More publications in: Boletín de la Sociedad Española de Mineralogía


The variscite mineralizations associated with the Silurian siliceous materials of the Terena Synform (Huelva) are, for the first time, described in this work. Two types of variscite mineralizations have been differenciated. The first type is constituted by variscite and strengite, and shows concretionary-concentric-multilaminated textures (oncoids). The second type is fundamentally formed by variscite, is discordant and shows a massive and occasionally botryoidal or spherulitic with radiating-fibrous texture. Polarizing microscope and chemical analysis have been used for the host-rocks characterization. In both type of mineralizations, the mineralogical and textural characteristics have been determined by polarizing microscopy, scanning electron microscopy, X-ray diffraction, thermogravimetric analysis, electron microprobe and chemical analyses. The comparison between the mineralizations studied and those of the Alcañices Synform, also hosted in Silurian materials, suggests that the former have a similar origin that these last. So, the stratiform mineralization would have pseudomorphized earlier oncoidal algal structures, during early diagenesis; and the discordant mineralization would come from the former by the hydrothermal remobilization processes related to late diagenesis and/or post-Hercynian faulting phases.