Peloides de glauconita y apatito en sedimentos carbonatados mesozoicos del sector oriental de la Zona Subbética (provincia de Alicante).
- L.M. Nieto 1
- J. Jimenez Millán 1
- J.M. Molina 1
- F. Nieto 2
- 1 Departamento de Geología. Universidad de Jaén.
- 2 Departamento de Mineralogía y Petrología. Universidad de Granada.
ISSN: 0213-683X
Year of publication: 1996
Issue: 20
Pages: 1496-1498
Type: Article
More publications in: Geogaceta
Abstract
Glauconite and apatite peloids occur in jurassic and cretaceous bioclast-bearing carbonate rocks from the Algayat-Crevillente Unit (Subbetic Zone). The size and the morphology of peloids are controlled by the bioclasts. Internal texture commonly evidence that the glauconite form nuclei surrounded by apatite. K content is elevated in both stratigraphic positions but higher in the cretaceous glauconites than the jurassic glauconites. Textural and chemical evidence indicate a model of glauconitization with two steps: an early dissolution-crystallization process and a further process of K-enrichment. Low K-content in jurassic glauconites can be explained by the calcitic early diagenetic cementation which stops the second step of glauconitization, while the low Fe content of this glauconites could be a later effect due to a deeper burial diagenesis.