Caracterización de los filosilicatos de la sucesión hemipelágica de la Serra dels Almaens (Albiense superior, Prebético de Alicante)

Resumo

Determination of clay mineralogy in hemipelagic depositional systems has a great potential for the characterization of environmental changes in those systems. However, this potential has been only little exploited in the analysis of sedimentary basins. In this paper this method is applied to the Represa Formation (upper Albian, Prebetic Zone) in the Serra dels Almaens (Jijona, Alicante). There, the unit reaches a remarkable thickness (> 450 m), and is characterized by marl and limestone alternations deposited in the hemipelagic environments of the ancient southiberian continental margin. The bulk mineralogical composition of the samples was analyzed by the method of polycrystalline powder, and the specific mineralogy of clays by means of oriented aggregates in two fractions: coarse (2-20 m) and fine (<2m). Mineralogically, the samples consist of calcite, phyllosilicates, quartz and dolomite.Within the group of phyllosilicates, smectite, illite and kaolinite were identified. These clay minerals reflect significant changes throughout the sedimentary series, allowing the definition of five successive stratigraphic intervals and their interpretation in terms of the evolution of the sedimentary basin.