Evidencias de hidrotermalismo diagenético en la formación Oiartzun (Cretácico Superior), margen NE de la Cuenca Vasco-Cantábrica

  1. M. Ladron de Guevara 1
  2. A. Bodego 1
  3. A. Aranburu 1
  4. L. Damas-Mollá 1
  5. E. Iriarte 2
  1. 1 Universidad del País Vasco/Euskal Herriko Unibertsitatea

    Universidad del País Vasco/Euskal Herriko Unibertsitatea

    Lejona, España

    ROR https://ror.org/000xsnr85

  2. 2 Universidad de Burgos

    Universidad de Burgos

    Burgos, España

    ROR https://ror.org/049da5t36

Geotemas (Madrid)

ISSN: 1576-5172

Year of publication: 2021

Issue Title: X Congreso Geológico de España

Issue: 18

Pages: 160

Type: Article

More publications in: Geotemas (Madrid)


The upper Albian-lower Cenomanian braidplain delta system of the Oiartzun Formation expands alongside the NW Bortziriak Massif border (NE margin of the Basque Cantabrian Basin). Shallow marine carbonate patches are embedded between terri- genous delta-front sediments, probably linked to the halokinetic forced-fold anticlines developed during that time (Bodego et al, 2018a), which show altered diagenetic products. The objective of this study is to characterize and interpret the processes responsible for such diagenetic modifications from the Oiartzun Fm. in Txoritokieta area (Donostia). Diagenetic processes and their evolution have been defined based on cross-cutting relationships from both field outcrop and thin section observa- tions (petrological study through staining, cathodoluminescence and SEM), as well as geochemistry and structural analysis. Pigmentary iron inflow, recrystallization/neomorphism of the micritic matrix, several fracture systems and either dolomite precipitation or mineral replacement (siliceous and carbonaceous), are some features resulting from possible hydrothermal activity in relation to extensive tectonic episodes (Bodego et al, 2018b).