El registro sedimentario de la cueva de bolinkoba (abadiño, bizkaia): Una historia geológica de rellenos y vaciados
- Peru Bilbao Lasa
- Iñaki Yusta
- Arantza Aranburu Artano
- Iñigo S.C. Areitio
ISSN: 2341-3689
Year of publication: 2015
Issue Title: Excavaciones Arqueologicas en Bizkaia
Issue: 6
Pages: 89-102
Type: Article
More publications in: Kobie .Bizkaiko Arkeologi Indusketak = Excavaciones Arqueológicas en Bizkaia
Abstract
The stratigraphical and sedimentological description of the endokarst fillings and the information provided by the granulometric and mineralogical analysis, has allowed to determine the geological evolution of Bolinkoba Cave. Two allostratigraphic units have been described. The first is mainly composed by alochthonous sediments of fluvio-karstic origin. The bottom of the second allostratigraphic unit is characterised by the local presence of a flowstone type speleothem, few small stalagmites and a layer of iron and manganese oxides, which denotethe lack of external sedimentation and dripping of water by infiltration (warm and humid climate). In the overlying levels, the abundance of sandstone pebbles decreases, as the amount of autochthonous limestone clasts increases, due probably to the transition from a relatively wet and humid climate to a colder and drier period.