Formación de alvéolos sobre basaltos y areniscas en la zona costera de Meñakoz (Sopelana, Bizkaia): controles litológicos y ambientales

[EN] In the coastal area of Meñakoz (Sopelana, Bizkaia) outcrop, in mechanical contact, alkaline basalt lavas (upper Albian) and turbidite sandstones of the black flysch (upper Albian-lower Cenomanian) are affected by an intense weathering process. The alveoli formed, in both lithologies, present a...

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Bibliographic Details
Authors: Elorza, José Javier, Aparicio, Alfredo
Format: article
Status:Published version
Publication Date:2015
Country:España
Institution:Consejo Superior de Investigaciones Científicas (CSIC)
Repository:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/126917
Online Access:http://hdl.handle.net/10261/126917
Access Level:Open access
Keyword:Active weathering
Alveoli
Basalts
Sandstones
Biscay
Meteorización activa
Alvéolos
Basaltos
Areniscas
Bizkaia
Description
Summary:[EN] In the coastal area of Meñakoz (Sopelana, Bizkaia) outcrop, in mechanical contact, alkaline basalt lavas (upper Albian) and turbidite sandstones of the black flysch (upper Albian-lower Cenomanian) are affected by an intense weathering process. The alveoli formed, in both lithologies, present a typology conditioned by: a) the mineralogical composition (basalts vs. sandstones); b) fabric (massive vs. cross/convoluted lamination); c) the coastal environment in a humid-temperate climate, leading to repeated wetting-drying cycles; d) the different orientation of the surfaces to the prevailing wind; e) biogenic activity (algae and lichens), as a temporary protective surface. The weathering process is in an advanced stage of degradation with destruction and coalescence of cells, although there are also sets of cells preserved in good condition. It discusses the main internal/external factors that have enabled, accelerated and blocked its development, with strong variations in the speed of the process.