Erkiaga, M.García Garmilla, FranciscoRioja, M. A.Elorza, Javier2016-06-082016-06-081996http://hdl.handle.net/10272/12262Substantial dolomitization and calcitization processes occurred in upper Turonian-lower Coniacian and upper Maastrichtian-lower Danian carbonates at El Ribero and Quecedo sections, respectively. Carbonate precipitation is in both cases related to first order sequence boundaries. Textures under S.E.M. reveal m o re im p o rta n t processes o f dissolution at El Ribero in comparison to those a t Quecedo, suggesting an aggressive meteoric phreatic zone. C and O isotopic relations tend to become positive just below the unconformities as a result of the influence of marine waters. A general comparison show more heavy isotopic values at Quecedo. A marine/mixing water model of dolomitization is proposed for both dolomites, but with a major influence of marine waters at QuecedospaAtribución-NoComercial-SinDerivadas 3.0 Españahttp://creativecommons.org/licenses/by-nc-nd/3.0/es/Upper CretaceousBasque-Cantabrian BasinSedimentary rupturesDolomitizationCalcitizationS.E.M. ultratexturesC and O isotopic relationsjournal articleopen access