Diagénesis en las conchas de inocerámidos de la Isla de Castro (Coniaciense final-Santoniense inferior, Cuenca Vasco-Cantábrica): evidencias petrológicas e isotópicas

Pétrographie and isotopic (á!80 and a13C) analyses have been carried out on inoceramid shells from shallow-marine limestone-marl couplets at the Castro Island section (latest Coniacian-lower Santonian, Basque-Cantabrian Basin), in order to determine their diagenetic alteration. Results show that the...

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Bibliographic Details
Authors: Jiménez Berrocoso, A., Elorza, Javier
Format: article
Publication Date:2002
Country:España
Institution:Universidad de Huelva (UHU)
Repository:Arias Montano. Repositorio Institucional de la Universidad de Huelva
Language:Spanish
OAI Identifier:oai:ariasmontano.uhu.es:10272/9985
Online Access:http://hdl.handle.net/10272/9985
Access Level:Open access
Keyword:Inoceramids
Stable isotopes
Cathodoluminescence
Silicification
Coniacian-Santonian
Basque-Cantabrian Basin
Description
Summary:Pétrographie and isotopic (á!80 and a13C) analyses have been carried out on inoceramid shells from shallow-marine limestone-marl couplets at the Castro Island section (latest Coniacian-lower Santonian, Basque-Cantabrian Basin), in order to determine their diagenetic alteration. Results show that the prismatic microstructure of the shells was mainly affected by silica replacement during diagenesis, but very little compaction, cementation and recrystallization occurred. However, these changes do not seem to have modified largely the isotopic composition of the inoceramids, as supported by the low luminescence intensity that show all the shells. In addition, à780 and al3C mean values from inoceramids included in limestones are heavier than those from inocermids in marls, which confirms that the isotopic values were influenced by a paleoceanographic circulation model with estuarine and anti-estuarine regimens