Paleoclima y diagénesis en las calizas rojas de Ereño (Bizkaia)

• Autores: Laura Damas Mollá
• Localización: Geogaceta, ISSN 0213-683X, Nº. 47, 2009, págs. 61-64
• Idioma: español
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• Resumen

  • Carbon and Oxygen isotopic values measured on rudist and Chondrodonta sp. shells from the red urgonian limestones of Ereno (Upper Aptian-Lower Albian, Bizkaia) have been demonstrated to be a very useful tool for reconstruction of both palaeoenvironmental features and diagenetic conditions that affected the famous ornamental stone. The �Â18O�ñ (PDB) values obtained from rudist recrystallized hipostraca suggest an influence of increasing diagenetic temperatures rather than the action of meteoric waters during early diagenetic stages. On the other hand, the �Â18O�ñ (PDB) values from diagenetically less-affected shells (Chondrodonta sp.) and parts of the shells (rudist miostraca) reveal palaeotemperatures of 19-27oC very close to those of coetaneous marine waters and compatible with the seasonal variations described for a 30oN palaeolatitude in the Tethys domain. Palaeoesalinities in the marine waters of the Ereno platform could oscillate between 32-36�ñ, slightly above the normal values recorded at present.