RT Journal Article
T1 Alteración diagenética en conchas de rudistas caprínidos del Cretácico Medio de Urdax (Navarra)
T1 Diagenetic alteration in caprinid rudist shells from the Middle Cretaceous of Urdax (Navarra)
A1 Damas Mollá, Laura
A1 Aranburu Artano, Arantza
A1 García Garmilla, Francisco
AB The caprinid rudist shells of the middle Aptian-lower Cenomanian limestones of Urdax (Navarra) havebeen studied for evaluation of the diagenetic degree that suffered from. Strongly recrystallized, the shellsonly preserve the pallial canals and show sparry calcite of different crystal sizes depending on hipostracumor miostracum layers. A later recrystallization produced a clear increase of Mn+2 and Fe+2 content in nondisplaciveveins filled by coarse undulose calcite. The very low Sr+2 /Ca+2 and Na+ /Ca+2 values suggest ahigh diagenetic degree, although their geochemical profiles in «saw-teeth» still remember to us about acertain vital effect. The Fe+2/Ca+2 and Mn+2 /Ca+2 values sharply increase in late-recrystallized zones andveins having strong yellow CL colors. Finally, the Sr+2/Mg+2 values are close to those of abiotic calcite, andthe Sr+2/Mn+2 values do not coincide with those for extant bivalve shells. In all case, the fact that theoriginal microstructure and composition of caprinid shells could make them more particularly propitiousfor diagenetic alteration than specimens of other families like radiolitids should not be discarded
PB Sociedad Geológica de España
YR 2004
FD 2004
LK http://hdl.handle.net/10272/8812
UL http://hdl.handle.net/10272/8812
LA spa
DS Repositorio Institucional de la Universidad de Huelva
RD 1 jun 2026