Geoquímica microestructural en Praeradiolites ciryi (Hippuritacea, Bivalvia, Cretácico Superior de Gredilla de Sedano, Norte de Burgos, España).
- Regidor-Higuera, I. 1
- García-Garmilla, F. 1
- Zuluaga, M.C. 1
- Elorza, J. 1
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1
Universidad del País Vasco/Euskal Herriko Unibertsitatea
info
Universidad del País Vasco/Euskal Herriko Unibertsitatea
Lejona, España
ISSN: 0213-683X
Argitalpen urtea: 2003
Zenbakia: 34
Orrialdeak: 183-186
Mota: Artikulua
Beste argitalpen batzuk: Geogaceta
Garapen Iraunkorreko Helburuak
Laburpena
The detailed geochemical evolution along two transects of the shell of one specimen of Praeradiolites ciryi is examined along annual, seasonal and fortnightly («doublet») sclerochronological records. The analyzed specimen is thought to have suffereda low diagenetic degree because it mostly retainsthe original composition of both cellular and compact microstructuresof the shell. So it can be deduced from the «saw-tooth» geochemical profiles, the Mg-Sr high mmol/mol values, the Mn-Fe low mmol/mol values and the unequal, distribution of luminescence that accurately follows shell microstructural features. The organic control upon the geochemistry of the shell is still observable because two zones, each one having a characteristic cationic trend, can be distinguished within a «doublet»; This fact is reinforced by changes in the luminescence indicating some periodic phenomenon of fortnightly cyclicity. The decrease in cationic content and increase in organic matter content towards the upper half of the «doublets» could be related to metabolic activity changes preparatory for the construction of a new growth line.