Succession of rudistid lithosomes along the western coastal margin of the Iberian Basin (Coniacian, Castrojimeno Section, central Spain)

Abstract

Rudistid lithosomes cropping out near Castrojimeno, at the northern margin of the Central System in north-central Spain, provide detailed information on their composition and structure, on their development and succession, and about their relationship with the Coniacian sequence stratigraphy framework of the Iberian Basin. Most rudist assemblages are oligospeciWc, with a dominant species, or monospeciWc. The radiolitids Biradiolites angulosus, Praeradiolites requieni, and Radiolites sauvagesi and the hippuritids Hippurites incisus and Vaccinites giganteus were identiWed. Radiolitids demonstrate wide intraspeciWc morphological variability. The following Riding's structural categories of organic reefs are represented: segment reefs, spaced and close cluster reefs, and close cluster/frame reefs. Bioclastic beds of reworked rudist fragments occur below or in between the rudist reefs. The vertical succession of all Wve types of rudistid lithosomes distinguished evidences a shallowing-upward trend. Rudistid lithosomes developed on the coastal margin during the superposition of the highstand sea-level stage of third-and fourth-order depositional sequences.

Revision and new data on the Coniacian ammonite genus Hemitissotia in the Iberian Peninsula (Spain and Portugal)

“…Studies on the cephalopod assemblages of the late Cenomanian-early Turonian episode in these regions have been undertaken recently (Callapez 1998(Callapez , 2003Callapez and Soares 2001;Barroso-Barcenilla 2006, 2007Barroso-Barcenilla and Goy 2007. In contrast, the palaeoenvironments along the Iberian Peninsula of the late Coniacian-early Santonian episode are less well understood, and previous interest has mainly focused on rudist assemblages and facies of shallow carbonate platforms (Gil et al 2009).…”