Pdf: http://www.ulb.ac.be/science....9at.pdf

Two thin condensed sections of Rosso Ammonitico from Southern Spain are compared to similar facies in Northern Italy. The characteristic microfauna is composed of protoglobigerinids, Calcisphaerulidae associated with Bositra and abundant young ammonites. The matrix is diagenetically altered and no iron bacterial filaments are observed. The iron has been remobilized in the early stages of the lithification as shown by the microsparitization of the matrix, the strong solution-recrystallization processes inside the shells and the fillings of the complex calcitic veinlets associated with the formation of very irregular hematitic veils that criss-cross the matrix. In such strongly diagenetically altered environments submicronic filaments would have been destroyed.