Stratigraphie sequentielle de l'Aptien du sous-bas
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摘要

A correlation is established in a north-south transect based on continuous outcrops. Considering the different reference surfaces and the geometry, three major depositional sequences can be distinguished which can be subdivided into a complex arrangement of parasequences. These third-order sequences are composed of a lower retrogradational and an upper progradational trends. The first sequence contains orbitolinid bioaccumulations in the retrogradational trend and oolitic-bioclastic shoals in the progradational trend. The second sequence exhibits, from bottom to top, a transgressive, a regressive and a forced-regressive trends. Ammonite-rich marls characterise the transgressive trend, whereas bioconstructions rich in coral-chaetetids-microbialites are abundant in both regressive and forced-regressive trends. The maximum flooding of this sequence is widely distributed across the whole Iberian platform. Finally, the third sequence shows the installation of homogeneous rudistid bioaccumulations in a retrogradational and a progradational trends. Each major sequence boundary marks a community replacement, whose respective fossil associations are dominated by (1) orbitolinids, (2) corals-microbialites, (3) corals-chaetetids-microbialites, and (4) rudists.

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