Abstract Assemblages of planktic and benthic foraminifers were studied from the northern continental margin of the Late Cretaceous Iberian Plate (Basco-Cantabrian Basin, BCB). A cross section from inner-ramp carbonates containing large benthic foraminifers (section Sobrón) to hemipelagic marl–limestone alternations (Villasana section) and pelagic claystones and marlstones (Galarreta–Gordoa section and Urbasa-2 borehole) allows the study of foraminiferal parameters. These parameters are plankton/benthos ratio (p/b ratio), foraminiferal number, species richness, abundances of agglutinated and calcareous benthic foraminifers, heterogeneity, keeled and non-keeled (globular) planktic foraminiferal morphogroups, and biofacies distribution of benthic foraminifers. Foraminiferal parameters are studied with respect to relative sea-level changes in the Cenomanian–Turonian. Ratios of planktic to benthic foraminifers and abundances of benthic foraminifers match long-term (4–8 Myr) sea-level changes in the BCB. Foraminiferal numbers and p/b ratios are highest at maximum flooding surfaces and low at sequence boundaries. Abundances of calcareous benthic foraminifers can increase during prograding highstand systems tracts. Abundances of agglutinated benthic foramini-fers increase during prograding lowstand systems tracts and are lowest during maximum transgression. Species richness is often highest in transgressive systems tracts. Keeled planktic foraminiferal morphogroups are concentrated in the highstand systems tract and at the maximum flooding surfaces in outer-shelf depositional realms. However, there is no unique solution for a sequence stratigraphic interpretation from foraminiferal parameters alone. Often, there is more than one candidate for the interpretation of a sequence stratigraphic surface from p/b ratio or foraminiferal numbers. These results were compared to the analysis of foraminiferal biofacies from the Escalles section (Paris Basin, northern France). The cyclic hemipelagic marls and gray chalks are composed mainly of coccoliths, foraminifers, and calcareous dinoflagellate cysts. Parameters like the p/b ratio did not match existing sequence stratigraphic interpretations. Instead, it can be shown that the precession-controlled cyclicity is explained by a paleoceanographic model. This model proposes stratified water masses during deposition of marls and mixed high-productivity water masses during deposition of chalks. Sea-level changes are indicated by (1) the foraminiferal number, (2) the total abundance of planktic foraminifers, and (3) by the abundance of Pithonella ovalis , which all increase with transgressive systems tracts and decrease in highstand systems tracts. Four curves with p/b ratios from logged sections in the BCB and in the Paris Basin and from one borehole in the BCB were converted to time series and then stacked together. This stacked p/b ratio curve was converted by paleoslope modeling in the BCB to a proxy for sea-level change in Cenomanian to Turonian times. Three periods of sea-level rise in the Cenomanian are recognized on this proxy (97.5 Ma, 95.2 Ma, 93.8 Ma). In the Turonian, two major sea-level rises are identified (91.2 Ma, 90.1 Ma) together with two major sea-level falls (around 92 Ma, 89.5 Ma). This proxy predicts no major sea-level falls in the Cenomanian. Instead, the proxy sea-level rises from datum plane at the Albian–Cenomanian boundary to + 30 m (minimum estimate)/+ 50 m (maximum estimate) in the Early Turonian. The sea-level proxy has a value of +10 m above the datum plane at the Turonian–Coniacian boundary. Positive excursions of stable carbon isotope data match strong sea-level rises or falls in the Middle Cenomanian, the Late Cenomanian, the Middle Turonian, and the Late Turonian, but not in the Early Cenomanian.

Abstract During the Late Cretaceous the northeastern margin of the Arabian plate (Zagros–Fars Area) was characterized by significant variations in sedimentary facies, sedimentation patterns and accommodation space, and by shifting depocentres. A succession of events recording the evolution of the region from a passive to an active margin is documented by the study of eight outcrop sections and one well. This new study uses new age dating (benthic and planktonic foraminifers, nannoplankton and radiolarian biozonations and strontium isotope stratigraphy). The new observations provide a detailed overview of the response of the sedimentary system to changes in the tectonic regime related to obduction processes. These changes are very well shown in regional cross-sections and palaeogeographical maps. Three tectono-sedimentary phases are recognized indicating the evolution from a passive to an active margin: Phase I (Late Albian to Cenomanian, before obduction) comprises three depositional third-order sequences comparable with those of the other parts of the Zagros and Arabian plate. This interval is composed of shallow-water platform carbonates and intra-shelf basins. The platform facies consists of rudist and benthic foraminifer-dominated assemblages, whereas the intra-shelf basins contain an ‘ Oligostegina ’ facies. Eustatic sea-level variations and local differential subsidence controlled sediment deposition during this phase. Phase II (Turonian to Late Campanian, obduction phase) is characterized by major changes in depositional environments and sedimentary facies, as a result of obduction and foreland basin creation. It consists of pelagic and platform carbonates in the south, and a foreland basin with obducted radiolarites, ophiolitic and olistoliths or thrust slices in the north. During this phase, large volumes of turbidites and gravity flows with olistoliths were shed from both the SW and NE into the foreland basin. The age of the tectonic slices increases upward through the section, from Early Cretaceous at the base to Permian at the top. Based on various dating methods used on the far-travelled sediments, the depositional age of the radiolarites can be attributed to the Albian–Cenomanian, whereas the planktonic foraminifers are of Santonian to Campanian age. Phase III (Late Campanian to Maastrichtian, after obduction) shows the development of rudist-dominated carbonates in the NE prograding onto the deep basinal facies in the centre of study area. In the extreme NE no sediments of this age have been recorded, suggesting uplift at that time.

In this section, only the stratigraphy of the rocks deposited before and during the violent events of the Cuban orogeny will be described. The deformation probably reached its peak during the early–middle Eocene. The reason for this rather indefinite time assignment is that no index faunas have been found to separate the middle from the lower Eocene in the syn-orogenic flysch sediments, much less in the wildflysch that characterizes the culmination of the orogeny. The only evidence that the orogeny is pre–upper Eocene is a widespread, well-defined unconformity below an upper Eocene orbitoid-rich limestone that, although occasionally deformed, was not involved in the strong orogenic tectonism. As will be seen later, the tectonic events that marked the end of the orogeny were not exactly synchronous all over Cuba. In the south, the orogenic deformation started in the late Maastrichtian to Paleocene, whereas in the north, the deformation started in the early Eocene. The molasse (or erosion of already inactive topography) cycle startedinthe southinthe early Eocene while thrusting proceeded in the north in the middle Eocene with the production of associated flysch deposits (or erosion of an active orogenic front). The mo-lasse was carried piggyback by the northward advancing thrusts while contemporaneous flysch was being generated in the north. Stratigraphy and structure are intimately intertwined in Cuba; the significance of structural features can be understood only through the knowledge of stratigraphy. Therefore, in this chapter, the stratigraphy will be described first to establish a plausible preorogenic paleogeography.As previously mentioned, many