Cette étude stratigraphique, réalisée dans les bassins tertiaires du sud de la Turquie ouverts sur la Méditerranée, a permis de caractériser les différentes biozones du Tertiaire méditerranéen de l'Éocène inférieur au Pliocène. A l'ouest du bassin d'Anlalya la continuité des dépôts depuis le Crétacé terminal jusqu'au Langhien n'est pas interrompue par des lacunes importantes. Par contre à l'est (Antalya, Mut, Adana) la transgression néogène (Burdigalian à Langhien) est très nette sur les séries tectonisées, la série y est plus complète, comportant les niveaux évaporitiques du Miocène supérieur puis les marnes de Pliocène inférieur. Ces résultats sont complétés par une analyse micropoléontologique de quelques niveaux fossilifères du bassin de Mut où une espèce voisine de Globigerina ciperoensis Bolli (Oligocène) se trouve associée en très grand nombre à une microfaune d'àge burdigalien supérieur à la population observée ici est très similaire à celle de la, Paratéthys mais rend difficile l'utilisation stratigraphique de l'espèce Globigerina ciperoensis dans le domaine méditerranéen.
LOCACE is an interactive system designed to test the geometrical coherence of a depth-converted seismic section. The approach is to restore the geological layers in their initial deposit positions. If this restoration is possible, the hypothesized interpretation may be correct. If the restoration is impossible or unrealistic, the interpretation will be wrong. Basically, the restoration process assumes the layer's surface is conserved during deformation. It can also assume a given surface variation, for instance, when there is compaction due to sediment burying. Different models of deformation can be applied, depending on the geologic context: conservation of both length and thickness (Kink method) for constant-thickness layers, or conservation of length and thickness ratio or conservation of thickness and length ratio for nonuniform sequences. To obtain a meaningful result, a cross section processed with LOCACE must be in the direction of the tectonic displacement. The tectonic style can be extensive or compressive. LOCACE does not provide the correct interpretation, rather it tests the geometric soundness of the geologist hypotheses. Graphical editing allows one to modify the representation of any section during the testing process. The deformation models can be applied backward or forward in time. The balancing of the initial cross sectionmore » implies some geometric modifications. The seismic coherence of this interpretation is checked with a ray-tracing program. This trial-and-error process can be interacted.« less
The Sub Andean Zone of Bolivia is a very prolific exploration zone. During the last ten years, the<br>exploration targets have changed. Numerous oil fields have been discovered in the years 70-90 in the<br>Carboniferous and upper Devonian in the foreland and easternmost emerging anticlines but the exploration get<br>now more active westward with deepest targets in the lower Devonian. The existence of this petroleum system<br>was proven since the discovery of the San Alberto field (San Alberto-X9 in 1990), but the deep prospects in the<br>south SAZ are much targeted only from 10 years. In addition on the cost of the deep wells, moving westward<br>also means steeper anticlines and poor resolution of the seismic images. For the geologists however, the more<br>challenging issues come from the fact that the target is now below an important decollement level, the middle<br>Devonian shale of the Los Monos Fm.
The deformation fronts of the Cyprus arc and the Mediterranean ridge, extending from the Turkey-Syria boundary to north Cyrenacia, are the southernmost superficial expression of the convergence between the Eurasian and African plates. They separate the Eastern Mediterranean deep basin into two different structural units: (1) A thrust belt, northward, with the presence of Cenozoic sedimentary basins which could be considered piggy-back basins (Iskenderun, Adana, Cilicia, and Antalya basins). These basins, filled by 4,000 to 6,000 m of Cenozoic sediments, lie on a substratum composed of south-vergent nappes emplaced between the Late Cretaceous and the late Miocene. (2) A foreland area, southward, where the thick Herodotus and Levantine sedimentary basins, relatively undeformed, lie on the passive and subsident African continental margin initiated during Late Triassic or early Liassic time. Due to the still-active collision between the thrust belt and the Erathosthenes seamount, Cyprus was uplifted and today represents the emerged part of the deformation front. During the Messinian, with the isolation of the Mediterranean Sea, evaporitic deposits including a salt layer (sometimes more than 2,000 m thick) were widely distributed into the Iskenderun, Cilicia, Antalya, Levantine, and Herodotus basins. In these basins, the Messinian sedimentation was directly controlled by basinmore » topography.« less
We present results of a study realized from petroleum data of Yacimientos Petroliferos Fiscales Bolivianos of the most important transfer zone of the Bolivian Andean belt: the Santa Cruz transfer zone. Frontal part of the Bolivian Andean belt consists of a thick series (6 to 8 km) of paleozoic to cenozoic sedimentary rocks thrusted eastwards on a sole thrust located in paleozoic series. The frontal part of the belt, globally N-S oriented, undergoes an important deviation East of Santa Cruz with a left lateral offset of 100 Km. Taking into account the E-W shortening direction, this transfer zone can be interpreted as a lateral ramp. The Santa Cruz transfer zone coincide with a set of small oil and gas fields whereas frontal structures lack hydrocarbon occurrences. We are then faced with a two-fold problem: (1) what is the origin of the transfer zone (2) why are the oil and gas concentrated in the transfer zone Our synthesis shows that the transfer zone is superimposed on the limit of a detached Paleozoic basin whose border direction is oblique to the regional shortening direction. We then interpret the oil and gas formation in two steps: (1) source rock maturation and hydrocarbon migrationmore » towards the top of the Paleozoic sedimentary wedge before Andean deformation. (2) hydrocarbon dismigration towards anticlinal structures developed during the lateral ramp propagation. In order to test our interpretation we performed a set of analog model experiments whose 3D visualization was analyzed by computerized X-ray tomography.« less
