The deep marine Grès d'Annot Formation is one of the best exposed analogues to sand-rich turbidite sub-surface systems. Provenance and reservoir heterogeneities have been investigated through a geochemical study of different areas and facies in this formation. Most compositions may be described as mixtures between carbonate and three clastic end-members, i.e. clay, framework grains and a subset of the heavy minerals (zircon, Tioxide, apatite, monazite). These end-members have a nearly uniform chemistry over the studied area and a granite-dominated provenance consistent with a Corsica-Sardinia source hypothesis. This rather uniform provenance makes the Annot Formation a favourable case for exploring the relationships between facies and geochemistry. Not only do different facies differ in average composition, but chemical variations at the bed scale fingerprint the depositional mechanism: archetypal (graded) turbidites and traction-dominated (over-bank) deposits display contrasting variation trends in geochemical plots. The local-scale variation patterns and the general relationship between grain size and chemistry are tentatively integrated in a single differentiation model, providing a rationale for the use of geochemistry in provenance studies, and a possible way to characterize sedimentary facies.
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Deep-Water Sedimentation in the Alpine Basin of SE France: New perspectives on the Grès d'Annot and related systems
The Grès d′Annot Formation of SE France constitutes a classic and outstanding example of a sand-rich turbidite system controlled by synsedimentary tectonics, and has often been used as an outcrop analogue for deep-water hydrocarbon reservoirs. Over the last 10 years, research efforts by different academic and industrial teams have led to important reappraisals of prevailing ideas on the Gres d′Annot, particularly on the nature and controlling factors of the depositional processes, the small-scale architecture and sequence organization of the deposits, the tectonic regime of the basin and its impact on palaeogeography, and the interaction between sediment gravity flows and basin-floor topography.
This volume offers a multidisciplinary overview and draws up the ′state-of-the-art′ of scientific knowledge on this influential turbidite system. Complementary aspects are covered, from structural geology, sedimentology and sequence stratigraphy, to modelling of sedimentary processes and architectures, geochemistry, reservoir characterization, seismic modelling and uses as analogues for deep-marine hydrocarbon fields.
This book will be of use to both academic researchers (geologists and geophysicists) and industry professionals dealing with the characterization and modelling of deep-water sediments.