<p>Submarine fans are deposits of coarse sediments of continental origin in the deep sea, and are generally characterized by a complex depositional architecture, due to the multiple triggering mechanisms of deep-water sediment gravity flows. Consequently, this poses great challenges to deep water petroleum exploration and development. We analyzed the geomorphologic evolution and architecture of Campanian, deeply buried, submarine fans in the Kribi-Campo sub-basin, offshore Cameroon. Using a 3D seismic reflection data set and logs from two wells, we mapped seven horizons, including the fan base, fan top and five internal horizons. In cross-section, the fan is characterized by<strong> </strong>a high amplitude seismic facies exhibiting an aggradational pattern with parallel and continuous reflectors. The stacked fan-shaped morphology is up to 340 ms TWT thick, extends over an area of 600 km<sup>2</sup> and oriented NE-SW, near the Kribi High. The analysis of lobes and channels on each horizon provided a timelapse that captures the major geomorphologic transformations of the submarine fan from its initiation, growth, and abandonment.  The submarine fan is composed of depositional lobes whose beds consist of sand, silt and mud. The detailed structure of these lobes has a finger-like morphology and is generally oriented at high angles to the channel that delivered the sediment to the lobes. The finger-like features are interpreted as thick massive sands, formed as a result of sediment-gravity flows which branched off the main flow eroding into pelagic clay substrate. Two types of channel morphology were identified (straight and sinuous). Our results show that channel and sand-body architecture evolve in a predictive manner, primarily controlled by fan aggradation. The elongated shape and morphology of the submarine fan may arise from the interaction of the fault-related folds and Kribi High, with sandstone deposition within the intervening topographic lows, sourced from the east. The 3D seismic geomorphological analysis of the submarine fan, as presented in this study, is essential to better understand their geometries, facies distribution, stacking patterns and depositional architecture to improve reservoir predictions.</p>

<p>The Babouri-Figuil Basin is located in the northern part of Cameroon and is part of the Bénoué trough. One of the most remarkable features of this basin is the presence of carbonate concretions commonly called septaria. However, the understanding of nature of these concretions remains limited. In the first phase of this study a detailed field work was carried in the basin. The Babouri-Figuil Basin has four lithofacies encompassing limestones, marlstones, sandstones and conglomerates. Its depositional environment is fluvial to fluviolacustrine. These facies are organized in asymmetrical synclines and crossed by basaltic intrusions. The concretions identified occurs in the marly facies. Numerous descriptive criteria noted in the field made it possible to give their size, their context of establishment, as well as the factors which control the forms of these septarias. These septarias are greyish or dark brown and massive in structure. Their size varies from 15-57.5 cm with circumferences ranging from 23-87cm. They also have intersection cracks due to their maturity or aging. These intersection of septarian cracks are filled and indicate different generations. Ovoid, rounded, disc, elongated and chocolate bar morphologies have been observed in the study area. These shapes are controlled by the thickness and shape of the marls. Thus, where the thickness is important, the septarias are well developed and generally take ovoid, rounded or spherical shapes because the marl has weak planes. On the other hand, when the thickness of the marl is thin or in lens, the septarias tends to follow only the space and the shape that the marl occupies and, tending to make it disappear, thus creating elongated, flattened and even rounded shapes. Consequently, the septarias of the Babouri-Figuil Basin is post-sedimentary to the marl deposits.</p>

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