[1] Seismic reflection profile data are used to determine the stratigraphic ''architecture'' of the flexural moat that flanks the Cape Verde Islands. The moat region is characterized by upward of 1-2 km of poorly to well-stratified material. The two lowermost units thicken from west to east and are attributed to sediment loading and flexure at the nearby West Africa continental margin during Early Cretaceous to early Miocene. The two uppermost units, in contrast, thicken concentrically around the islands and are attributed to the infilling of a flexural moat that formed by volcanic loading since the early Miocene. Flexure modeling shows that the thickness of the moat infill cannot be explained only by surface loading and requires that the downward flexure due to surface loads is opposed by an upward acting subsurface load. The best fit combined surface and buried loading model is for an elastic thickness, T e , of 29 km, a load and infill density of 2700 kg m À3 , and a ratio of surface to subsurface loads, f, of 0.2. These results are in accord with spectral studies of free-air gravity anomaly and topography data based on the admittance technique. The subsurface loads are spatially limited to the islands and their submarine flanks. Nevertheless, they are associated with a broad regional uplift of up to $400 m. The uplift is large enough to explain why the moat infill is generally tilted away from, rather than toward, the islands. The uplift is too small, however, to account for the height of the swell, upon which the Cape Verde Islands are superimposed. The origin of the Cape Verde swell is not known. However, a normal T e and a modest heat flow anomaly suggest that the swell cannot be fully explained by uplift due to thermal reheating of the lithosphere by an underlying ''hot spot'' and that other, deep-seated, mantle processes must be involved.

[1] We have used biostratigraphic data from deep exploration wells to determine the tectonic subsidence history of the Somaliland (northwestern Somalia)-Yemen conjugate margin, a poorly known margin in the central part of the Gulf of Aden. Bathymetry and magnetic anomaly data suggest the Gulf of Aden is a young feature that formed following the rifting apart and breakup of the African and Arabian plates~32 Ma. Our tectonic subsidence data suggest, however, that the present-day Gulf of Aden developed on an earlier Mesozoic rift system. The oldest episode of rifting initiated at~156 Ma and lasted for~10 Ma and had a NW-SE trend. We interpret the rift as a late stage event associated with the breakup of Gondwana and the separation of Africa and Madagascar. At~80 Ma, there is evidence of an intermediate rift event which correlates with a rapid increase in spreading rate on the ridges separating the African and Indian and African and Antarctica plates and a contemporaneous slowing down of Africa's plate motion. The combined effect of all three rifting events has been to thin the crust and upper mantle by up to a factor of 2. The amount of thinning deduced from the wells is in accord with the crustal structure inferred from available seismic refraction data and process-oriented gravity and flexure modeling. The margin is asymmetric with a steeper gradient in the Moho on the Yemen side than the Somaliland side. The main discrepancy is on the Yemen side where the gravity-derived Moho is 10 km deeper than the well-derived Moho. We attribute the discrepancy to the addition of material at the base of the crust since rifting, possibly magma sourced from the Afar plume.Citation: Ali, M. Y., and A. B. Watts (2013), Subsidence history, crustal structure, and evolution of the SomalilandYemen conjugate margin,

The Guban Basin is a NW-SE trending Mesozoic-Tertiary rift basin located in northern Somaliland (NW Somalia) at the southern coast of the Gulf of Aden. Only seven exploration wells have been drilled in the basin, making it one of the least explored basins in the Horn of Africa --southern Arabia region. Most of these wells encountered source, reservoir and seal rocks. However, the wells were based on poorly understood subsurface geology and were located in complex structural areas.The Guban Basin is composed of a series of on-and offshore sub-basins which cover areas of 100s to 1000s of sq. km and which contain more than 3000 m of sedimentary section. Seismic, gravity, well, outcrop and geochemical data are used in this study to investigate the petroleum systems in the basin. The basin contains mature source rocks with adequate levels of organic carbon together with a variety of reservoir rocks. The principal exploration play is the Mesozoic petroleum system with mature source rocks (Upper Jurassic Gahodleh and Daghani shales) and reservoirs of Upper Jurassic to Miocene age. Maturity data suggest that maximum maturity was achieved prior to Oligocene rift-associated uplift and unroofing. Renewed charge may have commenced during post-Oligocene-Miocene rifting as a result of the increased heat flows and the increased depth of burial of the Upper Jurassic source rocks in localised depocentres. The syn-rift Oligocene-Miocene acts as a secondary objective owing to its low maturity except possibly in localised offshore sub-basins. Seals include various shale intervals some of which are also source rocks, and the Lower Eocene evaporites of the Taleh Anhydrite constitute an effective regional seal. Traps are provided by drag and rollover anticlines associated with tilted fault blocks. However, basaltic volcanism and trap breaching as a consequence of the Afar plume and Oligocene-Miocene rifting of the Gulf of Aden cause considerable exploration risk in the Guban Basin.

The drive for small and compact electronic components with higher processing capabilities is limited by their ability to dissipate the associated heat generated during operations, and hence, more advanced heat sink designs are required. Recently, the emergence of additive manufacturing techniques facilitated the fabrication of complex structures and overcame the limitation of traditional techniques such as milling, drilling, and casting. Therefore, complex heat sink designs are now easily realizable. In this study, we propose a design procedure for mathematically realizable architected heat sinks and investigate their performance using the computational fluid dynamics (CFD) approach. The proposed heat sinks are mathematically designed with topologies based on triply periodic minimal surfaces (TPMSs). Three-dimensional CFD models are developed using the starccm+ platform for uniform heat sinks and topologically graded heat sinks to study the heat transfer performance in forced convection domains. The overall heat transfer coefficient, surface temperature, and pressure drop versus the input heat sources as well as the Reynolds number are used to evaluate the heat sink performance. Moreover, temperature contours and velocity streamlines were examined to analyze the fluid flow behavior within the heat sinks. Results showed that the tortuosity and channel complexity of the Diamond solid-networks heat sink result in a 32% increase in convective heat transfer coefficient compared with the Gyroid solid-network heat sink which has the comparable surface area under the examined flow conditions. This increase is at the expense of increased pressure drops which increases by the same percentage. In addition, it was found that expanding channel size along flow direction using the porosity grading approach results in significant pressure drop (27.6%), while the corresponding drop in convective heat transfer is less significant (15.7%). These results show the importance of employing functional grading in the design of heat sinks. Also, the manufacturability of the proposed designs was assessed using computerized tomography (CT) scan and scanning electron microscopy (SEM) imaging performed on metallic samples fabricated using powder bed fusion techniques. A visible number of internal manufacturing defects can affect the performance of the proposed heat sinks.

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