An integrated approach using plate tectonic analyses and detailed comparative stratigraphy of the North Atlantic has placed new constraints on the Mesozoic to Cenozoic geological history of the Atlantic margin of NW Europe. Key reconstructions from Mesozoic time to the present day have been plotted to show the evolution of the North Atlantic, and in particular the Rockall Trough. The reconstructions show Rockall Plateau attached to Greenland from Late Paleozoic time (380 Ma) to Late Cretaceous time (83 Ma) since when Rockall remained attached to Eurasia. The Rockall Trough probably initiated during end-Carboniferous to Early Permian time and underwent further stretching episodes in the Early Triassic, Early Jurassic, Middle Jurassic, Late Jurassic, Early Cretaceous, mid-Cretaceous and Late Cretaceous to give the present-day Rockall Trough configuration. The Permo-Triassic rift was dominated by oblique opening with a left-lateral component of strike-slip. Jurassic through Early Cretaceous extension was characterized by predominantly left-lateral strike-slip with a minor dip-slip component in the Faeroe basin and north Rockall Trough, and mainly dip-slip extension in central and south Rockall Trough. In Early Cretaceous time (mid-Aptian) the majority of the United Kingdom Continental Shelf (UKCS) Atlantic margin underwent orthogonal opening followed by continued extension in Late Cretaceous to Paleocene time, culminating in the opening of the North Atlantic west Rockall Plateau. The main Late Jurassic and Early Cretaceous rift episodes conveniently divide the stratigraphy into pre-, syn- and post-rift megasequences which form gross play fairways along the North Atlantic margin. Analysis of these fairways permits integration of data from both mature (e.g. North Sea) and immature (e.g. North Atlantic margin) exploration provinces and helps provide a consistent, predictive approach to the assessment of future hydrocarbon potential of the frontier basins lying along the North Atlantic margin.

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A description of the distribution, drainage basin characteristics, surface morphology, depositional process and age of 64 alluvial fan systems from both flanks of the hyper-arid Coastal Cordillera of northern Chile between 22°15′S and 23°40′S is presented. The coastal fans on the western flank of the Coastal Cordillera are dominated by debris-flow deposits fed from steep catchments. Two drainage basin types are recognized: type A drainage basins are small (10–30 km2) and do not cut back beyond the main coastal watershed; and type B drainage basins are large (up to 400 km2) and cut inland beyond the coastal watershed. The western Central Depression fans on the eastern flank of the Coastal Cordillera are characterized by sheetflood deposition fed from relatively shallow catchments in small drainage basins (10–50 km2). The surface morphology, sedimentation rates, a luminescence date and regional cosmogenic radionucleide data suggest that these fans have been inactive for at least the last 230 000 years and probably for much of the Neogene.The principal control on fan activity in the study area is climate. The Coastal Cordillera forms an orographic barrier to recent El Niño-related precipitation events that are restricted to the western flank of the Coastal Cordillera. These events did not penetrate into the Central Depression as indicated by the inactive nature of the western Central Depression fans located 25 km east of the active coastal-fan catchments. This scenario is considered to have prevailed for much of the Neogene. Climate also controls rates of weathering on alluvial-fan surfaces. The coastal fog results in rapid salt weathering of clasts on coastal fans resulting in the production of fines, but does not penetrate into the Central Depression. Fault activity is important in controlling drainage basin size. The larger (type B) drainage basins are commonly focused on active faults that cut the coastal watershed, facilitating drainage basin expansion. Source-area lithology is not important in controlling depositional processes. Fans on both sides of the cordillera have the same basaltic andesite and granodiorite source lithologies, yet coastal fans are dominated by debris-flow and western Central Depression fans by sheetflood deposition. A combination of chemical weathering and stream power related to gradient are considered to account for the differences in process.

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