Transfer zones form important structural elements in extensional basins, accommodating displacement changes between individual fault and basin segments. Transfer zone geometry is related to the extension direction and the displacement, dip polarity, overlap and overstep of fault/basin segments adjacent to the zone. Topographic changes associated with transfer zones have a direct influence on drainage basin evolution, sediment transport and stratigraphy. Two main categories of transfer zone can be identified: (i) interbasin transfer zones, linking individual half graben, and (ii) intrabasin transfer zones, linking individual fault segments within a half graben. Interbasin transfer zones range from interbasin ridges to broad faulted highs and major relay ramps. They have a marked influence on basin stratigraphy and drainage evolution, often separating half graben with distinct stratigraphies and acting as conduits through which major axial depositional systems enter the rift zone. Intrabasin transfer zones range from relay ramps separating adjacent en echelon normal faults to discrete fault jogs. Intrabasin transfer zones commonly act as a conduit for local sediment transport, but have minimal effect on basin-scale stratigraphy. Transfer zones also affect early post-rift sedimentation and are important elements in controlling fluid migration in the subsurface.

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The relationship between the northern part of the Caledonian fold belt of East Greenland and the North Greenland fold belt is explored within the context of Silurian sedimentation and tectonics. A model is developed relating the Caledonian nappes of eastern North Greenland to major tectonic and sedimentological features of the Silurian of the remainder of North Greenland. The abrupt change from a thin succession of predominantly slowly deposited muds to a thick succession of rapidly deposited sandstone turbidites at the Ordovician/Silurian boundary, in the deep-water basin N of the carbonate platform in North Greenland, is directly related to uplift and westerly directed nappe emplacement in the eastern Caledonides. It is suggested that uplift to the E of North Greenland, which commenced in the late Ordovician or early Silurian, provided the main source of the Silurian turbidites of North Greenland. This is corroborated by the dominant westerly transport direction of the Silurian turbidites. Nappe emplacement during the latest Llandovery (Silurian), and foundering of the whole of the carbonate platform of eastern North Greenland E of the Victoria Fjord Arch (approximately 60 000 km 2 ), is marked by the replacement of shallow water carbonates by basin turbidites. These events were directly related to isostatic readjustments as the nappes advanced onto the eastern fringe of the platform.

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