Abstract The Upper Jurassic Hareelv Formation in Jameson Land, East Greenland is one of the world’s finest outcrop examples of a giant sand-injection complex. The contrast between the black, organic-rich hemipelagic mudstones and the injected light yellow sandstones is striking and allows easy recognition of geometries both in close-up and from a distance. The formation is 200–400 m (660–1310 ft) thick, and in the lower part (Katedralen Member), the sandstone/mudstone ratio is roughly 1:1, increasing to about 9:1 in the upper part (Sjsllandselv Member). All sands in the upper Oxfordian–Volgian Katedralen Member have undergone postburial remobilization and injection into the surrounding mudstones, and virtually all primary sedimentary structures have been obliterated. It is thus not possible to provide detailed interpretations of the primary depositional processes. On the basis of sand-body geometry and comparison with the undisturbed underlying Olympen and overlying Raukelv formations, the depositional system is interpreted as comprising slope gullies and laterally extensive base-of-slope lobes. The sandstones occur as thick, virtually structureless bodies, which may be laterally extensive or form mounded or pod-shaped masses. Smaller dikes and sills are ubiquitous, and their geometries range from orthogonal or polygonal to extremely irregular, reflecting injection into mudstones with various degrees of consolidation. Mudstone slabs and fragments of all sizes occur in the sandstones and may easily be mistaken for clasts transported in concentrated gravity flows. They are formed, however, by excavation and rip-down of the mudstone during forceful injection of fluidized sand. Vertical or lateral organizational trends of sandstone bodies are not observed, and no clear indications exist if intrusion of dikes and sills were upward, downward, or lateral with respect to the larger sandstone bodies. The mudstones above large convex- upward sandstone bodies seem, however, to be relatively undisturbed by dikes and sills. Close inspection of some thick, laterally extensive sandstone bodies show that they contain subhorizontal mudstone leaves or layers, indicating long-distance lateral injection and splitting of the injected mudstone package. The thick convex-upward sandstone bodies were, however, clearly intruded vertically upward into the mudstones. No evidence is present for sand extrusion on the sea floor, and remobilization and injection clearly were postburial, probably under a cover of tens to perhaps hundreds of meters. Several generations of injection can be demonstrated based on crosscutting relationships of dikes and sills and the presence of both straight and strongly ptygmatically folded dikes at the same levels. Similar injections are unknown from both older and younger formations in Jameson Land. The Hareelv Formation was deposited during the climax of the most important Mesozoic rift event in East Greenland, and the pervasive remobilization of all sands in the formation is interpreted as caused mainly by cyclic loading triggered by seismic shocks. Additional factors may have included slope shear stress, buildup of pore pressure caused by sediment loading, upward movement of pore waters expelled from the compacting muds, and possibly biogenic and thermogenic gas. The well-exposed Hareelv Formation is an excellent analog for subsurface hydrocarbon reservoirs, which have been modified by remobilization and injection of sands. It provides one of the best field examples known, illustrating the degree to which a sediment can be altered and all primary features destroyed by remobilization, fluidization, and injection.

Abstract The Grès d'Annot onlap on the outer basin margin has been extensively studied, but a number of important issues and critical outcrops remain controversial. A new geological map of the Annot syncline is here presented, supplemented with structural and sedimentological field observations. The mapped onlap traces in Annot reveal a curved, east-concave surface, with distinct westward shift of the successive onlap lines. The inferred onlap direction at Chalufy is to the SW, the only orientation compatible with the movement of the normal fault near Cabane des Abeurons. The similarity of the onlap relations between the areas of Annot and Chalufy, together with the structural features of the Annot syncline, support the concept of a common outer basin margin, rather than of a northern confinement of the Annot turbidites. The margin-onlap setting involved a specific style of syndepositional deformation. As a large, high-density turbidity current arrived on the basin-flank slope, it rapidly decelerated, thickened and dropped its coarse load, while being simultaneously deflected away from the slope. The associated normal stress and overpressure caused sub-horizontal injection and de-lamination of the soft substrate, with the tangential strain curling up the detached substrate slice into an overturned synclinal structure. The process provides an efficient way to incorporate fragments of mudstone and thin-bedded sandstone within the still moving highly-concentrated flow, eventually constituting the chaotic intervals within ‘tri-partite’ beds as the examples observed at the Braux section.

Abstract The Svalbard margin evolved to its present rifted configuration through a complex strike-slip history of both transtension and transpression. Because the Paleogene plate boundary, the De Geer Line, lay just west of Spitsbergen, many of the details of this structural evolution are contained in a narrow fold and thrust belt, and within a series of sedimentary basins, on Spitsbergen. The early to mid-Paleocene Central Basin was of extensional (possibly transtensional) origin, and contains more than 800 m of clastic deposits. It evolved from a series of partly connected coal basins to a single, open-marine basin. The late Paleocene to early Eocene Central Basin, of transpressional origin, was infilled by more than 1.5 km of clastic sediments from deltas, which prograded out from the rising orogenic belt. The fold and thrust belt of western Spitsbergen, mainly of late Paleocene to Eocene age, was also a product of transpression. Forlandsundet Graben, infilled by as much as 5 km of alluvial and marine elastics, probably formed from late Eocene collapse of the crest of the orogenic belt, or from extension adjacent to a curved fault zone. Rift basins, up to 7 km deep, developed west of Svalbard as the continental margin changed, beginning in the early Oligocene, from a strike-slip to a rifted regime.