Submarine fans

Example Mid-Atlantic Ridge. North American Atlantic and Gulf Coast Mesozoic and Cenozoic. Aleutian trench. Siwalik scries of India, Bengal submarine fan. Triassic of Eastern North America. Michigan and Eastern interior basins of North America. 

Marine mass-flow or grain-flow dominated submarine fan system... 

Magnus Macaulay et al. (1993) Emery et at. (1993) Kimmeridge Clay Formation Submarine fan sst. U. Jurassic 2990 116... 

Of the oilfields involved (Fig. 1), the majority have as reservoirs deltaic sandstones of the Middle Jurassic Brent Group and equivalents, although the furthest north and south, Magnus and South Brae, have Upper Jurassic submarine fan sandstone reservoirs. The general Jurassic stratigraphy of the northern North Sea is shown in Fig. 2. 

The range in compositions is much narrower in Upper Jurassic submarine fan sandstones than in deltaic Middle Jurassic sandstones, although both have major modes at 6 C -10%o. This difference is due to the exposure of the Middle Jurassic deltaic sediments to a wider range of carbon sources and bacterial isotope-fractionation processes than the... 

Continental Slope and Continental Rise 2.5.3.1 Siliciclastic Slopes and Submarine Fans... 

Bouma, A.H., Normark, W.R., and Barnes, N.E., eds. 1985. Submarine Fans and Related Turbidite Systems. Springer-Verlag, New York, 351pp. 

Nelson, C.H., and Kulm, L.D. 1973. Submarine fans and channels. In Turbidites and Deep Water Sedimentation, Middleton, G.V. and Bouma, A.H., ed.. Society of Economic Paleontologists and Mineralogists, Short Course Pacific Section, Anaheim, CA, pp. 39-78. 

Normark, W.R., Piper, D.J.W., and Hess, G.R. 1979. Distributary chaimels, sandy lobes and meso-topography of navy submarine fan, California borderland with application to ancient fan sediments. Sedimentology, 26 749-774. 

Piper, D.J.W, and Normark, W.R. 1983. Turbidite depositional patterns and flow characteristics, navy submarine fan, CaUfomia borderland. Sedimentology, 30 681-694. 

Walker, R.G. 1978. Deep-sea sandstone facies and ancient submarine fans Model for exploration for stratigraphic traps. American Association of Petroleum Geologists Bulletin, 62 932-966. 

Walker, R.G. 1992b. Turbidite and submarine fans. In Facies Models Response to Sea-Level Change, Walker, R.G., and James, N.R, eds.. Geological Association of Canada, St. John s, Canada, pp. 239-264. 

Most of the hydrocarbons (gas and oil) occur in sedimentary rocks that were generated in different depositional environments (e.g. river charmels, delta systems, submarine fans, carbonate mounds and reefs). Seismic waves penetrating into and reflected within sedimentary rock bodies yield a seismic image of their external shape and of their internal texture. Therefore, the analysis of the external shape of seismic bodies and its internal textures, which is called seismic facies analysis [2], helps to specify the depositional environment of the investigated sedimentary rocks. An analysis of the seismic facies is a must in seismic interpretation to determine the depositional environment and to locate potential reservoirs, especially in complex oilfields. 

Generally, different sedimentary rocks yield different seismic facies. The seismic facies of a buried carbonate mound or reef, for example, differs significantly from a submarine fan or a delta system. Hence, each depositional system has its particular seismic facies. 

Concave Upward Complex. The texture consists of a complex arrangement of parallel and wavy events. The seismic events surrounding the mound show onlap. This texture is characteristic for submarine fans. 

Biomarker Carbon-Isotope Analyses. While a forest/non-forest carbon-isotope signature is readily identifiable in terrestrial environments, it is very difiScult to obtain complete, well dated fluvial sequences. Complete sedimentary sequences are readily available fi-om the submarine fan deposits which lie off the mouth of the Amazon River 82 but the analysis of bulk sediments fi om the marine environment is not appropriate because terrestrially-derived riverbome carbon in the sample rapidly becomes mbced with marine-derived carbon offshore fi om the river mouth. 

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