DEEP-SEA FANS
Thierry Mulder
1 and Heiko Hüneke
2
1
University of Bordeaux, Talence, France
2
Institute of Geography and Geology, Ernst Moritz Arndt
University, Greifswald, Germany
Synonyms
Single-point-sourced turbidite system; Submarine fan
Definition
The term “deep-sea fan” has been coined by Normark
(1970) to describe modern turbidite systems with a point
source that typically display a fan-shaped outline. This
morphological analysis was based on the Pleistocene Californian fans San Lucas and Astoria. Mutti and Ricci
Lucchi (1972) used a similar model to describe the
fan-shaped facies association of Cretaceous and Tertiary
turbidite systems in the Apennines and Spanish Pyrenees.
The depositional system
Models that are more recent try to make a synthesis
between morphology, sedimentary processes, depositional environment, and sedimentary facies (Walker,
1978; Mutti, 1979; Barnes and Normark, 1985). They
include control factors such as sedimentary source, tectonic context, and eustatic changes.
The term “turbidite system” was thus preferentially
used to embrace all deepwater clastic depositional systems. The environmental model of Reading and Richards
(1994) includes (a) submarine fans controlled by singlepoint-sourced supply, (b) submarine ramps displaying
multiple-point-sourced delivery, and (c) slope aprons with
line-sourced supply. Based on the lithology, mud-rich,
mud-/sand-rich, sand-rich, or gravel-rich systems are
differentiated.
Mud-rich submarine fans are the typical turbidite systems of modern passive continental margins. The largest
fans (10
5
–10
6 km
2
) are the Bengal, Indus, Amazon, Mississippi, and Zaire fans. Much of the clastic material of
these high-efficiency, open-ocean fans is typically supplied during floods from major rivers.
The modern mud-rich submarine fans are subdivided
into canyon, channel-levee, and lobe complexes. The canyon usually largely incises the continental slope and shelf,
sometimes up to river mouth. On the continental rise, it
opens on a channel-levee complex including several generations of stacked channel-levees. The channel is usually
meandering and aggradational and bordered with bird
wing-shaped (in a transversal cross section) levees built
above the fan surface. Levees progressively diminish in
height and grain size and pass into lobes extending in the
abyssal plain. Lobes are first channeled and become
unchanneled with increasing distance.
Today, classification of deep-sea turbidite systems has
been
officially
abandoned
(Walker,
1992).
Sedimentologists prefer the “do-it-yourself” toolbox using
the architectural element concept (Miall, 1985).
Bibliography
Barnes, P. M., and Normark, W. R., 1985. Diagnostic parameters for
comparing modern submarine fans and ancient turbidite systems. In Bouma, A., Normark, W., and Barnes, N. (eds.), Submarine Fans and Related Turbidite Systems. New York: Springer,
pp. 13–14.
Miall, A. D., 1985. Architectural-element analysis: a new method of
facies analysis applied to fluvial deposits. Earth-Science
Reviews, 22, 261–308.
Mutti, E., 1979. Turbidites et cônes sous-marins profonds. In Homewood, P. (ed.), Se ´dimentation De ´tritique (Fluviatile, Littorale et
Marine). Fribourg: Institut de Géologie de l’Université de Fribourg, pp. 353–419. Short Course.
Mutti, E., and Ricci Lucchi, F., 1972. Le torbiditi dell’Appennino
settentrionale: introductione all’analisi di facies. Memorie della
Societa’ Geologica Italiana, 11, 161–199.
Normark, W. R., 1970. Growth patterns of deep-sea fans. American
Association of Petroleum Geologists Bulletin, 54, 2170–2195.
Reading, H. G., and Richards, M. T., 1994. The classification of
deep-water siliciclastic depositional systems by grain size and
feeder systems. American Association of Petroleum Geologists
Bulletin, 78, 792–822.
Richards, M., Bowman, M., and Reading, H., 1998. Submarine-fan
systems I: characterization and stratigraphic prediction. Marine
and Petroleum Geology, 15, 689–717.
Walker, R. G., 1978. Deep-water sandstone facies and ancient submarine fans: models for exploration for stratigraphic traps.
American Association of Petroleum Geologists Bulletin, 62,
932–966.
Walker, R. G., 1992. Turbidites and submarine fans. In Walker,
R. G., and James, N. P. (eds.), Facies Models: Response to Sea
Level Changes. St. John’s: Geological Association of Canada,
pp. 1–14. GEOtext 1.
Cross-references
Bouma Sequence
Continental Rise
Continental Slope
Deep-sea Sediments
Submarine Canyons
Turbidites
DEEP-SEA SEDIMENTS
Mitchell Lyle
College of Earth, Ocean, and Atmospheric Sciences,
Oregon State University, Corvallis, OR, USA
Synonyms
Pelagic sediments
Definition
The term “deep-sea sediments” or the interchangeable
term “pelagic sediments” refers to sediments that deposit
156
DEEP-SEA FANS
Thierry Mulder
1 and Heiko Hüneke
2
1
University of Bordeaux, Talence, France
2
Institute of Geography and Geology, Ernst Moritz Arndt
University, Greifswald, Germany
Synonyms
Single-point-sourced turbidite system; Submarine fan
Definition
The term “deep-sea fan” has been coined by Normark
(1970) to describe modern turbidite systems with a point
source that typically display a fan-shaped outline. This
morphological analysis was based on the Pleistocene Californian fans San Lucas and Astoria. Mutti and Ricci
Lucchi (1972) used a similar model to describe the
fan-shaped facies association of Cretaceous and Tertiary
turbidite systems in the Apennines and Spanish Pyrenees.
The depositional system
Models that are more recent try to make a synthesis
between morphology, sedimentary processes, depositional environment, and sedimentary facies (Walker,
1978; Mutti, 1979; Barnes and Normark, 1985). They
include control factors such as sedimentary source, tectonic context, and eustatic changes.
The term “turbidite system” was thus preferentially
used to embrace all deepwater clastic depositional systems. The environmental model of Reading and Richards
(1994) includes (a) submarine fans controlled by singlepoint-sourced supply, (b) submarine ramps displaying
multiple-point-sourced delivery, and (c) slope aprons with
line-sourced supply. Based on the lithology, mud-rich,
mud-/sand-rich, sand-rich, or gravel-rich systems are
differentiated.
Mud-rich submarine fans are the typical turbidite systems of modern passive continental margins. The largest
fans (10
5
–10
6 km
2
) are the Bengal, Indus, Amazon, Mississippi, and Zaire fans. Much of the clastic material of
these high-efficiency, open-ocean fans is typically supplied during floods from major rivers.
The modern mud-rich submarine fans are subdivided
into canyon, channel-levee, and lobe complexes. The canyon usually largely incises the continental slope and shelf,
sometimes up to river mouth. On the continental rise, it
opens on a channel-levee complex including several generations of stacked channel-levees. The channel is usually
meandering and aggradational and bordered with bird
wing-shaped (in a transversal cross section) levees built
above the fan surface. Levees progressively diminish in
height and grain size and pass into lobes extending in the
abyssal plain. Lobes are first channeled and become
unchanneled with increasing distance.
Today, classification of deep-sea turbidite systems has
been
officially
abandoned
(Walker,
1992).
Sedimentologists prefer the “do-it-yourself” toolbox using
the architectural element concept (Miall, 1985).
Bibliography
Barnes, P. M., and Normark, W. R., 1985. Diagnostic parameters for
comparing modern submarine fans and ancient turbidite systems. In Bouma, A., Normark, W., and Barnes, N. (eds.), Submarine Fans and Related Turbidite Systems. New York: Springer,
pp. 13–14.
Miall, A. D., 1985. Architectural-element analysis: a new method of
facies analysis applied to fluvial deposits. Earth-Science
Reviews, 22, 261–308.
Mutti, E., 1979. Turbidites et cônes sous-marins profonds. In Homewood, P. (ed.), Se ´dimentation De ´tritique (Fluviatile, Littorale et
Marine). Fribourg: Institut de Géologie de l’Université de Fribourg, pp. 353–419. Short Course.
Mutti, E., and Ricci Lucchi, F., 1972. Le torbiditi dell’Appennino
settentrionale: introductione all’analisi di facies. Memorie della
Societa’ Geologica Italiana, 11, 161–199.
Normark, W. R., 1970. Growth patterns of deep-sea fans. American
Association of Petroleum Geologists Bulletin, 54, 2170–2195.
Reading, H. G., and Richards, M. T., 1994. The classification of
deep-water siliciclastic depositional systems by grain size and
feeder systems. American Association of Petroleum Geologists
Bulletin, 78, 792–822.
Richards, M., Bowman, M., and Reading, H., 1998. Submarine-fan
systems I: characterization and stratigraphic prediction. Marine
and Petroleum Geology, 15, 689–717.
Walker, R. G., 1978. Deep-water sandstone facies and ancient submarine fans: models for exploration for stratigraphic traps.
American Association of Petroleum Geologists Bulletin, 62,
932–966.
Walker, R. G., 1992. Turbidites and submarine fans. In Walker,
R. G., and James, N. P. (eds.), Facies Models: Response to Sea
Level Changes. St. John’s: Geological Association of Canada,
pp. 1–14. GEOtext 1.
Cross-references
Bouma Sequence
Continental Rise
Continental Slope
Deep-sea Sediments
Submarine Canyons
Turbidites
DEEP-SEA SEDIMENTS
Mitchell Lyle
College of Earth, Ocean, and Atmospheric Sciences,
Oregon State University, Corvallis, OR, USA
Synonyms
Pelagic sediments
Definition
The term “deep-sea sediments” or the interchangeable
term “pelagic sediments” refers to sediments that deposit
156
DEEP-SEA FANS