What is submarine fan in geology?

What is submarine fan in geology?

Submarine fan, accumulation of land-derived sediment on the deep seafloor; in configuration, a fan is like the section of a very low cone, with its apex at the lower mouth of a submarine canyon incised into a continental slope.

What is the name for a submarine fan?

Abyssal fans, also known as deep-sea fans, underwater deltas, and submarine fans, are underwater geological structures associated with large-scale sediment deposition and formed by turbidity currents.

Which Ichnofacies do you associate with submarine fans?

The ichnocoenosis B is anomalous in submarine fans. The dynamics associated with the coarse-grained inner channelized part of this submarine fan are a precluding factor in the development of highly specialized traces.

How are submarine fans formed?

Sediment transported down submarine canyons is deposited to form submarine fans at the mouth of the canyon where the seabed flattens out adjacent to the deep ocean floor.

Why are submarine fans important?

Submarine fans constitute important sites of sediment accumulation in the world’s oceans (Fig. Map showing locations of modern and ancient deep-water systems, commonly known as submarine fans, discussed during the COMFAN Meeting in 1982 (Bouma et al., 1985).

What current feeds submarine fans?

Note that although coarse-grained deltas are sometimes referred to as fan deltas and are largely submarine, the term submarine fan is restricted to fan-shaped bodies that are deposited by mass-flow, mainly turbidity current, processes.

What causes submarine canyons?

Submarine canyons are formed via erosion and mass wasting events, particularly on steep continental slopes but also on the flanks of volcanic islands. Over geologic time, submarine canyons are formed by the repeated erosion of the slope by turbidity currents flowing down the canyon axis.

Are trace fossils unique?

These fossils are different from body fossils that preserve the actual remains of a body such as shells or bones. Trace fossils are classified based on an organism’s shape and behaviors rather than on its physical form.

What is the relationship between submarine canyons turbidity currents and deep sea fans?

These mixtures, termed sediment density flows (and commonly referred to as turbidity currents), are responsible for the offshore transport of large amounts of sediment into the deep sea and accumulation of submarine fans (e.g., Talling et al., 2015).

Where are the thinnest sediments generally found in deep ocean basins?

mid-ocean ridges
The thinnest layers of marine sediments are generally found in deep-ocean basins near mid-ocean ridges. However, as the ocean crusts ages and moves away from the spreading centers, time allows sediments to gradually accumulate on the seafloor.

What is the most important submarine canyon?

Examples

• Monterey Canyon, off the coast of central California.
• Nazaré Canyon, off the coast of Portugal, reaches abyssal depths of 5,000 m.
• Pribilof Canyon, in the Bering Sea.
• Whittard Canyon, Atlantic Ocean off southwest Ireland.
• Zhemchug Canyon the deepest and joint-widest submarine canyon in the world, in the Bering Sea.

Why are submarine canyons important?

The combination of steep rocky slopes, strong currents and enhanced access to food makes submarine canyons places of special ecological significance. Canyons often are iconic, defining features of marine reserves in many locations because of their association with higher biomass and biodiversity.

What are the sedimentary characteristics of the turbidite fan?

Multi-stage confined channel complex. The channel complex is developed around the middle slope, and is the middle-large broad-gentle valley in the shape. The channel has a large scale, and cut the underlying strata deeply; on the horizon seismic attribute, the lateral distribution of the channel is wide (He et al., 2007).

What are the characteristics of a submarine fan?

The purpose of this review is to provide an up-to-date account of submarine-fan deposits primarily in terms of their sedimentologic 0012-8252/88/$03.50 ~ 1988 Elsevier Science Publishers B.V. 384 characteristics. A critical review of conven- tional submarine-fan models is presented.

Why are turbidite systems important in the deep sea?

Turbidite systems or submarine fans are considered the most important clastic accumulations in the deep sea and represent the sediment-transfer system between the hinterland source area and the deep-sea depositional sink. Their deposits contain information about global factors and local factors.

Why are submarine fans important to hydro-carbon reservoirs?

Submarine fans constitute major hydro- carbon reservoirs throughout the world. Con- sequently, a clear understanding of their geometry, facies relationships, and reservoir quality is critical for exploring and exploiting these deposits effectively.