How does a submarine canyon and fan form?
Table of Contents
- 1 How does a submarine canyon and fan form?
- 2 What is a submarine fan in geology?
- 3 Which type of rock would likely form from a submarine fan?
- 4 How are submarine canyons and trenches different?
- 5 How cross-bedding is formed?
- 6 Why are submarine fans cut off from sediment supply?
- 7 Are submarine fan systems a potential area of hydrocarbon exploration?
How does a submarine canyon and fan form?
The formation of submarine canyons is believed to occur as the result of at least two main process: 1) erosion by turbidity current erosion; and 2) slumping and mass wasting of the continental slope. Turbidites are deposited at the downstream mouths or ends of canyons, building an abyssal fan.
What do deep sea fans consist of?
Modern and ancient submarine fans contain a complex blend of gravel, sand, and mud (Shanmugam and Moiola, 1988).
What is a 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.
How are submarine canyons formed?
Over geologic time, submarine canyons are formed by the repeated erosion of the slope by turbidity currents flowing down the canyon axis. Retrogressive slope failures may expand the canyon head, eroding landwards and expanding the size of the canyon.
Which type of rock would likely form from a submarine fan?
5.5: Depositional Environments
| Location | Sediment | Common Rock Types |
|---|---|---|
| Submarine fan | graded Bouma sequences, alternating sand/mud | clastic rocks |
| Continental slope | mud, possible sand, countourites | shale, siltstone, limestone |
| Lower shoreface | laminated sand | sandstone |
| Upper shoreface | planar sand | sandstone |
Where are submarine fans formed?
Formation. Abyssal (or submarine) fans are formed from turbidity currents. These currents begin when a geologic activity pushes sediments over the edge of a continental shelf and down the continental slope, creating an underwater landslide.
How are submarine canyons and trenches different?
Submarine canyons are so called because they resemble canyons made by rivers on land. Unlike deep-sea trenches, which are found in areas where one tectonic plate slides beneath another, undersea canyons are found along the slopes of most continental margins.
What current feeds submarine fans?
Abyssal (or submarine) fans are formed from turbidity currents. These currents begin when a geologic activity pushes sediments over the edge of a continental shelf and down the continental slope, creating an underwater landslide.
How cross-bedding is formed?
Cross-bedding is formed by the downstream migration of bedforms such as ripples or dunes in a flowing fluid. Cross-bedding can form in any environment in which a fluid flows over a bed with mobile material. It is most common in stream deposits (consisting of sand and gravel), tidal areas, and in aeolian dunes.
What is a submarine fan?
A submarine fan is a body of sediment on the sea floor deposited by mass-flow processes that may be fan-shaped, but more elongate, lobate geometries are also common.
Why are submarine fans cut off from sediment supply?
Submarine fans tend to be cut off from sediment supply, particularly in the case of narrow shelves, as most sediment is trapped in landward positions on the shelf (Catuneanu, 2003). R. Bastia, M. Radhakrishna, in Developments in Petroleum Science, 2012
What is a fan fan in geology?
Submarine fan, accumulation of land-derived sedimenton 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 canyonincised into a continental slope.
Are submarine fan systems a potential area of hydrocarbon exploration?
Submarine fan systems are known to be potential areas of hydrocarbon exploration (Lopez, 2001) as they form the largest deep-water sediment bodies near continental margins.