where does an accretionary wedge form? course hero

Where does an accretionary wedge form?

Accretionary wedges form at the bottom of ocean trenches created at some convergent plate boundaries.Dec 7, 2021

What causes accretionary wedge?

An accretionary wedge is basically a hodge-podge collection of various sediments and rocks, scraped up and squished together where two tectonic plates collide and one plate subducts underneath another.Jun 5, 2011

What are the components of an accretionary wedge?

Accretionary wedges are chaotic deposits consisting of original rock fragments and metamorphic rock. The original igneous and sedimentary rock removed from the down-going plate is often turned into metamorphic rock due to the huge amounts of pressure they experience.

Is Barbados an accretionary wedge?

Similarly, Barbados has an accretionary wedge between it and the North American plate, with a convergent rate of ~3cm/a (Zhao et al., 1986). The Barbados wedge is unusually wide, approximately 300 km (Zhao et al., 1986).

Where is the forearc basin located?

Forearc basins are marine depositional basins on the trench side of arcs (Fig. 3.16A), and they vary in size and abundance with the evolutionary stage of an arc. In continental margin arcs, such as the Sunda Arc in Indonesia, forearc basins range up to 700 km in strike length.

Where is an accretionary prism located?

convergent plate boundariesAccretionary prisms form at the leading edge of convergent plate boundaries by skimming-off sediments and rocks of the lower plate. In detail, the accretion process involves offscraping of rocks and sediments at the front of the prism or underplating (emplacement beneath the prism).

How does a forearc basin form?

Forearc basin is a sedimentary basin formed in the arc-trench gap between a volcanic arc and plate subduction zone (Figure 1) [1].

What is the meaning of accretionary wedge?

Sediments, the top layer of material on a tectonic plate, that accumulate and deform where oceanic and continental plates collide. These sediments are scraped off the top of the downgoing oceanic crustal plate and are appended to the edge of the continental plate.

Which tectonic plate is moving the fastest?

The Pacific PlateThe Pacific Plate is the fastest at over 10 cm/y in some areas, followed by the Australian and Nazca Plates. The North American Plate is one of the slowest, averaging around 1 cm/y in the south up to almost 4 cm/y in the north.

What is back arc basin in geology?

back-arc basin, submarine basin that forms behind an island arc. Such basins are typically found along the western margin of the Pacific Ocean near the convergence of two tectonic plates.

Accretionary Wedge and Plate Tectonics

If you live in a climate that gets cold in the winter, you've likely had to shovel snow off the sidewalk. To do this, you have to take a shovel and scrape the snow back in a straight line, revealing the concrete below. (Then you repeat until the sidewalk's clear or your arms are too sore to move, whichever comes first.)

What Does an Accretionary Wedge Look Like?

Going back to our analogy of shoveling snow, if you look down at the snow you are scraping off the concrete, it will look like an un-orderly jumbled mess of snow sitting on top of your shovel. Accretionary wedges look much the same way. They have jumbled deposits of original rock layers and metamorphic rock.