The characteristic rocks of obducted oceanic lithosphere are the ophiolites. Ophiolites are an assemblage of oceanic lithosphere rocks that have been emplaced onto a continent.

What does an obduction mean?

: an act or instance of drawing or laying something (as a covering) over.

What is obduction process?

[ ŏb-dŭk′shən ] A geologic process in which the edge of a tectonic plate consisting of oceanic crust is thrust over the edge of an adjacent plate consisting of continental crust. Compare subduction.

What ophiolite means?

Ophiolite is thrust sheets of ancient oceanic crust and upper part of mantle rocks that have been uplifted and exposed above sea level and often emplaced on top of the continental lithosphere.

What is the difference between obduction and subduction?

As nouns the difference between obduction and subduction

is that obduction is (obsolete) the act of drawing or laying over, as a covering while subduction is the action of being pushed or drawn beneath another object.

Structural geology and tectonics: Ophiolite obduction

Can I play obduction?

Obduction will run on PC system with Windows 7 SP1 64 bit or newer and upwards. Additionally it has a Mac version.

What feature is commonly seen in an area of obduction?

In such a collision, called obduction, layers of rock are bent into folds such as those of the State College area, or broken into thrust faults such as those under the Blue Ridge and the Great Smokies.

What causes an ophiolite?

ultramafic rocks are known as ophiolites. Many geologists believe that ophiolites formed at oceanic ridges were emplaced by tectonic forces at convergent plate boundaries and then became exposed in highly deformed orogenic (mountain) belts.

What is ophiolite used for?

Ophiolites in orogenic (mountain building) belts represent sutures between two continental plates. Their recognition is therefore important in tectonic reconstructions.

What is ophiolite where is it located in the Philippines?

Abstract. The Zambales Ophiolite Complex (ZOC) in the western portion of Luzon Island, Philippines represents a typical exposure of an emplaced crust-upper mantle section of an ancient lithosphere.

Which mountains were formed by obduction and are still growing today?

The Great Smoky Mountains were raised to their present elevation by obduction, when Africa and Europe collided with North America as the proto-Atlantic Ocean closed.

What is abduction of plates?

ABDUCTION Abduction is the overthrusting of continental crust by oceanic crust or mantle rocks at a convergent plate boundary This process is uncommon as the denser oceanic lithosphere usually subducts underneath the less dense continental plate.

Why do plates get subducted?

Subduction is possible because the cold oceanic lithosphere is slightly denser than the underlying asthenosphere, the hot, ductile layer in the upper mantle underlying the cold, rigid lithosphere. Once initiated, stable subduction is driven mostly by the negative buoyancy of the dense subducting lithosphere.

What causes Obduction?

Obduction occurs where a fragment of continental crust is caught in a subduction zone with resulting overthrusting of oceanic mafic and ultramafic rocks from the mantle onto the continental crust. ... When two continental plates collide, obduction of the oceanic crust between them is often a part of the resulting orogeny.

What's it called when one plate goes under another?

Plates Subduct. When an ocean plate collides with another ocean plate or with a plate carrying continents, one plate will bend and slide under the other. This process is called subduction. A deep ocean trench forms at this subduction boundary.

What does abducted mean in English?

1 : to seize and take away (a person) by force The girl was abducted by kidnappers. 2 : to draw or spread away (a part of the body, such as a limb or the fingers) from a position near or parallel to the median axis of the body or from the axis of a limb a muscle that abducts the arm.

What are the 3 main layers in an ophiolite?

Sediments (layer 1) Volcanic Crust (layer 2) Plutonic Crust (layer 3) Mantle Harzburgite (layer 4) 4 layers distinguished from Geophysics: Typical Ophiolite: 1.

Where is the ophiolite complex located?

The Baie Verte Lineament, located in the Burlington Peninsula, northwest Newfoundland, is a steeply-dipping linear belt 90 km long by 1 to 5 km wide containing a variably disrupted ophiolite suite and other mainly mafic volcaniclastic and volcanic rocks that originally overlay the ophiolite complex.

What is ophiolite PDF?

Ophiolites are suites of temporally and spatially associated ultramafic, mafic, and felsic rocks that are interpreted to be remnants of ancient oceanic crust and upper mantle. Ophiolites show significant variations in their internal structure, geochemical fingerprints, and emplacement mechanisms.

What is ophiolite sequence?

Ophiolite sequences are indicators of sea-floor spreading where the oceanic crust is thinned by the forces of plate tectonics, and magma rises to the sea's floor and generates new crust.

Where do ophiolite suite of rocks occur?

An ophiolite is a section of Earth's oceanic crust and the underlying upper mantle that has been uplifted and exposed above sea level and often emplaced onto continental crustal rocks.

What are the rock type members of an ophiolite sequence?

Franciscan ophiolites consist of fragments of peridotite, gabbro and basaltic rocks, representing fragments of a mid-ocean ridge setting. The igneous rocks are associated with pelagic chert and limestone.

What type of landforms does subduction cause?

Various formations such as mountain ranges, islands, and trenches are caused by subduction and the volcanoes and earthquakes it triggers. In addition to causing earthquakes, subduction can also trigger tsunamis. When the older plate is holding a continent however, it does not sink, which is reassuring.

What type of earthquake happens at areas of subduction?

Megathrust earthquakes are almost exclusive to tectonic subduction zones and are often associated with the Pacific and Indian Oceans. These subduction zones are not only responsible for megathrust earthquakes but are also largely responsible for the volcanic activity associated with the Pacific Ring of Fire.

Where are trenches found?

Ocean trenches are found in every ocean basin on the planet, although the deepest ocean trenches ring the Pacific as part of the so-called “Ring of Fire” that also includes active volcanoes and earthquake zones. Ocean trenches are a result of tectonic activity, which describes the movement of the Earth's lithosphere.