What is the 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.
How do ophiolites form?
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 does an ophiolite represent?
Abstract. 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 the composition of ophiolite?
Ophiolite is a stratified igneous rock complex composed of upper basalt member, middle gabbro member and lower peridotite member (Fig. 1). Some large complexes measure more than 10 km thick, 100 km wide and 500 km long. The term “ophiolite” means “snake stone” in Greek.
What does ophiolite look like?
The name ophiolite means “snakestone” from “ophio” (snake) and “lithos” (stone) in Greek. The rock sequence is named for the brilliant green, snake-like serpentine minerals which form in altered ocean crust and mantle. Ophiolites are rare but nonetheless found throughout the world.
What is Obduction zone?
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.
How are ophiolites studied?
Several studies support the conclusion that ophiolites formed as oceanic lithosphere. Seismic velocity structure studies have provided most of the current knowledge of the oceanic crust’s composition.
How many layers of ophiolites are there?
Sediments (layer 1) Volcanic Crust (layer 2) Plutonic Crust (layer 3) Mantle Harzburgite (layer 4) 4 layers distinguished from Geophysics: Typical Ophiolite: 1.
Where are ophiolite found?
Ophiolites have been found in Cyprus, New Guinea, Newfoundland, California, and Oman. The Samail ophiolite in southeastern Oman has probably been studied in the greatest detail. The rocks probably formed in the Cretaceous not far from the what is now the Persian Gulf.
Where is ophiolite 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.
How does Obduction occur?
Obduction often occurs where a small tectonic plate is caught between two larger plates, with the crust (both island arc and oceanic) welding onto an adjacent continent as a new terrane. When two continental plates collide, obduction of the oceanic crust between them is often a part of the resulting orogeny.
How many GB is Obduction?
20 GB
Storage: 20 GB available space.