ophiolite
Quick Summary
Ophiolites are sequences of rocks that represent fragments of oceanic crust and the underlying upper mantle, which have been tectonically emplaced onto continental crust. These rock assemblages are typically found in deformed mountain belts and provide crucial evidence for past plate tectonic activity.12
An ophiolite sequence, from top to bottom, generally includes:
* Oceanic sediments (like cherts)
* Pillow basalts
* Sheeted basic dikes
* Gabbros
* Ultramafic rocks (such as serpentinized harzburgite or lherzolite)2
Geologists believe that most ophiolites formed at divergent plate boundaries, such as mid-ocean ridges, and were later thrust onto land during collisions between tectonic plates. The study of ophiolites is vital for understanding the composition and formation processes of oceanic crust and the mechanisms by which these fragments are preserved on continents.13
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PrecambrianStructure and formation of greenstone-granite belts…swarms that occur in many ophiolites of Mesozoic-Cenozoic origin, such as in the Troodos Mountains in Cyprus. They are the hallmark of a modern oceanic crust that formed at an oceanic ridge. Also, like modern ophiolites, a few seem to have been covered by thrusting onto continental crust. Many belts,…
Read More…swarms that occur in many ophiolites of Mesozoic-Cenozoic origin, such as in the Troodos Mountains in Cyprus. They are the hallmark of a modern oceanic crust that formed at an oceanic ridge. Also, like modern ophiolites, a few seem to have been covered by thrusting onto continental crust. Many belts,…
Read More- PrecambrianOphiolites
Phanerozoic ophiolites are considered to be fragments of ocean floor that have been trapped between island arcs and continental plates that collided or that have been thrust onto the shelf sediments of continental margins. They consist of a downward sequence of oceanic sediments such…
Read MorePhanerozoic ophiolites are considered to be fragments of ocean floor that have been trapped between island arcs and continental plates that collided or that have been thrust onto the shelf sediments of continental margins. They consist of a downward sequence of oceanic sediments such…
Read More