Enormous volumes of basaltic magma are generated from partial melting of peridotite under mid-ocean ridges
due to the lower pressure in this shallow region of the asthenosphere.
Pyrrhotite and pyrite have both been described from active black smoker chimneys and high temperature massive sulfides recovered from mid-ocean ridge
vent fields [44, 113, 114].
Consequently, the mid-ocean ridge
there is covered by sediment that is a few hundred to a few thousand meters thick .
The La/[Sm.sub.pmn] correlates positively with [sup.87]Sr/[sup.86]Sr and negatively with [sup.143]Nd/[sup.144]Nd in NE Pacific mid-ocean ridge
lavas, but little correlation exists among the alkalic lavas alone (Fig.
4 Which of the following best explains why the walls of the mid-ocean ridge
Unlike most other mid-ocean ridges
, the East Pacific Rise as a whole has not moved east-west for 50,000,000 to 80,000,000 years, even as parts of it have been spreading asymmetrically.
Are they produced in large ocean basins at mid-ocean ridges
or in more confined settings like forearcs, arcs or back-arc basins close to continental margins?
On average, there is about one vent site for every 100 kilometers (62 miles) of mid-ocean ridge
, so it followed that there should be just one vent site along the entire Mid-Cayman Spreading Center.
The rise is part of a giant undersea mountain range, named the mid-ocean ridge
, that runs the length of Earth's major oceans.
Voluminous basaltic magmas erupt at mid-oceanic ridges (mid-ocean ridge
basalts, MORB) as a consequence of mantle upwelling beneath spreading plates.
Geologists can take a peek at this in Iceland, where the Atlantic's mid-ocean ridge
surfaces above the waves.
10) associated basalts characterized by Th and LREE depletion bear resemblance to mid-ocean ridge