New Information for PY106. Class meets daily in SCI 111 from 9:00 to 10:30 a.m. NEW! Problems 38 and 64 of the chapter 24 assignment (which is due Wednesday, August 2) will be due at the start of class on Thursday, August 3. The rest of this assignment is still due at the usual time (at the start of discussion section on Wednesday, August 2). Concerning labs: The first lab will take place on Thursday, July 6, from 10:30 to 1:00 in the basement of SCI. Both lab sections, A and B, will meet at this time.
Oceanic crust is the uppermost layer of an oceanic tectonic plate. The crust overlies the solidified and uppermost layer of the mantle. The crust and the solid mantle layer together comprise an oceanic plate.The plates of the Earth together are referred to as the lithosphere.Oceanic crust is the result of erupted mantle material originating from below the plate, cooled and in most instances, modified chemically by seawater.This occurs mostly at mid-ocean ridges, but also at scattered hotspots, and also in rare but powerful occurences known as flood basalt eruptions.he crust overlies the solidified and uppermost layer of the mantle. The crust and the solid mantle layer together comprise an oceanic plate. The plates of the Earth together are referred to as the lithosphere.
Crust is consumed in subduction zones. When two plate move together, one of them must slide under the other one. This is called subduction. When an oceanic plate and a continental plate meet, the denser oceanic plate subducts under the less dense continental plate. The subducting plate slips down into the mantle where it is heated, melts and is recycled. Thus spreading centers and subduction zones act like a conveyor belt, manufacturing crust at one end and consuming it at the other. The deepest parts of the ocean occur in trenches along subduction zones.