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.
Oceanic crust is formed at an oceanic ridge, while the lithosphere is subducted back into the asthenosphere at trenches. The oceanic trenches are hemispheric-scale long but narrow topographic depressions of the sea floor. They are also the deepest parts of the ocean floor. Oceanic trenches are a distinctive morphological feature of convergent plate boundaries, along which lithospheric plates move towards each other at rates that vary from a few mm to over ten cm per year.