Αποτελέσματα Αναζήτησης
The crust is separated into two parts: the thin oceanic crust (between ∼3 and 10 km thick) with an approximate basaltic composition, and the thick continental crust (in average ∼35-40 km...
- Login
The crust is separated into two parts: the thin oceanic...
- Help Center
© 2008-2024 ResearchGate GmbH. All rights reserved. Terms;...
- Login
1 Ιαν 2018 · Oceanic crust is the outermost solid layer of the lithospheric tectonic plates under the oceans that covers much of the Earth’s surface. It has a distinctive basaltic composition characterized by rocks that have relatively low concentrations of potassium and other highly incompatible trace elements (those typically excluded from minerals that ...
Oceanic crust is created as magma rises to fill the gap between diverging tectonic plates and is consumed in subduction zones. It is geologically young, with a mean age of 60.
We analyze this new fundamental characteristic of the crust by ternary diagrams based on seismic models for continental and oceanic crustal structure in the northern Eurasia-northern Atlantics region and for selected oceanic provinces of different geodynamic origin, where seismic models for the crust are available.
• Describe the various components of oceanic crust: pillow basalts, sheeted dykes, gabbro bodies, layered gabbro, and layered ultramafic rock. • Describe the age distribution of oceanic crust, and explain why all of it is relatively young.
oceanic crust, the outermost layer of Earth’s lithosphere that is found under the oceans and formed at spreading centres on oceanic ridges, which occur at divergent plate boundaries. Oceanic crust is about 6 km (4 miles) thick. It is composed of several layers, not including the overlying sediment.
24 Απρ 2024 · As we discussed in Chapter 10, oceanic crust is formed at sea-floor spreading ridges from magma generated by decompression melting of hot upward-moving mantle rock (Figure 18.2.3 18.2. 3). About 10% of the mantle rock melts under these conditions, producing mafic magma.
