Rare earth element inversions of the melt distribution in the mantle source region suggest that sufficient melt is generated under normal oceanic spreading centers to produce an 8.3卤1.5 km thick igneous crust. The difference between the thickness estimates from seismics and from rare earth element ...
Nearly three-quarters of the Earth's crust lies beneath the world's oceans and marginal seas; approximately 60% of its surface can be considered ‘oceanic’. Most of the oceanic crust has been formed by magmatic processes that occur at mid-ocean ridges, although in some regions significant vo...
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
Learn about the oceanic crust, including the oceanic crust definition, oceanic crust thickness and density, oceanic crust composition, and other...
Bioalteration of basaltic glass in theoceaniccrust. From theCambridge English Corpus These pressures are equivalent to 57-46 km depth beneath anoceaniccrust-mantle hanging-wall, a much greater thickness than can be accounted for by the thickness of the ophiolite. ...
Bioalteration of basaltic glass in the oceaniccrust. These pressures are equivalent to 57-46 km depth beneath an oceaniccrust-mantle hanging-wall, a much greater thickness than can be accounted for by the thickness of the ophiolite. Partial melting of subducting oceaniccrust. The evidence of...
A. thinner B. thicker C. of the same thickness D. more liquid 相关知识点: 试题来源: 解析 B。解析:大陆地壳和大洋地壳在厚度上有明显差异。大陆地壳相对较厚,平均厚度约35千米,而大洋地壳较薄,平均厚度约7千米。这是因为大陆地壳包含更多的硅铝层,物质组成和地球内部构造过程使得其厚度较大洋地壳厚。反...
The Earth's crust is the outermost layer of our planet, composed of solid rock. The Earth's crust varies in thickness from about 5 to 70 k...
Oceanic crustis created asmagmarises to fill the gap between divergingtectonic platesand is consumed insubduction zones. It is geologically young, with a mean age of 60Ma, and is thin, averaging 6.5km in thickness. Oceanic crust consists almost exclusively of extrusivebasaltand its intrusive equiv...
Examination of oceanic seismic refraction results indicates a correlation between total crustal thickness and spreading rate, with slower spreading producing thinner crust. The effect is seen at spreading rates less than about 20 mm yr 1 . The crustal thickness and its dependence on spreading rate ar...