What is the role of the mantle in plate tectonics?
The Earth’s mantle plays an important role in the evolution of the crust and provides the thermal and mechanical driving forces for plate tectonics. Because subducted plates are relatively cool, they decrease the temperature of nearby mantle, leaving relatively warm mantle in the regions between two subduction zones.
What is the purpose of the mantle in mollusks?
The mantle cavity functions as a respiratory chamber in most molluscs. In bivalves it is usually part of the feeding structure. In some molluscs the mantle cavity is a brood chamber, and in cephalopods and some bivalves such as scallops, it is a locomotory organ. The mantle is highly muscular.
What are the two functions of the mantle?
The mantle is an outgrowth of the body surface that drapes over the animal. The mantle produces the shell in mollusks such as clams and snails. The mantle also functions in respiration, waste disposal, and sensory reception. In addition, the mantle is related to another distinctive feature, the mantle cavity.
What is the purpose and function of the mantle?
It forms the outer wall of the mollusk’s body. The mantle encloses the mollusk’s visceral mass, which is its internal organs, including the heart, stomach, intestines, and gonads. The mantle is muscular, and many species have modified it to use for siphoning water for feeding and propulsion.
What is the composition of the lower mantle?
The lower mantle accounts for nearly half of the mass of the Earth. It is generally accepted that its mineralogy mostly consists of magnesium silicate perovskite (Mg,Fe,Al)(Si,Al)O3, magnesiowustite (Mg,Fe)O, and calcium silicate perovskite CaSiO3 (e.g. Irifune 1994; Kesson et. al. 1998).
What are the chemical compositions of the mantle?
In terms of its constituent elements, the mantle is made up of 44.8% oxygen, 21.5% silicon, and 22.8% magnesium. There’s also iron, aluminum, calcium, sodium, and potassium. These elements are all bound together in the form of silicate rocks, all of which take the form of oxides.
Is there calcium in mantle?
The “simplicity” of the mineralogy of the crust and mantle reflects the fact that eight chemical elements — oxygen, silicon, aluminum, iron, calcium, magnesium, sodium and potassium — account for about 99% of the weight of the crust and of the mantle. The mantle is enriched in iron, calciuim and magnesium.
Which layer has the least amount of density?
lithosphere
What is the most abundant element in mantle?
Mantle. The mass-abundance of the eight most abundant elements in the Earth’s mantle (see main article above) is approximately: oxygen 45%, magnesium 23%, silicon 22%, iron 5.8%, calcium 2.3%, aluminum 2.2%, sodium 0.3%, potassium 0.3%.
What are the sublayers of the mantle?
The mantle is divided into two portions; upper mantle and lower mantle. Upper mantle is further sub-divided into two layers; lithosphere and asthenosphere.
Is the asthenosphere part of the mantle?
Asthenosphere, zone of Earth’s mantle lying beneath the lithosphere and believed to be much hotter and more fluid than the lithosphere. The asthenosphere extends from about 100 km (60 miles) to about 700 km (450 miles) below Earth’s surface.