Partial melting of asthenosphere occurs at this location (name the process AND d
ID: 804081 • Letter: P
Question
Partial melting of asthenosphere occurs at this location (name the process AND describe ill (see previous page for diagram and instructions). Igneous process, sedimentary process, elements, minerals, rocks. Let's suppose there is a basaltic magma at depth beneath the Earth's surface. Some of the minerals with highest melting point crystallize and settle to the bottom of the magma body. Is the SiO2 (silica) content of the remaining magma HIGHER or LOWER than original basaltic magma? Partial melting of the upper mantle results in initial ("primitive") melt that has the chemical composition of (circle best answer): rhyolite; peridotite; basalt; granite; limestone Which of the following processes influence changes in magma composition after initial partial melting (circle best answers (there may be more than one))?; crystal fractionation; mixing of the magma with sea water; reaction of the magma with the atmosphere; assimilation of adjacent continental crust; mixing of sea water and the magma; mixing of liquid outer core with magma for most igneous rocks on Earth, melting originally occurred (circle best answer); in the upper mantle; in contact with sea water; in the upper crust; in the middle continental crust, as port of the "jelly sandwich"; in the lowermost mantle; in the outer core; on another planetary body. What is the main reason volcanic eruptions threaten more lives today than 100 years ago? Explain how the chemistry of magma influences the explosiveness of a volcano. In your answer explain: how magma chemistry influences the physical characteristics of the magma, and how those physical characteristics influence how explosive a resulting eruption is and why, and what this ultimately means in terms of the relationship between magma chemistry and the potential explosiveness of a volcano.Explanation / Answer
1.SiO2 of the remaining magma will go on relative increasing as the the minerals of the higher melting temperature will christianize out from the melt mainly Fe- Mg rich minerals mainly Olivines, Pyroxin etc. and it’ll left out the melt richer in the Si rich melt. So the concentration of the melt will go on increasing in the SiO2 .
2. Partial melting of the primitive mantel will result in the generation of the Basaltic melt will can under go for the numerous diversified form into numerous other melt by the various diversification process. So the option C is correct.
3.The various processes that are responsible for the diversification or the change in the magma composition are-
Fractional Crystallization by the means of crystal fractionation
Volatile transport
Liquid immiscibility
Magma Mixing
Assimilation
So the option -A is correct
4.In the earth we have different tectonic setups in which we find that melting is mainly achieved in the subduction related set up in which the crust part goes bellow the mantel and due to this there is an huge amount of heat is being generated by the friction as well as due to the presence of the stored radio active elements due to this heat most of the the part of the hydrous mantle will go on melting where as the part of the crust too melt Some times it’s being aided with the adiabatic decomposability in this precesses . So the option- A.