In one model of Earth’s formation, the earth’s crust and mantle were originally
ID: 298456 • Letter: I
Question
In one model of Earth’s formation, the earth’s crust and mantle were originally composed completely of peridotite (ultramafic igneous rock). Explain in detail four processes that created the earth’s crust and transformed the it into the diversity of rock types present in the crust (both continental and oceanic) today. a. Discuss the igneous fractionation process related to melting. What sequence and characteristics govern this process? Where in Earth does this fractionation presently occur (oceanic crust, continental crust, mantle)? In what plate tectonic environment(s) does this process occur? What types of rock can be produced via this process alone? b. Discuss the igneous fractionation process related to crystallization. What sequence and characteristics govern this process? Where in earth does this fractionation typically occur (oceanic crust, continental crust, mantle)? In what plate tectonic environment(s) does this process occur? How does crustal thickness impact the likelihood and extent of this process? What types of rock can be produced via this process alone? c. Discuss earth surface processes and how they act on areas of differential elevation. What types of processes might alter exposed rocks at the surface? How might those types of alteration change the original materials? What types of locations might accumulate the products of those alteration processes, and why? What new types of rocks can be produced via these processes? List and explain at least two different rocks that form via different processes at Earth’s surface as examples. d. Discuss deformation and metamorphism processes in Earth environments and how they impact the diversity of rocks found. Name and explain at least three environments for metamorphism, including the process by which alteration occurs and the type of alteration that would be produced there. What new types of rocks can be produced via these processes, and what is their relationship to the original rock type? List and explain at least two protolith-metamorphic rock pairs and describe how metamorphism altered the original rock. e. Speculate on how long this diversification process might have taken, given what you know about the rate of plate movement and the factors that determine this rate.
Explanation / Answer
1)a) Igneous rocks are formed from the cristallization and fractionation of magma, while cooling or melting.They include two types : They are Volcanic or extrusive and Intrusive or plutonic
Volcanic or extrusive : Igneous rocks are formed when the magma cools and cristallizes at the surface of the earth.
Intrusive or plutonic : Igneous rocks are formed by the cooling at the depth of the earth.
It forms in the mantle and onj the earth's crust.
It forms in the subduction zone of the convention plate boundary.ex :Gabbro and basalt
b)Fractionation isthe splitting of anoriginal magma or rock into 2 fractions.
1)Mafic rich on Bowen's reaction series.
2)Felsic
As crystallization may be occurs due to differentiation.Thus in Igneous rocks concentrations of basic minerals may occur near the margins and acidic minerals may segregate inthe central part.It occurs at the convection boundary at subduction zone .
It occurs at the mantle
Bowen's series is a sequence that governs the process.
types of rocks formed are Olivine,pyroxene.
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.