GSU GEOL 1122K - CHAPTER 7 QUIZ (16 pages)

Previewing pages 1, 2, 3, 4, 5 of 16 page document View the full content.
View Full Document

CHAPTER 7 QUIZ



Previewing pages 1, 2, 3, 4, 5 of actual document.

View the full content.
View Full Document
View Full Document

CHAPTER 7 QUIZ

148 views


Pages:
16
School:
Georgia State University
Course:
Geol 1122k - Introductory Geosciences Ii

Unformatted text preview:

CHAPTER 7 READING QUIZ According to this metamorphic facies graph which of the following statements is TRUE Blueschist facies rocks form at high pressures and low temperatures Hornfels facies rocks form in a narrow range of temperature conditions 400 C Greenschist facies form at depths greater than 35 km The highest pressure facies indicated on this graph is the hornfels facies FEEDBACK Blueschist facies rocks do form under high pressure but low temperature conditions However hornfels facies rocks form under a wide range of temperatures greenschist facies form at depths less than 35 km and the highest pressure facies on this diagram is the eclogite facies Choose the listing that shows the rocks in increasing degrees of metamorphism i e from lower to higher grade migmatite metaconglomerate gneiss metaconglomerate gneiss migmatite gneiss metaconglomerate migmatite gneiss migmatite metaconglomerate FEEDBACK Metaconglomerate is barely metamorphosed see Fig 7 5c higher heat changes the rock into a gneiss Fig 7 6a and migmatite has been so strongly heated some rock has melted and become new igneous rock Identify the FALSE statement Hydrothermal fluids may consist of hot water gases or supercritical fluids can accelerate metamorphic reactions change a rock s chemical composition a process known as exhumation can be derived from groundwater or magma or can be the product of metamorphic reactions FEEDBACK They do change the chemical composition but the process is known as metasomatism Exhumation means that deeply buried rocks can eventually be exposed at Earth s surface Metamorphic aureoles typically contain nonfoliated rock like hornfels because they form adjacent to an intruding pluton which provides heat for metamorphism they form as a consequence of shearing without a subsequent change in temperature or pressure compressional forces associated with mountain building provide the necessary pressure to create hornfels they form at shallow burial depths less than 8 km FEEDBACK Aureoles typically form around igneous intrusions by contact thermal metamorphism The addition of heat but little pressure produces nonfoliated metamorphic rocks Quartzite is basically a solid mass of interlocking quartz grains breaks around the separate grains of quartz that make it up is always either white or gray always shows strong compositional banding FEEDBACK Quartzite is a nonfoliated no banding metamorphic rock that may be white gray purple or green it breaks across not around its component grains Recrystallization occurs when rocks become warm enough that they behave like soft plastic results in the growth of new minerals that differ from the protolith changes the texture shape and size of the grains is a process by which grains push against one another creating dissolution FEEDBACK The recrystallization process doesn t change the identity or chemical composition of the mineral it just produces larger crystals of the mineral so it changes the texture of the grains Plastic



View Full Document

Access the best Study Guides, Lecture Notes and Practice Exams

Loading Unlocking...
Login

Join to view CHAPTER 7 QUIZ and access 3M+ class-specific study document.

or
We will never post anything without your permission.
Don't have an account?
Sign Up

Join to view CHAPTER 7 QUIZ and access 3M+ class-specific study document.

or

By creating an account you agree to our Privacy Policy and Terms Of Use

Already a member?