GEO 303 Chapter Notes - Chapter 9: Gneiss, Mica, Muscovite

24 views1 pages
10 May 2016
Geo Chapter 9 Notes:
oMetamorphism: to transform
A rock that was once sedimentary or igneous that has
transformed significantly enough to justify calling it a new rock
High pressure and high temperature are the factors that
warrant a rock being metamorphic
Sheer stress: force that is applied to the rock along certain
directions only
Role of Water in Metamorphism
oDuring metamorphism, water is dissolved within the rock
Types of Metamorphism
oDynamic metamorphism: rocks on either side are forced past one
another for great distances, they are crushed and smeared
oContact metamorphism: seen along the margins of some igneous
intrusions, heat and fluid (mostly H20) escaping from the hot magma
can penetrate the surrounding, or host rock
High temperature is the chief ingredient
oRegional metamorphism: sheer stress, high pressure, and high
temperature are all likely to be important here
Affects a very large areas in which rocks that formed near the
surface have been brought down to great depth where they
recrystallize, attaining equilibrium with the condition of the
new environment
Common Metamorphic rocks
oSlate: tiny parallel wisps of muscovite mica appear, which enables the
rock to split into thin, flat sided plates characteristic of slate
oMetamorphic foliation: the theme of parallel layering of crystal faces
is carried out in most metamorphic rocks
oSchist: coarse grained rock
oSchist and gneiss are convenient terms to describe appearance
without regard to origin
Ancient Regional Metamorphism: A classic study
oIsograds: mark zones of equal grade or intensity of metamorphism
oMetamorphic rocks originate when igneous, sedimentary, or
preexisting Metamorphic rocks are recrystallized in the sold state,
transformed into a new set of minerals which are stable under
conditions of elevated temperature and pressure
oSheer stress and traces of H20 increase the rate and degree of
oRegional metamorphism affects rocks that formed near the surface,
brought to great depth in the earth
find more resources at
find more resources at
Unlock document

This preview shows half of the first page of the document.
Unlock all 1 pages and 3 million more documents.

Already have an account? Log in

Get OneClass Notes+

Unlimited access to class notes and textbook notes.

YearlyBest Value
75% OFF
$8 USD/m
$30 USD/m
You will be charged $96 USD upfront and auto renewed at the end of each cycle. You may cancel anytime under Payment Settings. For more information, see our Terms and Privacy.
Payments are encrypted using 256-bit SSL. Powered by Stripe.