Modern appalachians expose zones of low to high grade

modern Appalachians expose zones of low to high-grade
dynamothermally-metamorphosed rock for distances that may be thousands of km
in length and hundreds of km in width
● False
28.Dissolved ions freed during the process of metasomatism can precipitate to form
mineral-?lled cracks called veins.
—hydrothermal 틃uids dissolve the ions, which are then free to relocate either
in veins in the earth or on its surface
29. Contact metamorphism occurs when:
30. Which process would you most expect during hydrothermal metamorphism near a
mid-ocean ridge?
● Foliation
● Pressure solution
● Dynamothermal metamorphism
✓ Metasomatism —metasomatism is the alteration of a rock’s composition due to the
interaction with very hot aqueous (water) solution., i.e. hydrothermal solution
● Dynamic metamorphism
CHAPTER 8 QUIZ
(1) A m
w
magnitude earthquake
● would be so large that a quake this size would occur only once a century
● would produce surface waves 10,000 times the amplitude of a 4.2 quake
✓ would release approximately 33,000 times the energy of a 4.2 quake
● is one of the largest possible and is classed as a great quake
● would produce a reading of about XII on the Mercalli intensity scale
There’s a three-step di뮎erence between a 4.2 and 7.2 quake. The di뮎erence in ground
shaking (amplitude) for this would be 10 x 10 x 10 = 1,000. The energy di뮎erence would be
approximately 32 x 32 x 32, which is almost 33,000.
(2)A tsunami
● Is dangerous near its source but dies out within about 200 miles
● Can get big but never larger than 30 feet high
✓ May be just a low and very broad wave at sea but both slows in speed and grows in
height as it approaches a shallowing shore

● Is a special kind of tidal wave caused by gravitational attraction of the Sun, not the
Moon.
Feedback/Reference: Tsunamis are caused by volcanic or seismic activity or by undersea
landslides, can get tens of meters high, and can cross entire ocean basins.