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modern Appalachians expose zones of low to high-gradedynamothermally-metamorphosed rock for distances that may be thousands of kmin length and hundreds of km in width●False28.Dissolved ions freed during the process of metasomatism can precipitate to formmineral-?lled cracks called veins.—hydrothermal 틃uids dissolve the ions, which are then free to relocate eitherin veins in the earth or on its surface29.Contact metamorphism occurs when:30.Which process would you most expect during hydrothermal metamorphism near amid-ocean ridge?●Foliation●Pressure solution●Dynamothermal metamorphism✓Metasomatism —metasomatism is the alteration of a rock’s composition due to theinteraction with very hot aqueous (water) solution., i.e. hydrothermal solution●Dynamic metamorphismCHAPTER 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 scaleThere’s a three-step di뮎erence between a 4.2 and 7.2 quake. The di뮎erence in groundshaking (amplitude) for this would be 10 x 10 x 10 = 1,000. The energy di뮎erence would beapproximately 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 inheight as it approaches a shallowing shore
●Is a special kind of tidal wave caused by gravitational attraction of the Sun, not theMoon.Feedback/Reference: Tsunamis are caused by volcanic or seismic activity or by undersealandslides, can get tens of meters high, and can cross entire ocean basins.