gwd7-Q22 形成火山的两个机理

chasedreampt

大家帮帮忙，能不能帮我分析一下，这种题材的阅读，应该怎么分析，怎么做？

每次一涉及到有关地理类的文章，就傻眼了，总是做不好！这篇文章看了好几次了，

文章的脉络还是没有搞清楚！

帮我分析一下应该怎么对付这类文章，以及怎样做这种题

谢谢大家！

 GWD-7-Q22 to Q25形成火山的两个机理

      Earth’s surface consists of rigid

      plates that are constantly shifting and

      jostling one another.  Plate movements

Line     are the surface expressions of motions

  (5)    in the mantle—the thick shell of rock

that lies between Earth’s crust and its

metallic core.  Although the hot rock of

the mantle is a solid, under the tre-

mendous pressure of the crust and

 (10)    overlying rock of the mantle, it flows like

a viscous liquid.  The mantle’s motions,

analogous to those in a pot of boiling

water, cool the mantle by carrying hot

material to the surface and returning

 (15)    cooler material to the depths.  When

the edge of one plate bends under

another and its cooler material is con-

sumed in the mantle, volcanic activity

occurs as molten lava rises from the

 (20)    downgoing plate and erupts through the

      overlying one.

            Most volcanoes occur at plate

boundaries.  However, certain “mis-

placed” volcanoes far from plate

 (25)    edges result from a second, indepen-

dent mechanism that cools the deep

interior of Earth.  Because of its prox-

imity to Earth’s core, the rock at the

base of the mantle is much hotter than

 (30)    rock in the upper mantle.  The hotter the

mantle rock is, the less it resists flow-

ing.  Reservoirs of this hot rock collect

      in the base of the mantle.  When a

reservoir is sufficiently large, a sphere

 (35)
                of this hot rock forces its way up

through the upper mantle to Earth’s

surface, creating a broad bulge in the

topography.  The “mantle plume” thus

     formed, once established, continues to

 (40)   channel hot material from the mantle

base until the reservoir is emptied.

The surface mark of an established

plume is a hot spot—an isolated

region of volcanoes and uplifted terrain

 (45)    located far from the edge of a surface

plate.  Because the source of a hot

spot remains fixed while a surface

plate moves over it, over a long period

of time an active plume creates a chain

 (50)    of volcanoes or volcanic islands, a

track marking the position of the plume

relative to the moving plate.  The natural

history of the Hawaiian island chain

clearly shows the movement of the

Pacific plate over a fixed plume.

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Q22:

The passage is primarily concerned with discussing

          

1. the composition of Earth’s mantle

2. how the Hawaiian Islands were created

3. what causes Earth’s surface plates to move

4. two different mechanisms by which volcanoes are formed

5. why most volcanoes occur at plate boundaries

Answer:   D

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Q23:

It can be inferred from the passage that a chain of volcanoes created by a mantle plume would most likely be characterized by

          

1. a curved outline

2. constituent volcanoes that differ from each other in age

3. occurrence near a plate boundary where one plate bends under another

4. appearance near many other volcanic chains

5. rocks with a wide range of chemical composition

Answer:   B

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Q24:

The author’s reference to the Hawaiian Islands serves primarily to

          

1. provide an example of a type of volcanic activity that does not occur elsewhere

2. identify the evidence initially used to establish that the Pacific plate moves

3. call into question a theory about the source of the volcanoes that created the Hawaiian Islands

4. illustrate the distance from plate edges at which volcanoes typically appear

5. provide an example of how mantle plumes manifest themselves on Earth’s surface

Answer:   E

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Q25:

According to the passage, a hot spot on Earth’s surface is an indication of which of the following?

 

1. An untapped reservoir of hot rock in the base of the mantle

2. Volcanic activity at the edge of a plate

3. Solid mantle rock under tremendous pressure

4. The occurrence of a phenomenon unique to the Pacific plate

5. A plume of hot mantle rock originating near Earth’s core

Answer:   E

qidandan1103

顶哇！我也理不清思路，求教大牛牛

alisaxu

Earth’s surface consists of rigid
    plates that are constantly shifting and
    jostling one another.  late movements
Line    are the surface expressions of motions
 (5)    in the mantle—the thick shell of rock
that lies between Earth’s crust and its
metallic core.  Although the hot rock of
the mantle is a solid, under the tre-
mendous pressure of the crust and
(10)    overlying rock of the mantle, it flows like
a viscous liquid.  The mantle’s motions,
analogous to those in a pot of boiling
water, cool the mantle by carrying hot
material to the surface and returning
(15)    cooler material to the depths.  When
the edge of one plate bends under
another and its cooler material is con-
sumed in the mantle, volcanic activity 第一段描述了半天plate和liquid hot rock的事，最后这些落在volcanic activity上，是为了将这个东东的mechanism
occurs as molten lava rises from the
(20)    downgoing plate and erupts through the
    overlying one.
          Most volcanoes occur at plate
boundaries. 对上一段的volcano总结，就是那种形成于boundary的 However, certain “mis-
placed” volcanoes far from plate
(25)    edges result from a second, indepen-
dent mechanism that cools the deep
interior of Earth.  第二种volcano，在前不着村后不着店的地方形成的。Because of its prox-
imity to Earth’s core, the rock at the
base of the mantle is much hotter than
(30)    rock in the upper mantle.  The hotter the
mantle rock is, the less it resists flow-
ing.  Reservoirs of this hot rock collect
    in the base of the mantle.  When a
reservoir is sufficiently large, a sphere
(35) of this hot rock forces its way up
through the upper mantle to Earth’s
surface, creating a broad bulge in the
topography.  The “mantle plume” thus
    formed, once established, continues to
(40)    channel hot material from the mantle
base until the reservoir is emptied.
The surface mark of an established
plume is a hot spot—an isolated
region of volcanoes and uplifted terrain
(45)    located far from the edge of a surface
plate.  Because the source of a hot
spot remains fixed while a surface
plate moves over it, over a long period
of time an active plume creates a chain
(50)    of volcanoes or volcanic islands, a
track marking the position of the plume
relative to the moving plate.  The natural
history of the Hawaiian island chain
clearly shows the movement of the
Pacific plate over a fixed plume.
注意第二段开头啊，这个文的结构都在这一句话上了，承上启下了
我总结的结构哈
plate下面有liquid rock——plate一撞liquid rock出来——volcano1
地球上还有volcano2，与1不同——地底下core的地方有大池装hot rock——压力大，rock出来——volcano2——举例H就是这一种，有特征blabla
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Q22:
The passage is primarily concerned with discussing
        
A.    the composition of Earth’s mantle
B.    how the Hawaiian Islands were created
C.    what causes Earth’s surface plates to move
D.    two different mechanisms by which volcanoes are formed
E.    why most volcanoes occur at plate boundaries
Answer:   D
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Q23:
It can be inferred from the passage that a chain of volcanoes created by a mantle plume would most likely be characterized by
         问第二段的那种
A.    a curved outline 米有提
B.    constituent volcanoes that differ from each other in age
C.    occurrence near a plate boundary where one plate bends under another 第一段的那种
D.    appearance near many other volcanic chains 第二段一直用单数的火山描述，可想和many是不搭边的
E.    rocks with a wide range of chemical composition 也米有
Answer:   B
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Q24:
The author’s reference to the Hawaiian Islands serves primarily to
        
A.    provide an example of a type of volcanic activity that does not occur elsewhere
B.    identify the evidence initially used to establish that the Pacific plate moves 脱离主题啦
C.    call into question a theory about the source of the volcanoes that created the Hawaiian Islands 那里有question啊
D.    illustrate the distance from plate edges at which volcanoes typically appear   distance不是文章重点吧,这个例子也没提
E.    provide an example of how mantle plumes manifest themselves on Earth’s surface第二段讲第二种火山，最后用Hawaiian举例
Answer:   E
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Q25:
According to the passage, a hot spot on Earth’s surface is an indication of which of the following?

A.    An untapped reservoir of hot rock in the base of the mantle 已经是hot spot了，就是tapped了，我错选过这个
B.    Volcanic activity at the edge of a plate
C.    Solid mantle rock under tremendous pressure
D.    The occurrence of a phenomenon unique to the Pacific plate
E.    A plume of hot mantle rock originating near Earth’s core
Answer:   E

alisaxu

楼主凑合看，我阅读也不好……

jinyueyue

看这里 有很多NN的讨论
http://forum.chasedream.com/GMAT_RC/thread-59497-2-1.html