2015考研英语阅读集中练：isolated volcanic activity

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考研英语阅读水平的提高重在练习，多练才能够增加词汇量，提升对语法语义的把握，才能够更容易的理解和总结文章中心主旨。正所谓熟能生巧，就是这个道理。十一刚过，后续复习任务依然很重，新东方在线小编希望考生能够继续努力，多读多练。下面分享英语阅读集中练篇章，望考生认真阅读。
    2015考研英语阅读集中练：isolated volcanic activity
   
    Scattered around the globe are more than 100 small regions of isolated
volcanic activity known to geologists as hot spots. Unlike most of the world’s
volcanoes, they are not always found at the boundaries of the great drifting
plates that make up the earth’s surface; on the contrary, many of them lie deep
in the interior of a plate. Most of the hot spots move only slowly, and in some
cases the movement of the plates past them has left trails of dead volcanoes.
The hot spots and their volcanic trails are milestones that mark the passage of
the plates.
    That the plates are moving is not beyond dispute. Africa and South America,
for example, are moving away from each other as new material is injected into
the sea floor between them. The complementary coastlines and certain geological
features that seem to span the ocean are reminders of where the two continents
were once joined. The relative motion of the plates carrying these continents
has been constructed in detail, but the motion of one plate with respect to
another cannot readily be translated into motion with respect to the earth’s
interior. It is not possible to determine whether both continents are moving in
opposite directions or whether one continent is stationary and the other is
drifting away from it. Hot spots, anchored in the deeper layers of the earth,
provide the measuring instruments needed to resolve the question. From an
analysis of the hot spot population it appears that the African plate is
stationary and that it has not moved during the past 30 million years.
    The significance of hot spots is not confined to their role as a frame of
reference. It now appears that they also have an important influence on the
geophysical processes that propel the plates across the globe. When a
continental plate come to rest over a hot spot, the material rising from deeper
layer creates a broad dome. As the dome grows, it develops seed
fissures(cracks); in at least a few cases the continent may break entirely along
some of these fissures, so that the hot spot initiates the formation of a new
ocean. Thus just as earlier theories have explained the mobility of the
continents, so hot spots may explain their mutability (inconstancy).
      温馨提示：10月10日，本周五是考研正式报名开始，希望广大应往届考生提前做好准备。
   
   

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