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  • 火成岩分类

    Devil's Tower in Wyoming, showcasing hexagonal columns formed by cooling igneous rock.

     

    Is this igneous rock intrusive or extrusive?
    ::这是侵扰性岩石还是扩张性岩石?

    You can't really tell from this view. A close up view would show small crystals in a dark colored  . This indicates rapid cooling from a basalt  lava . The most interesting feature you can see are the hexagonal "posts." For them to form, cooling must not have been too rapid. This amazing feature is Devil's Tower in Wyoming.
    ::您无法从这个视图中辨别。 近距离的视图会显示暗色中的小晶体。 这表明岩浆会迅速冷却。 最有趣的特征是六边形的“ 柱子 ” 。 要形成它们, 冷却一定不会太快。 这个惊人的特征是怀俄明的魔鬼塔 。

    Igneous Rock Classification
    ::冰岩分类

     are classified by composition and texture. The composition can be  felsic ,  intermediate ,  mafic , or  ultramafic . The composition depends on the   the rock includes. A felsic rock will contain felsic minerals.
    ::其构成可以是 felsic、 中间、 mafic 或 extramafic 。 其构成取决于包括这些岩石在内的岩石。 一种felsic 岩石将含有 felsic 矿物 。

    The mineral compositions are listed in  Table   . The table includes examples of minerals.
    ::矿物组成情况列于表......。 该表包括矿物的例子。

    Composition Color Density Minerals
    Felsic Light Low Quartz, orthoclase feldspar
    Intermediate Intermediate Intermediate Plagioclase feldspar, biotite, amphibole
    Mafic Dark High Olivine, pyroxene
    Ultramafic Very dark Very high Olivine

    Texture indicates how the  magma  cooled. Magma that cools rapidly has small or no visible crystals. Magma that cools slowly has large crystals; reference  Table    for the type of rock, the amount of silica it has, and examples.
    ::表示岩浆如何冷却。 快速冷却的岩浆有小晶体或没有可见晶体。 慢冷的岩浆有大晶体; 岩石类型的参考表格、 其硅含量, 以及示例 。

    Examples of igneous rocks showing different textures and colors.

     

    Is this an intrusive or an extrusive igneous rock?
    ::这是侵扰性岩石还是极具污点的岩石?

    Comparative examples of igneous rocks: rapid and slow-cooling textures and colors.

     

    Is this an intrusive or an extrusive igneous rock?
    ::这是侵扰性岩石还是极具污点的岩石?

    Pictured above are two pairs of igneous rocks ( Figures    and  ). The first pair is two rocks that formed from a felsic magma. The rhyolite cooled rapidly, and the granite cooled slowly. The second pair is two rocks that formed from mafic magma. The basalt cooled rapidly, and the gabbro cooled slowly. The color of the rocks and sizes of the crystals are your clues. There are other rock pairs that you could find listed below ( Table   ).
    ::上面的图象是两对有色岩石(图和)。第一对岩石是两块由熔岩形成的岩石。花岗岩迅速冷却,花岗岩缓慢冷却。第二对岩石是泥浆岩浆形成的两块岩石。巴萨岩迅速冷却,加布罗岩层缓慢冷却。岩石和晶体大小的颜色就是你的线索。下面还有其他岩石对(表)可以找到。

    Type Amount of Silica Extrusive Intrusive
    Ultramafic <45% Komatiite Peridotite
    Mafic 45-52% Basalt Gabbro
    Intermediate 52-63% Andesite Diorite
    Intermediate-Felsic 63-69% Dacite Granodiorite
    Felsic >69% SiO 2 Rhyolite Granite

    Summary
    ::摘要

    • Igneous rocks are classified first by composition. Categories go from from felsic to ultramafic. Color can indicate composition.
      ::岩浆岩首先按成分进行分类,类别从felsic到超层岩浆。颜色可以显示成分。
    • Texture is second when classifying igneous rocks. Texture indicates how a rock cooled.
      ::在对有色岩石进行分类时,纹理是第二位的。纹理表明岩石是如何冷却的。
    • Igneous rocks are categorized in pairs. The two rocks in a pair have the same composition but different textures: gabbro-basalt, diorite-andesite, and granite-rhyolite.
      ::混凝土岩石被分为一对。两对岩石的构成相同,但有不同的纹理:加布罗-巴萨尔特、地铁和花岗岩-兰花。

    Review
    ::回顾

    1. Describe the formation of the igneous rock pair gabbro-basalt. Compare and contrast the two rock types.
      ::描述有污点的岩石对加布罗- 巴萨尔特的形成。 比较和对比这两种岩石类型 。
    1. How does the composition of a rock affect its color?
      ::岩石的构成如何影响其颜色?
    1. What are ultramafic rocks? What is their color?
      ::什么是超冻岩?

    Explore More
    ::探索更多

    Use the resource below to answer the questions that follow.
    ::利用以下资源回答以下问题。

    1. How does the rate of magma cooling affect crystal size?
      ::岩浆冷却速度如何影响晶体大小?
    1. How does an igneous rock get a glassy texture?
      ::光滑的岩石怎么会有玻璃质地?
    1. What is the name of the texture if extremely small crystals form? Where do rocks like this form?
      ::如果微小的晶体形成,纹理的名称是什么?像这样的岩石在哪里?
    1. If there is lot of water in the cooling magma what is the texture? Where might this happen?
      ::如果冷却岩浆里有大量的水 纹理是什么?
    1. What is a good example of a glassy rock? What feature does this rock have that is just like glass?
      ::玻璃岩石的好例子是什么?这块石头有什么特征,就像玻璃一样?
    1. What does felsic mean? What are the features of felsic minerals?
      ::Felsic是什么意思? Felsic 矿物的特征是什么?
    1. What does mafic mean? What are the features of mafic minerals?
      ::mafic是什么意思? mafic矿物的特征是什么?
    1. What does ultramafic magma produce? Why is this rock important? What is its main crystal?
      ::为什么这块岩石很重要?它的主要晶体是什么?
    1. How does a porphyry form?
      ::如何形成一种吸食形态?