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  • General

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  • 火成岩

    Granite formation, basalt lava flow, and igneous rock texture examples from nature.
     

    Have you seen igneous rocks in the field?
    ::你们在田里见过有污秽的岩石吗?

    Igneous   are everywhere! One of the most common igneous rocks that make up the  crust  is granite. Many  mountain  ranges are made of granite. The spectacular features of Yosemite  Valley , like Half  Dome , are granitic.   are made of igneous rocks, such as basalt. Igneous rocks are also found where you can't see them.  Oceanic crust  is mostly basalt and gabbro. The mantle is  peridotite .
    ::地壳上最常见的有色岩石之一是花岗岩。 许多山脉由花岗岩组成。 Yosemite 谷地的壮观特征,如半穹顶,都是有色岩石,如大石等。 在你看不到这些岩石的地方,也发现了有色岩石。海洋地壳大部分是粗岩石和加布罗岩。花岗岩是环状的。

    Igneous Rocks
    ::冰岩岩

    Igneous rocks form when  magma  cools and forms crystals. Magma is melted rock. What an  igneous rock  looks like is determined by two things. One is the composition of the magma. The other is how fast the magma cools. The rate of cooling determines the rock’s texture, or size of the   crystals.
    ::当岩浆冷却并形成晶体时, 岩浆会形成微弱的岩石。 岩浆是融化的岩石。 皮状的岩石长得像由两件事决定。 一是岩浆的构成,另一是岩浆冷却的速度。 冷却的速度决定了岩石的质地或晶体的大小。

    Composition
    ::组成构成构成构成构成构成构成

    Different igneous rocks contain minerals with different compositions.  Mafic  igneous rocks contain mafic minerals. Mafic minerals are dense and dark in color. They typically contain iron and magnesium; they are low in silica. Olivine and pyroxene are mafic minerals.
    ::不同发光的岩石含有不同成分的矿物。 Mafic 发光的岩石含有粗糙的矿物。 Mafic 矿物质在颜色上是稠密和暗的。它们通常含有铁和镁;在硅含量低。奥利维尼和皮质的矿物是腐烂的矿物。

    Close-up view of olivine crystals showcasing green and dark mineral compositions in igneous rock.
     
    Olivine is the green mineral, pyroxene is the black mineral.

    Felsic  igneous rocks contain felsic minerals. They typically contain aluminum and sodium; they are high in silica. Quartz and potassium feldspar are felsic minerals. Minerals and rocks with a composition in between mafic and felsic are called  intermediate .
    ::Felsic 具有皮质的岩石含有氟化矿物,通常含有铝和钠;在硅酸中含量较高。Quartz和feldspar钾是氟化矿物,介质介质介质的矿物和岩石被称为介质介质。

    Close-up of minerals in igneous rock: olivine, pyroxene, potassium feldspar, plagioclase feldspar.
     
    Potassium feldspar is the pink mineral, plagioclase feldspar is the white mineral, and quartz is the gray mineral.

     

    Summary
    ::摘要

    • Magma cools to form igneous rocks. Two factors determine what type of rock forms.
      ::岩浆冷却形成有色岩石。有两个因素决定了何种岩浆形式。
    • The composition of the magma determines if the rock is mafic, felsic, or intermediate.
      ::岩浆的构成决定了岩石是岩浆、岩浆还是中间岩浆。
    • The rate the magma cools determines the texture of the rock.
      ::以岩浆冷却的速率决定岩石的质地。

    Review
    ::回顾

    1. How does an igneous rock form?
      ::一个不光彩的岩石是怎样形成的?
    1. How do mafic and felsic minerals and rocks differ from each other?
      ::岩浆和炼油矿物和岩石之间有什么不同?
    1. What two factors determine what type of rock a magma will form?
      ::何两项因素决定岩浆将形成何种类型的岩石?