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  • 沉积岩的岩化作用

    Sandstone formation showing cross-bedding and vegetation on a weathered rock surface.

     

    What steps led to this rock formation?
    ::是什么导致这种岩石形成?

    What do you see? The   is a sandstone, so first there were rocks that weathered and eroded. The cross-bedding indicates that the sand was  deposited  in a dune. The sand was then buried deeply enough that it turned into rock. This concept will explore how something like sand could become a rock.
    ::你看到什么了?这是一块沙石,所以首先有一些岩石被风化和侵蚀。交叉床表明沙被沉在沙丘中。然后,沙被深埋到足以变成岩石的深处。这个概念将探索像沙子一样的东西如何成为岩石。

    Sedimentary Rock Formation
    ::沉积岩形成

    There are two main types of  :  clastic  and chemical. Clastic rocks are made of  sediments , which are sometimes called clasts. Creating rocks from sediments is called  lithification . Chemicals  precipitate  from liquid to form  chemical sedimentary rocks .
    ::有两种主要类型:单体和化学,由沉积物组成,有时称之为光合物,从沉积物中生成的岩石称为石化,化学品从液体中沉淀,形成化学沉积岩。

    Clastic Rocks
    ::冰岩岩

    Over time, deposited sediments may harden into rock. First, the sediments are  compacted . That is, they are squeezed together by the weight of sediments on top of them. Next, the sediments are  cemented  together.   fill in the spaces between the loose sediment particles. These cementing minerals come from the  water  that moves through the sediments. Sedimentary rocks that form from sediments are called “clastic rocks.“ Clastic rocks are rock fragments that are compacted and cemented together ( Figure   ).
    ::随着时间的推移,沉积的沉积物可能会硬化成岩石。 首先,沉积层是紧凑的。 也就是说, 沉积层被上面沉积物的重量压在一起。 其次, 沉积层被凝结在一起。 填满松散的沉积物颗粒之间的空隙。 这些水泥矿物来自从沉积物中流出的水。 沉积物形成的沉积层岩石被称为“ 冰川岩石 ” 。 岩浆岩是结结结为一块的岩石碎片( 图示 ) 。

    Three types of clastic rocks: conglomerate, sandstone, and mudstone, showing varying textures.

     

    Conglomerates have larger clasts than sandstone, which have larger clasts than mudstone.
    ::联合企业有比沙石更大的光彩, 沙石有比泥石更大的光彩。

    Chemical Sedimentary Rocks
    ::化学沉积岩

    Chemical sedimentary rocks form when crystals precipitate out from a liquid. The mineral halite, also called rock salt, forms this way. You can make halite! Leave a shallow dish of salt water out in the  . As the water evaporates, salt crystals form in the dish. There are other chemical sedimentary rocks, like gypsum ( Figure   ).
    ::当水晶从液体中蒸发时,化学沉积岩会形成化学沉淀石。矿物质石灰(也称为石盐)会形成这种形态。 你可以制造石灰! 将浅浅的盐水盘留在水中。 当水蒸发时, 盐晶会形成在水中。 还有其他化学沉淀石, 如石膏(图 ) 。

    Gypsum crystal exhibiting a rose-like structure, a type of chemical sedimentary rock.

     

    Gypsum, with its rose-like structure, is a chemical sedimentary rock.
    ::Gypsum具有玫瑰状结构,是一种化学沉积岩。

     

    Summary
    ::摘要

    • Compaction and cementation lead to lithification of sedimentary rocks.
      ::压缩和水泥导致沉积岩的石化。
    • Sediments are compacted by the weight of the rocks and sediments above them.
      ::沉积物由上方岩石和沉积物的重量压紧。
    • Sediments are cemented by fluids that bind sediments together.
      ::沉积物由将沉积物捆绑在一起的液体凝固。
    • Minerals precipitate to form sedimentary rocks.
      ::矿物沉积成沉积岩。

    Review
    ::回顾

    1. How does compaction lead to lithification?
      ::压实如何导致纤维化?
    1. How does cementation lead to lithification?
      ::水泥如何导致石化?
    1. How do chemical sedimentary rocks form?
      ::化学沉积岩如何形成?

    Explore More
    ::探索更多

    Use this resource to answer the questions that follow.
    ::使用此资源回答下面的问题 。

    1. What is the source of the water in this stream?
      ::这个溪流的水源是什么?
    1. What do you think a poorly sorted sediment looks like?
      ::你觉得一个分类不当的沉积物长什么样?
    1. What do you think a bimodal sediment looks like? Note that clasts is another name for a rock or rock fragment.
      ::你认为双式沉积物长什么样?请注意,光拍是岩石或岩石碎片的另一个名称。
    1. Why would a sediment become well rounded?
      ::为什么沉积物会四舍五入?
    1. What is precipitating around the clasts?
      ::是什么在摇摇欲坠的?
    1. How do the rocks stick together to undergo lithification?
      ::岩石是如何凝结在一起 接受白化的?
    1. How can rocks form at surface temperatures and pressures?
      ::岩石如何在地表温度和压力下形成?