此geology图片可使用矢量图形重新创建为SVG文件。这具有很多好处；更多信息请参见共享资源:待清理媒体。如果存在此图片的SVG格式，请将其上传，然后将此模板替换为{{vector version available|新图片名称}}。 建议您将SVG命名为“North america craton nps.svg”，这样在使用Vector version available（或Vva）模板时就不需要填写新图片名称参数。

North American craton.

The brown area shows the part of the North American continent that has been stable for over 600 million years. This region is made up of a basement older Precambrian metamorphic and igneous rock that is mostly covered by a relatively thin cover of younger sedimentary rock. Geologists call these long-stable continental cores cratons.

The green area on the illustration shows new continental material that was added relatively recently, within the last 600 million years or so. Continents can grow when two plates collide, welding, or accreting, the two pieces together. Continents also grow when oceanic crust is scraped off oceanic plates as they sink in subduction zones.

The purple area fringing the stable continental core is made up of older Precambrian basement that was deformed during plate collisions that occurred within the last 600 million years. The force of collision produced great folds and faults that sometimes penetrated deep into the continental interior. Where the crust was uplifted, these folds and faults are exposed at the surface, allowing geologists to piece together the ancient history of our continent.

http://www2.nature.nps.gov/geology/usgsnps/pltec/nacraton512x599.gif

Source: English Wikipedia, original upload 15 April 2005 by SEWilco

本图片在美国属于公有领域，因为其只包含最初来自美国内政部下属机构美国地质调查局的材料。更多信息请参见USGS官方版权方针。 Bahasa Indonesia ∙ català ∙ čeština ∙ Deutsch ∙ eesti ∙ English ∙ español ∙ français ∙ galego ∙ italiano ∙ Nederlands ∙ português ∙ polski ∙ sicilianu ∙ suomi ∙ Tiếng Việt ∙ Türkçe ∙ български ∙ македонски ∙ русский ∙ മലയാളം ∙ 한국어 ∙ 日本語 ∙ 中文 ∙ 中文（简体） ∙ 中文（繁體） ∙ العربية ∙ فارسی ∙ +/−