Banded Skagit gneiss with cross-cutting dike of younger granite orthogneiss. Orthogneiss of at least two different ages makes up much of the Skagit Gneiss Complex. Some magma intruded while rocks of the Metamorphic Core Domain were being squeezed and probably folded. While the magma crystallized or soon thereafter, the squeezing (or flattening) aligned the minerals and the rock became foliated orthogneiss. Twenty million years or so later, much of the squeezing had ceased. When new magma invaded, the newly crystallized granitic rocks developed much less foliation than their predecessors.

本檔案是由Maksim從en.wikipedia轉移到維基共享資源。

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 ∙ +/−

From: http://www2.nature.nps.gov/geology/usgsnps/noca/sb9migma.html

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• (del) (cur) 23:53, 14 November 2004 . . en:User:Vsmith Vsmith ( en:User_talk:Vsmith Talk) . . 217x324 (39818 bytes) (Banded Skagit gneiss)