ﺛﺎﻟﺜﺎً :اﻟﺼﺨـــﻮر اﻟﻤﺘﺤﻮﻟﺔ ٍMetamorphic Rocks ﺗﺘﻌﺮض ﺻﺨﻮر اﻟﻘﺸﺮة اﻻرﺿﯿﺔ ﺑﻔﻌﻞ ﻋﻮاﻣﻞ اﻟﺘﺤﻮل اﻟﻤﺘﻤﺜﻠﺔ ﻓﻲ اﻟﺘﻐﯿﺮ ﻓﻲ درﺟﺔ اﻟﺤﺮارة واﻟﻀﻐﻂ واﻟﻤﺤﺎﻟﯿﻞ اﻟﻨﺸﻄﺔ ﻛﯿﻤﯿﺎ ﺋﯿﺎ واﻟﻨﺎﺗﺠﺔ ﻋﻦ اﻻﻧﺸﻄﺔ اﻟﺒﺮﻛﺎﻧﯿﺔ أو ﺗﺼﺎدم اﻟﻮاح اﻟﻐﻼف اﻟﺼﺨﺮي ﻟﻠﻜﺮة اﻷرﺿﯿﺔ ﻣﻜﻮن اﻟﺼﺨﻮر اﻟﻤﺘﺤﻮﻟﺔ واﻟﺘﻲ ﺗﺘﻤﺜﻞ ﻓﻲ إﻋﺎدة ﺗﺮﺗﯿﺐ واﺗﺠﺎه اﻟﺤﺒﯿﺒﺎت اﻟﻤﻌﺪﻧﯿﺔ وﻛﺪﻟﻚ ارﺗﻔﺎع ﺷﺪة ﺗﺒﻠﺮ اﻟﺼﺨﺮ وﺻﻼﺑﺘﮫ وﻛﻤﺎ ﯾﻌﺎد اﻻﺗﺤﺎد اﻟﻜﯿﻤﯿﺎﺋﻲ ﻟﺒﻌﺾ اﻟﻤﺮﻛﺒﺎت ﺑﺎﻟﺼﺨﺮ اﻻﺻﻠﻲ. ﺣﯿﺚ ﺗﺘﻔﺎوت درﺟﺔ اﻟﺘﺤﻮل ﺑﯿﻦ أﻧﻮاع اﻟﺼﺨﻮر ،ﻓﺎﻟﺼﺨﻮر اﻟﻨﺎرﯾﺔ اﻟﻨﺎﺑﻄﺔ واﻟﺼﺨﻮر ﺳﺎﺑﻘﺔ اﻟﺘﺤﻮل اﻟﻨﺎﺷﺌﺘﯿﻦ ﻓﻲ درﺟﺎت ﺣﺮارة وﺿﻐﻂ ﻋﺎﻟﯿﯿﻦ أﻗﻞ ﺗﺎﺛﺮ ﻣﻦ اﻟﺼﺨﻮر اﻟﺮﺳﻮﺑﯿﺔ اﻟﺘﻲ ﺗﻜﻮﻧﺖ ﻓﻲ ﻇﺮوف ﺣﺮارة وﺿﻐﻂ ﻣﻨﺨﻔﻀﯿﻦ ﻓﻮق ﺳﻄﺢ اﻻرض. ﯾﻨﻘﺴﻢ اﻟﺘﺤﻮل اﻟﻲ ﻗﺴﻤﯿﻦ-: • اﻟﺘﺤﻮل اﻻﻗﻠﯿﻤﻲ Regional Metamorphism ﯾﻌﺮف ﺑﺎﻟﺘﺤﻮل اﻻﻗﻠﯿﻤﻲ ﻻﻧﮫ ﯾﺆدي اﻟﻲ ﻃﻲ وﻗﺺ ﺻﺨﻮر اﻻﻟﻮاح اﻟﻤﺘﺼﺎدﻣﺔ ﻟﻤﺴﺎﺣﺎت ﻛﺒﯿﺮة وﺗﺪل ﺗﺠﻤﻌﺎت اﻟﻤﻌﺎدن ﻋﻠﻰ درﺟﺔ اﻟﺘﺤﻮل اﻻﻗﻠﯿﻤﻲ ﻓﻤﻌﺎدن اﻟﻜﺎﻟﺴﯿﺖ واﻟﻤﺎﯾﻜﺎ واﻟﺘﻠﻚ ﺗﺪل ﻋﻠﻰ ﺗﺤﻮل أﻗﻞ ﺷﺪة ﻣﻦ ﻣﻌﺎدن اﻟﺠﺎرﻧﺖ واﻻﻣﻔﯿﺒﻮل اﻟﺘﻲ ﺗﺪل ﻋﻠﻰ اﻋﻠﻰ ﺷﺪة. • اﻟﺘﺤﻮل اﻟﺘﻤﺎﺳﻲ Contact Metamorphism ﻋﻨﺪ اﻗﺘﺤﺎم اﻟﺼﮭﯿﺮ ﺻﺨﻮر اﻟﻘﺸﺮة اﻻرﺿﯿﺔ ﯾﻔﻘﺪ ﺣﺮارﺗﮫ ﺗﺪرﯾﺠﯿﺎ ﻟﻠﺼﺨﻮر اﻟﻤﺠﺎورة واﻟﻤﻼﻣﺴﺔ اﻟﺘﻲ ﺗﺘﺎﺛﺮ ﺑﻔﻌﻞ ﺣﺮارة اﻟﺼﮭﯿﺮ اﻟﻤﻔﻘﻮدة ﻣﻜﻮﻧﺔ ﺻﺨﻮرا اﺷﺪ ﺗﺒﻠﻮر وﺗﺼﻠﺒﺎ وﺗﺴﻤﻲ ھﺪه ﻓﻲ اﻟﻐﺎﻟﺐ ﺑﺼﺨﻮر اﻟﮭﻮرﻧﻔﻠﺲ.
ﺗﺼﻨﯿﻒ اﻟﺼﺨﻮر اﻟﻤﺘﺤﻮﻟﺔ Classification of Metamorphic Rocks اﻟﺼﺨﻮر اﻟﻤﺘﺤﻮﻟﺔ اﻟﻤﺘﻮرﻗﺔ :Foliated rocks ﺗﺘﺮﺗﺐ اﻟﻤﻌﺎدن ﻋﻠﻰ ھﯿﺌﺔ رﻗﺎﺋﻖ ﺑﻄﺮﯾﻘﺔ ﻣﺘﻮازﯾﺔ او ﺷﺒﮫ ﻣﺘﻮازﯾﺔ ﺗﻨﻔﺼﻢ ﻋﺒﺮ ھﺪه اﻟﻤﺴﺘﻮﯾﺎت ﺗﺘﻮاﺟﺪ ھﺪه اﻟﺨﺎﺻﯿﺔ ﻣﻊ ﺗﻜﻮﯾﻦ اﻟﺴﻼﺳﻞ اﻟﺠﺒﻠﯿﺔ.
اﻟﺼﺨﻮر اﻟﻤﺘﺤﻮﻟﺔ ﻋﺪﯾﻤﺔ اﻟﻤﺘﻮرﻗﺔ :Non Foliated rocks ھﺪا اﻟﻨﻮع ﻻﯾﺤﺘﻮي ﻋﻠﻰ ﻣﻌﺎدن ﻣﺘﺠﮭﮫ وﺗﺘﻮاﺟﺪ ﻋﺎدة ﻣﺠﺎورة ﻟﺘﺪاﺧﻼت اﻟﺼﺨﻮر اﻟﻨﺎرﯾﺔ اي ان ﯾﺘﻜﻮن ھﺪا اﻟﻨﻮع ﻧﺘﯿﺠﺔ اﻟﺘﻤﺎس ﺣﯿﺚ ﺗﻨﻤﻮ ﺑﻠﻮرات ھﺪه اﻻﻧﻮاع ﻣﻦ اﻟﺼﺨﻮر اﻟﺮﺳﻮﺑﯿﺔ وﺗﺰداد ﺻﻼﺑﺘﮭﺎ ﻣﺘﻞ ﺗﺤﻮل اﻟﺤﺠﺮ اﻟﺠﯿﺮي اﻟﻰ رﺧﺎم واﻟﺮﻣﻞ اﻟﻰ ﻛﻮرﺗﺰاﯾﺖ.
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Type of Metamorphic rocks- Amphibolite
Type of Metamorphic rocks- garnet-schist
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Type of Metamorphic rocks- chlorite-schist
Type of Metamorphic rocks- muscovite-schist
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Type of Metamorphic rocks- hornfels
Type of Metamorphic rocks- marble
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Type of Metamorphic rocks- quartzite
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Type of Metamorphic rocks- phyllite
Type of Metamorphic rocks- Green Red Black slate
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