| K- and Si-Metasomatism, Mineral Transformation and Formation of Granitoids from Basic Rocks in Qooshchi Area, NW Iran. A Mineralogical Context |
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| 作者姓名： | PouranBehnia LorenceGCollins BahrainASamani |
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| 作者单位： | State Key Laboratory of Information Engineering in Surveying，Mapping & Remote Sensing，Department of Geological Sciences，California State University，Atomic Energy Organization of Iran Wuhan University，Wuhan 430079 Department of Geomatics，Geol ogical Survey of Iran，Tehran，Iran，Northridge，USA，Tehran，Iran |
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| 摘 要： | The Qooshchi area lies to northwest of Orumieh Lake in western Azerbaijan, NW Iran. A basement metamorphic complex, consisting of Precambrian schists and gneisses, has been intruded by gabbres and diorites. Granitolds are grouped into five suites according to their mineralogy, texture and exposed features. The main body, pink Qooshchi granite, and apophyse-like, myrmekite-bearing granit-oids are discussed in this paper. On the basis of field observations and microscopic studies, an intensive metasonmtism has overprinted the country rocks, especially gabbros, transforming them into a more felsic composition. A prior event of intensive deformation and cataclasis preceded the metasonmtism, al-lowing the introduction of hydrothermal fluids. K-metasonmtism converted plagiuclase into K-feldspar (microdme), myrmekite, and sodic plagioclase as Si-metasomatism replaced the ferromagnesian silicates by quartz. Apophyse-like bodies within gabbros, called leucometasomatites, are formed during this process.
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| 关 键 词： | 交代变质作用 A型花岗岩 伊朗 钾 硅 形成 岩石学 元素地球化学 Qooshchi地区 |
K-and Si-Metasomatism, Mineral Transformation and Formation of Granitoids from Basic Rocks in Qooshchi Area, NW Iran: A Mineralogical Context |
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| PouranBehnia LorenceGCollins BahrainASamani.K- and Si-Metasomatism, Mineral Transformation and Formation of Granitoids from Basic Rocks in Qooshchi Area, NW Iran. A Mineralogical Context[J].Journal of China University of Geosciences,2003,14(1):34-41. |
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| Authors: | Pouran Behnia Lorence G Collins Bahram A Samani |
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| Abstract: | The Qooshchi area lies to northwest of Orumieh Lake in western Azerb ai jan, NW Iran. A basement metamorphic complex, consisting of Precambrian schists and gneisses, has been intruded by gabbros and diorites. Granitoids are grouped into five suites according to their mineralogy, texture and exposed features. Th e main body, pink Qooshchi granite, and apophyse like, myrmekite bearing grani toids are discussed in this paper. On the basis of field observations and micros copic studies, an intensive metasomatism has overprinted the country rocks, espe cially gabbros, transforming them into a more felsic composition. A prior ev ent of intensive deformation and cataclasis preceded the metasomatism, allowing the introduction of hydrothermal fluids. K metasomatism converted plagioclase i nto K feldspar (microcline), myrmekite, and sodic plagioclase as Si metasomati sm replaced the ferromagnesian silicates by quartz. Apophyse like bodies within gabbros, called leucometasomatites, are formed during this process. |
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| Keywords: | metasomatism myrmekite A type granites Azerbaijan Iran |
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