بررسی رخداد آنالسیم در تفریت‌های رشته کوه بزقوش، شمال میانه، شمال غرب ایران

نوع مقاله : علمی -پژوهشی

نویسندگان

1 دانشجوی دکتری زمین شناسی، دانشکده علوم زمین، دانشگاه شهید بهشتی

2 دانشیار دانشکده علوم زمین، دانشگاه شهید بهشتی

3 دانشیار سازمان زمین شناسی و اکتشافات معدنی کشور

چکیده

سنگ­های آتشفشانی با ترکیب تفریتی و فونوتفریتی با سن ائوسن بالایی در رشته کوه بزقوش، شمال غرب ایران گسترش قابل ملاحظه­ای دارند. این سنگ­های آتشفشانی هم به صورت گدازه­هایی با حجم زیاد که عمدتاً در قسمت شمالی رشته کوه بزقوش قرار گرفته­اند و با یک روند شرقی-غربی بر روی آندزیت­های مگاپورفیری ائوسن میانی قرار گرفته اند، دیده می­شوند و هم به صورت لنزهایی کوچک در بین سنگ­های ولکانی کلاستیکی جای گرفته­اند. بافت این سنگ­ها پورفیری بوده و کانی­های تشکیل دهنده شامل کلینوپیروکسن، پلاژیوکلاز، آلکالی فلدسپار، آنالسیم، الیوین و کمی لوسیت در یک زمینه شیشه­ای تا دانه­ریز می­باشند. آنالسیم در این سنگ­ها عمدتاً ایزوتروپ بوده و به صورت اجزای ریز کمتر از یک میلی­متر تا درشت بلورهایی به اندازه 1 سانتی­متر دیده می­شود. غنی شدگی سنگ­های آنالسیم­دار منطقه در Sr، عدم حضور کانی­های آبدار مثل آمفیبول و بیوتیت در سنگ­های مورد مطالعه، فقدان پیروکسن­های سدیم­دار، ترکیب هموژن بلورهای آنالسیم و وجود ترک­های نامنظم در سطح و اطراف بلور آنالسیم بیانگر این است که آنالسیم­های موجود در سنگ­های آتشفشانی رشته کوه بزقوش از تبادل یونی لوسیت­های اولیه در حین سرد شدن ماگما و یا در زمان انجماد ماگما به وجود آمده ­اند. AbstractVolcanic rocks of upper Eocene age with tephritic to phono-tephritic composition are widespread in the Bozghush Mountains, NW of Iran.These volcanic rocks are occur both as lava flowd above a megaporphyritic andesite (middle Eocene age?) as well as small lenses within the volcaniclastic rocks. The rocks are porphyritic in texture and consist of phenocrysts of pyroxene, plagioclase, alkali feldspar, analcime, olivin, apatite and minor leucite in a fine-grained and glassy matrix. The analcime in these rocks occurs as an isotropic mineral 0.5 mm to 1 cm in diameter. Enrichment of the studied rocks in Sr, the absence of hydrous primary igneous minerals such as amphibole or biotite, lack of Na-pyroxene, the homogenous nature of the analcime and irregular cracks in the analcime indicate that the analcime crystals in volcanic rocks of the Bozghush Mountains formed by ion-exchange pseudomorphous replacement of primary leucite either during cooling and crystallization, or shortly afterwards. Keywords: Eocene, Analcime, Azerbaijan, Bozghush, Tephrite. 

کلیدواژه‌ها

عنوان مقاله [English]

On the occurrence of analcime in the tephritic rocks in the Bozghush Mountains, north of Miyaneh, northwest of Iran

چکیده [English]

Volcanic rocks of upper Eocene age with tephritic to phono-tephritic composition are widespread in the Bozghush Mountains, NW of Iran.These volcanic rocks are occur both as lava flowd above a megaporphyritic andesite (middle Eocene age?) as well as small lenses within the volcaniclastic rocks. The rocks are porphyritic in texture and consist of phenocrysts of pyroxene, plagioclase, alkali feldspar, analcime, olivin, apatite and minor leucite in a fine-grained and glassy matrix. The analcime in these rocks occurs as an isotropic mineral 0.5 mm to 1 cm in diameter. Enrichment of the studied rocks in Sr, the absence of hydrous primary igneous minerals such as amphibole or biotite, lack of Na-pyroxene, the homogenous nature of the analcime and irregular cracks in the analcime indicate that the analcime crystals in volcanic rocks of the Bozghush Mountains formed by ion-exchange pseudomorphous replacement of primary leucite either during cooling and crystallization, or shortly afterwards.

کلیدواژه‌ها [English]

  • Eocene
  • Analcime
  • Azerbaijan
  • Bozghush
  • Tephrite

مراجع

  1. -خاتمیان اسکویی، م. و قنبرپور، ر.، 1386. سنتز و شناسایی کمپلکس VO(salen) در منافذ زئولیت، مجله بلورشناسی و کانی‌شناسی ایران، شماره 2، ص 42-65.
  2. -خرامش، م.، طوطی، ف.، برقی، م. ع. و بدیعی، ع.، 1388. تغییر فاز کلینوپتیلولیت طبیعی به فیلیپسیت در حضور آبگون‌های قلیایی، مجله بلور شناسی و کانی شناسی ایران، شماره 1، ص 95-102.
  3. -مقدمی، ا.، 1390. بررسی ژئوشیمیایی دگرسانی زئولیتی در سنگ‌های ولکانیکی منطقه کجل، شمال غرب هشتجین، استان اردبیل، پایان‌نامه کارشناسی‌ارشد زمین شناسی، دانشگاه تبریز.
  4. -هاشم امامی، م.،1371. نقشه زمین شناسی 100000/1 سراب، برگه شماره 5565، سازمان زمین شناسی و اکتشافات معدنی کشور، تهران، ایران.
  5. -هاشم امامی، م.، 1371. نقشه زمین شناسی 100000/1 قره چمن، برگه شماره 5564، سازمان زمین شناسی و اکتشافات معدنی کشور، تهران، ایران.
  6. -Aftabi, A. and Atapour, H., 2000. Regional aspects of shoshonitic volcanism in Iran, Episodes, v. 23, p. 119-125.
  7. -Aghanabati, A., 1995. Bam geological quadrangle map and explanatory text: Geological Society of Iran, Tehran, Iran.
  8. -Amidi, S.M., Emami, M.H. and Michel, R., 1984. Alkaline character of Eocene volcanism in the Middle part of Central Iran and its geodynamic situation: Geology, Rund, v. 73, p. 917-932.
  9. -Amidi, S.M. and Michel, R., 1985. Cenozoic magmatism of the Surk area (Central Iran): stratigraphy, petrography, geochemistry and their geodynamic implications: Geologie Alpine, v. 61, p. 1-17.
  10. -Annells, R.N., Arthurton, R.S., Bazley, R.A. and Davies, R.G., 1975. Explanatory text of the Qazvin and Rasht Quadrangles Map: Geological Survey of Iran, Tehran.
  11. -Boettcher, A.L. and Wyllie, P. J., 1969. Phase relationships in the sysrem NaAlSiO4-SiO2-H2O to 35 kilobars pressure: American Journal of Science, v. 267, p. 875-909.
  12. -Bubnova, R.S., Stepanov, N.K., Levin, A.A., Filatiov, S.K., Paufler, P. and Meyer, D.C., 2004. Crystal structure and thermal behaviour of boropollucite CsBSi2O6, Solid State Sciences, v. 6, p. 626-637.
  13. -Carr, P.F., Perkns, M. and Moradian, A., 1996. Large pseudomorphous trapezohedra of analcime and pumpellyite after leucite, Aghda area, Central Iran: Mineralogy and Petrology, v. 58, p. 23-32.
  14. -Comin-Chiaramonti, P., Meriani, S., Mosca, R. and Sinigoi, S., 1979. On the occurrence of analcite in the northeastern Azerbaijan volcanics (northwestern Iran): Lithos, v. 12, p. 187- 198.
  15. -Giampaolo, C. and Lombardi, G., 1994. The thermal behaviour of Analcites from tow different genetic environment: European journal of mineralogy, v. 6(2), p. 285-289.
  16. -Giannetti, B. and Masi, U., 1989. Trace-element behavior during weathering ofleucite in potassic rocks from the Roccamonfina volcano (Campania, southern Italy) and environmental implications: Lithos, v. 22, p. 317-324.
  17. -Gupta, A.K. and Fyfe, W.S., 1975. Leucite survival; the alteration to analcime: The Canadian Mineralogist, v. 13, p. 361-363.
  18. -Hassanzadeh, J., 1993. Metallogenic and tectono-magmatic events in the SE sector of the Cenozoic active continental margin of Central Iran (Shahr-e Babak area, Kerman Province), Ph.D. dissertation, University of California, Los Angeles, 204p.
  19. -Henderson, C.M.B. and Gibb, F.G.F., 1977. Formation of analcime in the Dippin sill, Isle of Arran: Mineralogical Magazine, v. 41, p. 534-537.
  20. -Hushmandzadeh, A.R., Alavi Naini, M. and Haghipour, A.A., 1978. Evolution of geological phenomenon in Torud area: Geological Survey of Iran, Tehran, 136 p.
  21. -Karlsson, H.R. and Clayton, R.N., 1991. "Analcime phenocrysts in igneous rocks-primary or secondary": American Mineralogist, v. 76, p. 189-199.
  22. -Karlsson, H.R. and Clayton, R.N., 1991. Analcime phenocrysts in igneous rocks; primary or secondary American Mineralogist, v.76, p. 189-199.
  23. -Karlsson, H.R. and Clayton, R.N., 1993. Analcite phenocrysts in igneous rocks: Primary or secondary reply: American Mineralogist, v. 78, p. 230-232.
  24. -Kim, K.T. and Burley, B.J., 1971. Phase equilibria in the system NaAlSi3O8-NaAlSi04-H2O with special emphasis on the stability of analcite: Canadian Journal of Earth Sciences, v. 8, p. 311-337.
  25. -Line, C.M.B., Putnis, A., Putnis, C. and Giampaolo, C., 1995. The dehydration kinetics and microtexture of analcite from two paragenesis: American Mineralogist, v.80, p. 268-279.
  26. -Liou, J.G., 1971. Analcime equilibria: Lithos, v. 4, p. 389-402.
  27. -Luhr, J.F. and Giannetti, B., 1987. The brown leucititic tuff of Roccamonfina Volcano (Roman Region, Italy): Contributions to Mineralogy and Petrology, v. 95, p. 420-436.
  28. -Luth, R. and Bowerman, M., 2004. Microtextural and powder diffraction study of analcime phenocrysts in the Crowsnest Formation, Southern Alberta, Canada: Can. Mineral, v. 42, p. 897-903.
  29. -Moradian, A., 2008. A contribution to the genesis of analcite after leucite in potassic volcanic rocks of the Nadik area, Kerman, Iran Journal of Sciences Islamic Republic of Iran, v. 19, p. 31-48.
  30. -Morse, S.A., 1968. Syenite, Camegie Institution of Washington Year Book, v. 68, p. 112-120.
  31. -Morimoto, N., Fabries, J., Fergusson, A. K., Guizbourg, I. D., Ross, M., Seifert, F. A., Zussman, J., Aoki, K. and Gottardi, G., 1988. Nomenclature of pyroxenes: American Mineralogist, v. 173, p. 1123-1133.
  32. -Norish, K. and Chappell, B.W., 1977. X-ray fluorescence spectrometry. In: Zussman J. (Ed.), Physical Methods in Determinative Mineralogy, 2nd Ed, Academic Press, London, 71p.
  33. -Paukov, I.E., Belitsky, I.A. and Fursenko, B.A., 2002. Heat capacity and thermodynamic functions of leucite at low temperatures, Thermochemica Acta, v. 387, p. 23-28.
  34. -Pearce, T.H., 1970. The analcite-bearing volcanic rocks of the Crowsnest Formation, Alberta: Canadian Journal of Earth Sciences, v. 7, p. 46-66.
  35. -Pearce, T.H., 1993. Analcime phenocrysts in igneous rocks; primary or secondary? Discussion: American Mineralogist, v. 78, p. 225-229.
  36. -Pearce, T.H., 1993. Primary or secondary analcime –Discussion: American Mineralogist, v, 78, p. 225-229.
  37. -Peters, L. and Tuttle, O.F., 1966. The melting of analcite solid solutions in the system NaAlSiO4-NaAlSi3O8-H2O: American Mineralogist, v. 3, p. 736-753.
  38. -Prelevic, D., Foley, S.F., Cvetkovic, V. and Romer, R.L., 2004. Origin of minetter by mixing of lamproite and dacite magmas in Velili Majdan, Serbia: Journal of Petrology, v. 45, p. 759-792.
  39. -Pirsson, L.V., 1896. On the monchiquites or analcite group of igneous rocks: Journal of Geology, v. 4, p. 619-690.
  40. -Redkin, A.F. and Hemley, J.J., 2000. Experimental Cs and Sr sorption on analcime in rock-buffered systems at 250-300 degrees C and P sat and the thermodynamic evaluation of mineral solubilities and phase relations: European Journal of Mineralogy, v. 12, p. 999-1014.
  41. -Riou, R., Dupuy, C. and Dostal, J., 1981. Geochemistry of coexisting alkaline and calcalkaline volcanic rocks from northern Azerbaijan (N.W. Iran): The Journal of Volcanology and Geothermal Research, v. 11, p. 253-275.
  42. -Rock, N.M.S., 1977. The nature and origin of lamprophyres: Some definitions, distinctions, and derivatives: Earth-Science Reviews, v, 13, p. 123-169.
  43. -Roux, J. and Hamilton, D.L., 1976. Primary igneous analcite- An experimental study: Journal of Petrology, v. 17, p. 244-257.
  44. -Saha, P., l96l. The system NaAlSiO4 (nepheline)-NaAlSi3O8, (albite)-H2O: American Mineralogist, v. 46, p. 859-884.
  45. -Sharkovski, M., Susov, M. and Krivyakin, B., 1984. Geology of the Anarak area (Central Iran), Report, Geological Survey of Iran, Tehran, 143p.
  46. -Stalder, P., 1971. Magmatisme tertiaire et subrecent entre Taleghan et Alamout, Elbourz Central (Iran): Scheweitz. Min. Petr. Mitt, v. 51, 138 p.
  47. -Taylor, D. and Mackenzie, W.S., 1975. "A contribution to the pseudoleucite problem": Contribution to mineralogy and petrology, v. 49, p. 321-333.
  48. -Weisenberger, T. and Spurgin, S., 2009. Zeolite in alkaline rocks of the Kaiserstuhl volcanic complex, SW Germany-new microprobe investigation and relationship of zeolite mineralogy to the host rock: Geology, Bekgica, v. 12, p. 75-91.
  49. -Wilkinson, J.F.G., 1965. Some feldspars, nephelines and analcimes from the Square Top Intrusion, Nundle, N.S.W: Joumal of Petrology, v. 6, p. 420-444.
  50. -Wilkinson, J.F.G., 1977. Analcime phenocrysts in a vitrophyric analcimite-Primary or secondary? Contributions to Mineralogy and Petrology, v. 64, p. l-l0.
  51. -Wilkinson, J.F.G. and Hensel, H.D., 1991. An analcime augerite-mega-cryst association from north-eastern New South Wales: implications for high pressure amphibole- dominated fractionation of alkaline magmas: Contributions Mineral Petrology, v. 109, p. 240-251.
  52. -Williams, H., Turner, F.J. and Gilbert, C.M., 1982. Petrography: An Introduction to the Study of Rocks in Thin Sections, 2nd Ed., W.H. Freeman, San Francisco, 626 p.
  53. -Woolley, A.R. and Symes, R.F., 1976. The analcime-phyric phonolites (blairmorites) and associated analcime kenyaites of the Lupata Gorge, Mocambique: Lithos, v. 9, p. 9-15.

فایل ها

هم رسانی

ارجاع به این مقاله

آمار