بررسی شواهد ساختاری و دمافشارسنجی سنگ‌های دگرگونی شمال اسدآباد (پهنه سنندج-سیرجان)

نوع مقاله : مقاله پژوهشی

نویسندگان

دانشگاه پیام نور

چکیده

تاق‌شکل آلماقلاغ در شمال اسدآباد همدان از مناطقی است که واحدهای سنگی پالئوزوئیک پهنه سنندج- سیرجان در آن رخنمون دارند. این تاق‌شکل شامل دو مجموعه دگرگونی آلماقلاغ در بخش زیرین با سنگ­مادر غالب آتشفشانی و مجموعه چنارشیخ در بخش بالایی با سنگ­مادر غالب رسوبی است. توده‌های نفوذی فلسی و مافیک با سن ژوراسیک پسین- کرتاسه پیشین در مرکز این تاق‌شکل جای گرفته‌اند. یک مرحله از دگرگونی ناحیه‌ای عامل بوجود آورنده برگوارگی S1 در همه این توالی‌های سنگی است. دماسنجی به روش آمفیبول-پلاژیوکلاز و فشارسنجی به روش آمفیبول-پلاژیوکلاز-گارنت-کوارتز بر متابازیت‌های مجموعه آلماقلاغ بیانگر اعمال فاز دگرگونی در دمای میانگین 570 درجه سانتیگراد و فشار میانگین 2/7 کیلوبار است. همچنین دماسنجی به روش بیوتیت-گارنت و فشارسنجی به روش گارنت-پلاژیوکلاز-بیوتیت-مسکوویت-کوارتز و گارنت-پلاژیکلاز-مسکوویت-کوارتز بر سنگ‌های متاپلیتی مجموعه چنارشیخ نشانگر شرایط دگرگونی در دمای میانگین 462 درجه سانتیگراد و فشار میانگین 6/2 کیلوبار است. این شرایط دما و فشار بیانگر آن است که درجه دگرگونی ناحیه‌ای منطقه تا رخساره آمفیبولیت پیش رفته و همچنین درجه دگرگونی در بخش­های زیرین توالی سنگی تاقدیس آلماقلاق بیشتر است. برگوارگی S2 که طی یک نظام زمین­ساختی برشی ایجاد شده است، نافذترین ساختار زمین­ساختی در همه توالی‌های سنگی منطقه است. توده‌های نفوذی ژوراسیک پسین- کرتاسه پیشین همزمان با این زمین­ساخت برشی جایگیری کرده‌اند، به طوری‌که علاوه بر تاثیر بر روند و شیب برگوارگی S2، خود نیز متاثر از این زمین­ساخت برشی شده‌اند. جایگیری این توده‌های نفوذی مهمترین عامل در ایجاد ساختار گنبدی منطقه است.    

کلیدواژه‌ها

عنوان مقاله [English]

Structural and thermobarometric investigations of metamorphic rocks in the north of Asadabad (Sanandaj-Sirjan zone)

نویسندگان [English]

  • behnaz Hosseini
  • AhmadReza Ahmadi
چکیده [English]

The Almaghoulagh antiform in north of Asadabad, Hamedan, is one of the areas where the Paleozoic rocks are exposed in the Sanandaj-Sirjan zone. The antiform comprises two metamorphosed units. The Almaghoulagh unit in the lower part is overlain by the Chenar Sheikh unit, whereas the former derived from a volcanic protolith, the latter had a protolith with a significant sedimentary component. The Late Jurassic and Early Cretaceous felsic and mafic plutonic bodies are situated in the core of the antiform. The S1 foliation, which can be recognized throughout all the lithological units, is considered to formed during a regional metamorphic event. The amphibole-plagioclase thermometer and amphibole-garnet-plagioclase-quartz barometer yielded metamorphic temperature of 570°C and an average pressure of 7.2 kbar for the Almaghoulagh metabasites. The P-T condition of metamorphism in the Chenar sheikh metapelites was also estimated at 462° C and an average pressure of  2.6 kbar using the biotite-garnet thermometer and garnet-plagioclase-biotite-muscovite-quartz and garnet-plagioclase-muscovite-quartz barometers. These P-T estimations suggest that the regional metamorphism reached the amphibolite grade and the lower part of the Almaghoulah antiform experienced a higher degree of metamorphism.  The S2 foliation, which is the most penetrative structural element of all the rock units in the region, formed within a shear zone. Occurrence of the shear stress in the region, facilitated intrusion of the Late Jurassic and Early Cretaceous plutonic bodies into the core of the antiform. The emplacement of the plutonic bodies has played a major role in folding and doming the region.

کلیدواژه‌ها [English]

  • thermometery
  • barometery
  • regional metamorphism
  • Almaghoulagh antiform
  • Sanandaj-Sirjan Zone

مراجع

  1. [1] Vernon R. H., "A Practical Guide to rock Microstructure", Cambridge University Press (2004). [DOI:10.1017/CBO9780511807206]
  2. [1] Vernon R. H., "A Practical Guide to rock Microstructure", Cambridge University Press (2004). [DOI:10.1017/CBO9780511807206]
  3. [2] Vernon R. H., Clark G. l., "Principles of metramorphic Petrology", Cambridge University Press (2008).
  4. [2] Vernon R. H., Clark G. l., "Principles of metramorphic Petrology", Cambridge University Press (2008).
  5. [3] Harley S. L., Thompson P., Hensen B. J., Buick I. S., "Cordierite as a sensor of fluid conditions in high-grade metamorphism and crustal anataxis", Journal of Metamorphic Geology 20 (2002) 71-86. [DOI:10.1046/j.0263-4929.2001.00344.x]
  6. [3] Harley S. L., Thompson P., Hensen B. J., Buick I. S., "Cordierite as a sensor of fluid conditions in high-grade metamorphism and crustal anataxis", Journal of Metamorphic Geology 20 (2002) 71-86. [DOI:10.1046/j.0263-4929.2001.00344.x]
  7. [4] Kalt A., "Cordierite channel volatiles as evidence for dehydration melting: an example from high-temperature metapelites of the Bayerische Wald (Variscan belt, German)", European Journal of Mineralogy 12 (2000) 987–998. [DOI:10.1127/ejm/12/5/0987]
  8. [4] Kalt A., "Cordierite channel volatiles as evidence for dehydration melting: an example from high-temperature metapelites of the Bayerische Wald (Variscan belt, German)", European Journal of Mineralogy 12 (2000) 987–998. [DOI:10.1127/ejm/12/5/0987]
  9. [5] Kolesov B. A., Geiger C. A., "Cordierite II: The role of CO2 and H2O", American Mineralogist 85 (2000) 1265–1274. [DOI:10.2138/am-2000-8-919]
  10. [5] Kolesov B. A., Geiger C. A., "Cordierite II: The role of CO2 and H2O", American Mineralogist 85 (2000) 1265–1274. [DOI:10.2138/am-2000-8-919]
  11. [6] Moazzen M., Droop G. T. R., Harte B., "Abrupt transition in H2O activity in the melt-present zone of a thermal aureole: evidence from H2O contents of cordierites", Geology 29 (2001) 311–314.

    https://doi.org/10.1130/0091-7613(2001)0292.0.CO;2 [DOI:10.1130/0091-7613(2001)0292.0.CO;2]
  12. [6] Moazzen M., Droop G. T. R., Harte B., "Abrupt transition in H2O activity in the melt-present zone of a thermal aureole: evidence from H2O contents of cordierites", Geology 29 (2001) 311–314.

    https://doi.org/10.1130/0091-7613(2001)0292.0.CO;2 [DOI:10.1130/0091-7613(2001)0292.0.CO;2]
  13. [7] Rigby M. J., "Cordierite as a Monitor of Volatile Content during Metamorphism and Partial Melting", PhD Thesis, University of Manchester, Manchester.
  14. [7] Rigby M. J., "Cordierite as a Monitor of Volatile Content during Metamorphism and Partial Melting", PhD Thesis, University of Manchester, Manchester.
  15. [8] Rigby M. J., DROOP G. T. R., Bromiley G. D., "Variations in fluid activity across the Etive thermal aureole, Scotland: evidence from cordierite volatile contents", Journal of metamorphic Geology 26 (2008) 331–346. [DOI:10.1111/j.1525-1314.2007.00752.x]
  16. [8] Rigby M. J., DROOP G. T. R., Bromiley G. D., "Variations in fluid activity across the Etive thermal aureole, Scotland: evidence from cordierite volatile contents", Journal of metamorphic Geology 26 (2008) 331–346. [DOI:10.1111/j.1525-1314.2007.00752.x]
  17. [9] Berthier F., Billiaul H.P., Halbrorom B., Marizot P., "Tude Stratigraphique, Petrologiqueet structural de La region de Khorramabad (Zagros, Iran)", These De 3e Cycle, Grenoble, France (1974) pp. 282.
  18. [9] Berthier F., Billiaul H.P., Halbrorom B., Marizot P., "Tude Stratigraphique, Petrologiqueet structural de La region de Khorramabad (Zagros, Iran)", These De 3e Cycle, Grenoble, France (1974) pp. 282.
  19. [10] Masoudi F., "Contact metamorphism and pegmatite development in the region SW of Arak, Iran", PhD thesis, Leeds University, UK (1997).
  20. [10] Masoudi F., "Contact metamorphism and pegmatite development in the region SW of Arak, Iran", PhD thesis, Leeds University, UK (1997).
  21. [11] Heydarianmanesh A., Tahmasebi Z., Ahmadi- Khalaji A., "Mineral chemistry and thermobarometry of migmatitic rocks of Boroujerd area (north of Sanandaj-Sirjan zone) (in Persian)", Petrology 25 (2016) 117-138.
  22. [11] Heydarianmanesh A., Tahmasebi Z., Ahmadi- Khalaji A., "Mineral chemistry and thermobarometry of migmatitic rocks of Boroujerd area (north of Sanandaj-Sirjan zone) (in Persian)", Petrology 25 (2016) 117-138.
  23. [12] Tahmasbi Z., "The role of garnet in interpretation of petrogeneses granitoid Boroujerd complex and its metamorphic areoule (in Persian)", Irainan Journal of crystallography and mineralogy 21 (2013) 57-70.
  24. [12] Tahmasbi Z., "The role of garnet in interpretation of petrogeneses granitoid Boroujerd complex and its metamorphic areoule (in Persian)", Irainan Journal of crystallography and mineralogy 21 (2013) 57-70.
  25. [13] Mohajjel M., "Structure and tectonic evolution of Paleozoic-Mesozoic rocks, Sanandaj-Sirjan zone, Western Iran", Ph.D. Thesis, University of Wollongong, Australia (1997).
  26. [13] Mohajjel M., "Structure and tectonic evolution of Paleozoic-Mesozoic rocks, Sanandaj-Sirjan zone, Western Iran", Ph.D. Thesis, University of Wollongong, Australia (1997).
  27. [14] Mohajjel M., Fergusson C.L., Sahandi M.R., "Cretaceous-Tertiary convergence and continental collision, Sanandaj-Sirjan zone, Western Iran", Journal of Asian Earth Sciences 21 (2003) 379-412. [DOI:10.1016/S1367-9120(02)00035-4]
  28. [14] Mohajjel M., Fergusson C.L., Sahandi M.R., "Cretaceous-Tertiary convergence and continental collision, Sanandaj-Sirjan zone, Western Iran", Journal of Asian Earth Sciences 21 (2003) 379-412. [DOI:10.1016/S1367-9120(02)00035-4]
  29. [15] Stoklin J., "Structural histiry and tectonics of Iran, A review", American Association Petroleum Geologists 52 (1968) 1229-1258.
  30. [15] Stoklin J., "Structural histiry and tectonics of Iran, A review", American Association Petroleum Geologists 52 (1968) 1229-1258.
  31. [16] Ahmadi-Khalaji A., Esmaeily D., Valizadeh M. V., Rahimpour-Bonab H., "Petrology and Geochemistry of the Granitoid Complex of Boroujerd, Sansandaj-Sirjan Zone, Western Iran", Journal of Asian Earth Sciences, 29 (2007) 859-877 [DOI:10.1016/j.jseaes.2006.06.005]
  32. [16] Ahmadi-Khalaji A., Esmaeily D., Valizadeh M. V., Rahimpour-Bonab H., "Petrology and Geochemistry of the Granitoid Complex of Boroujerd, Sansandaj-Sirjan Zone, Western Iran", Journal of Asian Earth Sciences, 29 (2007) 859-877 [DOI:10.1016/j.jseaes.2006.06.005]
  33. [17] Masoudi F., Yardley B.W.D., Cliff R.A., "Rb-Sr geochronology of pematites, plutonic rocks and a hornfels in the region southwest of Arak, Iran", Journal of Sciences 13 (2002) 249-254.
  34. [17] Masoudi F., Yardley B.W.D., Cliff R.A., "Rb-Sr geochronology of pematites, plutonic rocks and a hornfels in the region southwest of Arak, Iran", Journal of Sciences 13 (2002) 249-254.
  35. [18] Ahmadi-Khalaji A., Tahmasbi Z., Keshtgar Sh., "A new view on the metamorphic rocks of the Boroujerd area (in Persian) ", Journal of Geotechnical Geology 2 (2010) 71-81.
  36. [18] Ahmadi-Khalaji A., Tahmasbi Z., Keshtgar Sh., "A new view on the metamorphic rocks of the Boroujerd area (in Persian) ", Journal of Geotechnical Geology 2 (2010) 71-81.
  37. [19] Clemens J. D., Wall V. J., "Crystallisation and origin of some peraluminous (S-type) granitic magmas", Cantributions to Mineralogy and Petrology 14 (1981) 111-132.
  38. [19] Clemens J. D., Wall V. J., "Crystallisation and origin of some peraluminous (S-type) granitic magmas", Cantributions to Mineralogy and Petrology 14 (1981) 111-132.
  39. [20] Clemens J. D. and Vielzeuf D., "Constraints on melting and magma production in the crust", Earth and Planetary Science Letters, 86 (1987) 287-306. [DOI:10.1016/0012-821X(87)90227-5]
  40. [20] Clemens J. D. and Vielzeuf D., "Constraints on melting and magma production in the crust", Earth and Planetary Science Letters, 86 (1987) 287-306. [DOI:10.1016/0012-821X(87)90227-5]
  41. [21] Pati-o Douce A. E., Johnstone A. D., "Phase equilibria and melt productivity in the pelitic system: implications for the origin of peraluminous granitoids and aluminous granites", Contributions to Mineralogy and Petrology 107 (1991) 202-218. [DOI:10.1007/BF00310707]
  42. [21] Pati-o Douce A. E., Johnstone A. D., "Phase equilibria and melt productivity in the pelitic system: implications for the origin of peraluminous granitoids and aluminous granites", Contributions to Mineralogy and Petrology 107 (1991) 202-218. [DOI:10.1007/BF00310707]
  43. [22] Stevens G., Clemens J. D., Droop G. T. R., "Melt production during granulite-facies anatexis: experimental data from "primitive" metasedimentary protoliths", Contributions to Mineralogy and Petrology 28 (1997) 352-370. [DOI:10.1007/s004100050314]
  44. [22] Stevens G., Clemens J. D., Droop G. T. R., "Melt production during granulite-facies anatexis: experimental data from "primitive" metasedimentary protoliths", Contributions to Mineralogy and Petrology 28 (1997) 352-370. [DOI:10.1007/s004100050314]
  45. [23] Vielzeuf D., Hollowa, J. R., "Experimental determination of the fluid- absent melting reactions in the elitic system: consequences for crusta differentiation", Contributions to Mineralogy and Petrology 98 (1988) 257-276. [DOI:10.1007/BF00375178]
  46. [23] Vielzeuf D., Hollowa, J. R., "Experimental determination of the fluid- absent melting reactions in the elitic system: consequences for crusta differentiation", Contributions to Mineralogy and Petrology 98 (1988) 257-276. [DOI:10.1007/BF00375178]
  47. [24] Kretz R., "Symbols for rock-forming minerals", American Mineralogy 68 (1983) 277-279.
  48. [24] Kretz R., "Symbols for rock-forming minerals", American Mineralogy 68 (1983) 277-279.
  49. [25] Yardley B.W.D., "An introduction to Metamorphic Petrology", Longman (1991) 248p.
  50. [25] Yardley B.W.D., "An introduction to Metamorphic Petrology", Longman (1991) 248p.
  51. [26] Deer W. A., Howie R. A., Zussman J., "Rock- forming minerals", 3rd vol., Longman, London (1962).
  52. [26] Deer W. A., Howie R. A., Zussman J., "Rock- forming minerals", 3rd vol., Longman, London (1962).
  53. [27] Coleman R. G., Lee D. E., Beatty L. B., Brannock W. W., "Eclogites and eclogites: their differences and similarities", Geological Society America Bulletin 76(5) (1965) 483-508. [DOI:10.1130/0016-7606(1965)76[483:EAETDA]2.0.CO;2]
  54. [27] Coleman R. G., Lee D. E., Beatty L. B., Brannock W. W., "Eclogites and eclogites: their differences and similarities", Geological Society America Bulletin 76(5) (1965) 483-508. [DOI:10.1130/0016-7606(1965)76[483:EAETDA]2.0.CO;2]
  55. [28] Holland T. J. B., Powell R., "An internally consistent thermodynamic data set for phases of petrological interest", Journal of Metamorphic Geology 16 (1998) 309–344. [DOI:10.1111/j.1525-1314.1998.00140.x]
  56. [28] Holland T. J. B., Powell R., "An internally consistent thermodynamic data set for phases of petrological interest", Journal of Metamorphic Geology 16 (1998) 309–344. [DOI:10.1111/j.1525-1314.1998.00140.x]
  57. [29] Harley S. L., Carrington D. P., "The distribution of H2O between cordierite and granitic melt: Improved calibration of H2O incorporation in cordierite and its application to high-grade metamorphism and crustal anataxis", Journal of Petrology 42 (2001) 1595-1620. [DOI:10.1093/petrology/42.9.1595]
  58. [29] Harley S. L., Carrington D. P., "The distribution of H2O between cordierite and granitic melt: Improved calibration of H2O incorporation in cordierite and its application to high-grade metamorphism and crustal anataxis", Journal of Petrology 42 (2001) 1595-1620. [DOI:10.1093/petrology/42.9.1595]
  59. [30] Thompson P., Harley S. L., Carrington D. P., "H2O-CO2 partitioning between fluid, cordierite and granitic melt at 5 kbar and 900 °C", Contributions to Mineralogy and Petrology 150 (2001) 170-190.
  60. [30] Thompson P., Harley S. L., Carrington D. P., "H2O-CO2 partitioning between fluid, cordierite and granitic melt at 5 kbar and 900 °C", Contributions to Mineralogy and Petrology 150 (2001) 170-190.
  61. [31] Harley S., "Cordierite as a sensor of fluid and melt distribution in crustal metamorphism", Mineraloigical Magazine 58a (1994) 374-375. [DOI:10.1180/minmag.1994.58A.1.196]
  62. [31] Harley S., "Cordierite as a sensor of fluid and melt distribution in crustal metamorphism", Mineraloigical Magazine 58a (1994) 374-375. [DOI:10.1180/minmag.1994.58A.1.196]
  63. [32] Stevens G., Clemens J. D., "Fluid-absent melting and the roles of fluids in the lithosphere: a slanted summary?", Chemical Geology 108 (1993) 1-17. [DOI:10.1016/0009-2541(93)90314-9]
  64. [32] Stevens G., Clemens J. D., "Fluid-absent melting and the roles of fluids in the lithosphere: a slanted summary?", Chemical Geology 108 (1993) 1-17. [DOI:10.1016/0009-2541(93)90314-9]
  65. [33] Carrington D. P., Harley S. L., "Cordierite as a momnitor of fluid and melt water contents in the lower crust: an experimental calibration", Geology 24 (1996) 647- 650.

    https://doi.org/10.1130/0091-7613(1996)0242.3.CO;2 [DOI:10.1130/0091-7613(1996)0242.3.CO;2]
  66. [33] Carrington D. P., Harley S. L., "Cordierite as a momnitor of fluid and melt water contents in the lower crust: an experimental calibration", Geology 24 (1996) 647- 650.

    https://doi.org/10.1130/0091-7613(1996)0242.3.CO;2 [DOI:10.1130/0091-7613(1996)0242.3.CO;2]
  67. [34] Carrington D. P., Harley S. L., "Partial melting and phase relations in high-grade metapelites: an experimental petrogenetic grid in the KFMASH system", Contributions to Mineralogy and Petrology 120 (1995) 270-291. [DOI:10.1007/BF00306508]
  68. [34] Carrington D. P., Harley S. L., "Partial melting and phase relations in high-grade metapelites: an experimental petrogenetic grid in the KFMASH system", Contributions to Mineralogy and Petrology 120 (1995) 270-291. [DOI:10.1007/BF00306508]
  69. [35] Vry J. K., Brown P. E., Valley J. W., "Cordierite volatile content and the role of CO2 in high-grade metamorphism", American Mineralogist 75 (1990) 71-88.
  70. [35] Vry J. K., Brown P. E., Valley J. W., "Cordierite volatile content and the role of CO2 in high-grade metamorphism", American Mineralogist 75 (1990) 71-88.
  71. [36] Johannes W., Holtz F., "Petrogenesis and Experimental Petrology of Granoitic Rocks", Berline: Springer Verlag (1996). [DOI:10.1007/978-3-642-61049-3]
  72. [36] Johannes W., Holtz F., "Petrogenesis and Experimental Petrology of Granoitic Rocks", Berline: Springer Verlag (1996). [DOI:10.1007/978-3-642-61049-3]
  73. [37] Rigby M. J., Droop G. T. R., Bromiley G. D., "Variations in fluid activity across the etive thermal aureole, Scotland: evidence from cordierite volatile contents", Journal of Metamorphic Geology 26 (2008) 331-346. [DOI:10.1111/j.1525-1314.2007.00752.x]
  74. [37] Rigby M. J., Droop G. T. R., Bromiley G. D., "Variations in fluid activity across the etive thermal aureole, Scotland: evidence from cordierite volatile contents", Journal of Metamorphic Geology 26 (2008) 331-346. [DOI:10.1111/j.1525-1314.2007.00752.x]
مجله بلورشناسی و کانی شناسی ایران
دوره 27، شماره 1 - شماره پیاپی 73
فروردین 1398
صفحه 151-166

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  • تاریخ دریافت: 19 اسفند 1396
  • تاریخ بازنگری: 07 خرداد 1397
  • تاریخ پذیرش: 16 تیر 1397

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