شیمی برخی از کانی‌ها و ارزیابی دما و فشار در توده گرانیتوئیدی کوه دم، شمال شرق اردستان

نویسندگان

1 دانشگاه تهران

2 دانشگاه پیام نور مرکز اصفهان

چکیده

توده گرانیتوئیدی کوه دم، واقع در شمال شرق اردستان، بیشتر از گرانودیوریت و کمی دیوریت تشکیل شده است. بخش‌های گرانودیوریتی این مجموعه به وسیله دایک‌هایی بازی متعدد قطع شده‌اند. کانی‌های اصلی تشکیل دهنده سنگ‌های منطقه شامل پلاژیوکلاز، آلکالی‌فلدسپار، کوارتز، بیوتیت، آمفیبول، و پیروکسن­اند. نتایج ریز پردازش آنها نشان می‌دهد که بیوتیت‌های گرانودیوریت‌ و دیوریت از نوع منیزیم‌دار و متعلق به سری کالک‌آلکالن کوهزایی هستند. آمفیبول‌های این مجموعه، کلسیک و ترکیب آن‌ها از منیزیوهورنبلند تا اکتینولیت در گرانودیوریت‌ها و از اکتینولیت‌هورنبلند تا اکتینولیت در دیوریت‌ها و دایک‌های بازیک تغییر می‌کند. ترکیب پلاژیوکلازها در گرانودیوریت‌ها از الیگوکلاز تا آندزین و در دیوریت‌ها و دایک‌های بازیک از آندزین تا لابرادوریت متغیر است. مطالعات زمین دما-فشارسنجی گرانودیوریت‌ها حاکی از آن است که میانگین فشار و دمای حاکم بر توده هنگام جایگزینی به ترتیب در حدود 5/1 کیلوبار و 700 درجه سانتیگراد بوده است. این فشار با توجه به میانگین چگالی سنگهای پوسته‌، با عمق در حدود 5/5 کیلومتری همخوانی دارد.

کلیدواژه‌ها


عنوان مقاله [English]

Mineral chemistry and thermobarometry of Kuh e-Dom granitoid, NE Ardestan

چکیده [English]

Kuh e-Dom intrusion, located at the northeast of Ardestan, consists of granodiorite and diorite. The granodiorites have been intruded by various basic dikes. Plutonic rocks are mainly composed of plagioclase, biotite, amphibole, pyroxene, alkali-feldspar and quartz. Based on microprobe analysis, the biotite is classified as magnesiobiotites which typically occur at calc-alkaline orogenic igneous rocks. The amphibole belongs to calcic-amphibole group but its composition varies from magnesiohornblende to actinolite in granodiorite and from hornblende-actinolite to actinolite both in diorite and basic dikes. The plagioclase also shows variable composition from oligoclase to andesine in the granodiorite and from andesine to labradorite both in diorite and basic dikes. Based on the mineral chemistry data, the equilibrium temperature of the mineral crystallization is estimated at about 700°C, the pressure equilibrium occurred at ~1.5 Kb, which is consistent with a depth of 5.5 Km .

کلیدواژه‌ها [English]

  • Mineral chemistry
  • Granodiorite
  • geothermometry
  • geobarometry
  • Kuh e-Dom
[1] Technoexport., "Detail geology prospecting in the Anarak Area Central Iran", Geological Survey of Iran, Report No. 9 (1981) 154p.

[2] Droop G.T.R., "A general equation Fe3+ concentration in ferromagnesian silicates and oxides from microprobe analysis using stoichiometric criteria", Mineralogical Magazine 51 (1987) 431-435.

[3] Leake B.E., Woolly A.R., Arps C.E.S., Birch W.D., Gilbert M.C., Grice J.D., Hawthorne F.C., Kato A., Kisch H.J., Krivovichev V.G., Linthout K., Laird J., Mandarino J., Maresch W.V., Nickel E.h., Rock N.M.S., Schmucher J.C., Smith D.C., Stephenson N.C.N, Unungaretti L., Whittaker E.J.W., Youzhi G., "Nomenclature of Amphiboles. Report of the Subcommittee on Amphiboles of the International Mineralogical Association Commission on New Minerals Names", Europian Journal of Mineralogy 9 (1997) 623-651.

[4] Shelly D., "Igneous and metamorphic rocks under the microscope", Chapman & Hall, (1993) 630p.

[5] Forster M.D., "Interpretation of the composition of tri octahedral mica", U.S Geological Survey. Prof. Pap. 354B (1960) 1-48.

[6] Rieder M., Cavazzini G., Dُyakonov Y.u., Frank-Kamenetskii V.A., Gottardi G., Guggenheim S., Koval P.V., Muller G., Neiva A.M.R., Radoslovich E.W., Robert J.L., Sassi F.P., Takeda H., Weiss Z., Wones D.R., "Nomenclature of the micas", The Canadian Mineralogist 63 2 (1999) 267-279.

[7] De Pieri R., Jobstraibizer P.G., "Crystal chemistry of biotite from dioritic to granodioritic rock type of Adamello massif (Northern Italy)", Neues Jahrbuch Min Ahb 148 (1983) 58-82.

[8] Nachit H., Ibhi A., Abia E.1.H., Ohoud M.B., "Discrimination between primary magmatic biotites, re-equilibrated biotites and neoformed biotites", C. R. Acad. Science. Paris Geoscience 337 (2005) 1415-1420.

[9] Partin E., Hewitt D.A., Wones D.R., "Quantification of ferric iron in biotite", Geological Society American. Abstract With program 15 (1983) 659.

[10] Wones D.R., Burns R.G., Carrol B.M., "Stability and properties of synthetic annite", American Geophysics. :union: Trans. 52 (1971) 369.

[11] Abbot R.N., Clarke D.B., "Hypothetical liquidus relationships in the subsystem Al2O3-FeO-MgO projected from quartz, alkali feldspar and plagioclase for (H2O)<1", Canadian Mineralogist 17 (1979) 549-560.

[12] Abdelrahman A.M., "Nature of biotites from Alkaline, Calc-alkaline and Peraluminous magmas", Journal of Petrology 35 (1994) 525-541.

[13] Nachit H., "Contribution a l e′ tude analytique et experimental des biotite des granitoids Applications typologiques", These De Doctorat De Lُ Universite De Bretagne Occidentale (1986) 236p.

[14] Shabani A.T., Lalonde A.E., Whalen J.B., "Composition of biotite from granite rocks of the Canadian Appalachian orogen: A potential tectonomagmatic indicator?" The Canadian Mineralogist (2003) 1381-1396.

[15] Chppel B.W., White A.J.R., "Two contrasting granite types", Pacific Geology 8 (1974) 173-174.

[16] White A.J.R., Chppel B.W., "Granitoid types and their distribution in the Lachlan Fold Belt, southeastern Australia", Geological Society American Memory 159 (1983) 21-34.

[17] Wyborn D., Chappel B.W., Johnston R.M., "Three S type volcanic suites from the Lachlan Fold Belt. Southeast Australia", Journal Geophysics Research 86 (1981) 10335-10348.

[18] Clemens J.D., Wall V. J., "Origin and evolution of a peraluminous silicic ignimbrite suite: the Violet Town Volcanics", Contribution to Mineralogy and Petrology 88 (1984) 354-371.

[19] Henes-Klaiber U., "Zur Geochemie der variszischen granitoid des bergstrasser Odenwaldes", Thesis. Tu Karlsruhe (1992) 264 p.

[20] Celic O.F., Delaloye M.F., "Characteristics of ophiolite-related metamorphic rocks in the Beysehir ophiolitic mélange (Central Taurides, turkey), Deduced from whole rock and mineral chemistry", J. of Asian Earth Science 26 (2006) 452-476.

[21] Deer W.A., Howie R.A., Zussman J., "An introduction to the Rock forming minerals" , 17th, ongman, Ltd, (1991) 528 p.

[22] Esawi E.K., "AMPH-CLASS: An excel spreadsheet for the classification and nomenclature of amphibole based on the 1997 recommendations of the international mineralogical Association", Computers Geosciences 30 (2004) 753-760.

[23] Blundy J.D., Holland T.J.B., "calcic amphibole equilibria and a new amphibole- plagioclase geothermometer", Contribution to Mineralogy and Petrology 104 (1990) 208-224.

[24] Hammarstrom J.M., Zen E., "Aluminum in hornblende: An empirical igneous geobarometer", American Mineralogist 71 (1986) 1297-1313.

[25] Stein E., Dietl E., "Hornblende thermo barometry of granitoids from the central Odenwald (Germany) and their implication for the geotectonic development of the Odenwald", Mineralogy and Petrology 72 (2001) 185-207.

[26] Helmy H.M., Ahmed A.F., E1Mahallawi M.M., Ali S.M., "Pressure, temperature and oxygen fugacity conditions of calc-alkaline granitoids. Eastern Desert of Egypt and tectonic implication", J. of African Earth Science 38 (2004) 255-268.

[27] Anderson J.L., Smith D.R., "The effects of temperature and ƒO2 on the Al-in-hornblende barometer", American Mineralogist 80 (1995) 549-559.

[28] Hollister LS., Grissom G.C., Peters E.K., Stowell H.H., Sisson V.B., "Confirmation of the empirical correlation of Al in hornblende with pressure of solidification of clac-alkaline plutons", American Mineralogist 72 (1987) 231-239.

[29] Johnson M.C., Rutherford M.J., "Experimental calibration of the aluminum-in-hornblende geobarometer with applications to Long Valley Caldera (California) volcanic rocks", Geology 17 (1989) 837-841.

[30]Thomas W.M., Ernst W.G., "The aluminum content of hornblende in calc-alkaline granitic rocks: a mineralogic barometer calibrated experimentally to 12 Kbar. In: spencer Rj. Chou IM (eds) Fluid-mineral interactions: a tribute to HP Eugster", Geochemical Society special publication 2 (1990) 59-63.

[31] Schmidt M.W., "Amphibole composition in tonalite as a function of pressure an experimental calibration of the Al-hornblende barometer". Contribution to Mineralogy and Petrology 110 (1992) 304-310.

[32] Poli S., Schmidt M.W., "A comment on Calcic-amphibole equilibria and a new amphibole-plagioclase geothermometer by Blundy J.D., and Holland TJB", Contribution to Mineralogy and Petrology 111 (1992) 273-282.

[33] Jarrar G., "Mineral chemistry in dioritic hornblendites from Wadi Araba, southwest Jordan", J. of African Earth Science 26 (1998) 285-295.

[34] Kroll H., Evangelakakis C., Voll G., "Two feldspar geothermometery: a review and revision for slowly cooled rocks", Contribution to Mineralogy and Petrology (1993) 510-518.

[35] Anderson J.L., "Status of thermo-barometry in granitic batholiths", Earth Science Review 87 (1996) 125-138.

[36] Blundy J.D., Holland T.J.B., "Calcic amphibole equilibria and a new amphibole- plagioclase geothermometer; replay to the comments of hammarstrom and Zen, and Rutherford and Johnson", Contribution to Mineralogy and Petrology 111 (1992) 269-272.

[37] Holland T., Blundy J., "Non-ideal interactions in calcic-amphiboles and their bearing on amphibole-plagioclase thermometry", Contribution to Mineralogy and Petrology 11 (1994) 6 433-447.

[38] Clarke D.B., "Granitoid rocks", Champan & Hall. (1992) 280p.

[39] Vihnal C.R., Mcsween H.Y., Speer J.A., "Hornblende Chemistry in Southern Appalachian Granitoids: implications for aluminum hornblende thermo barometry and magmatic epidote stability", American Mineralogist 76 (1991) 176-188.

[40] Winkler H.G.F. Die Genese der metamorphic gesteine 1965: Berlin New York, Springer verlag.