پتروگرافی و ژئوشیمی دولومیت‌های بخش زیرین سازند لار در البرز مرکزی، جنوب خاوری بهشهر

نوع مقاله: پژوهشی

نویسندگان

1 دانشجوی دکتری رسوب شناسی و سنگ شناسی رسوبی- دانشگاه آزاد اسلامی واحد تهران شمال

2 عضو هیئت علمی دانشگاه آزاد اسلامی واحد تهران شمال

3 عضو هیئت علمی دانشگاه شهید بهشتی

4 عضو هیئت علمی مجتمع عالی پیامبر اعظم(ص)

5 عضو هیئت علمی دانشگاه آزاد اسلامی- واحد چالوس

چکیده

بررسی‌های پتروگرافی سازند لار در ارتفاعات جنوبی بهشهر در استان مازندران نشان می‌دهد که فرایند دولومیتی شدن به طور گسترده بخش زیرین این سازند را تحت تأثیر قرار داده است. در این پژوهش انواع دولومیت‌های این سازند بر اساس اندازه و فابریک تفکیک شده و سپس ویژگی‌های ژئوشیمیایی و نحوه تشکیل آنها مورد بررسی قرار گرفته است. در برش‌های زیرسطحی مورد مطالعه، پنج نوع دولومیت شامل دولومیت های زنوتاپیک A، ایدیوتاپیک S، ایدیوتاپیک E، ایدیوتاپیک C و زنوتاپیک C شناسایی شد. دولومیت نوع اول تقریباً همزمان با رسوبگذاری و در اثر پمپاژ آب دریا تشکیل شده است. سایر دولومیت‌ها به ترتیب درشت شدن اندازه بلور آنها، در محیط‌های کم عمق تا عمیق تدفینی تشکیل شده‌اند. تغییر ترکیب سیال های دولومیت ساز در طی مراحل اولیه تا تاخیری دیاژنز سبب چنین تنوعی در تشکیل دولومیت های این سازند شده است. با توجه به نتایج آنالیز عنصری، میزان عناصر Ca و Sr از دولومیت نوع اول تا پنجم کاهش یافته و میزان عناصر Fe، Mn و Mg افزایش می یابد. تمرکز Na نیز در دولومیت‌های دیاژنتیک اولیه روندی کاهشی دارد ولی در دولومیت دیاژنتیک تأخیری به دلیل تدفین عمیق و احتمالا تأثیر شورابه‌های حوضه‌ای افزایش می‌یابد.

کلیدواژه‌ها


- آدابی، م.ح.، 1383، ژئوشیمی رسوبی، نشر آرین زمین، 450 ص.

- آدابی، م. ح. و میرشاهانی، م.، 1382، توصیف خصوصیات پتروگرافی و ژئوشیمیایی انواع مختلف دولومیت‌ها در سازند باروت (البرز مرکزی)، مجله علوم دانشگاه تهران، سال بیست و نهم، شماره 1، ص 211 - 187.

- بازرگانی گیلانی، ک. و فرامرزی، م.، 1387، پتروژنزوترکیبدولومیتکرتاسهشهمیرزاد،البرزمرکزی، مجله علوم دانشگاه تهران، ج 34، ص 23-36.

-Adabi, M.H., (1996), Sedimentology and geochemistry of Upper Jurassic (Iran) and Precambrian (Tasmania) carbonates. Unpubl. Ph.D. Thesis, Uni. Tasmania, Australia, p. 400.

-Adabi, M.H., (2002), Petrography and geochemical criteria for recognition of unaltered cold water and diagenetically altered Neoproterozoic dolomite, western Tasmania, Australia. 16th Australian Geology. Conv., Australia (abst.), p. 350.

-Akcay, M., H.M., Ozkan, B., Spiro, R., Wilson, and P.O., Hoskin, (2003), Geochemistry of a high- T hydrothermal dolostone from the Emirli (Odemis, Western Turkey) Sb- Au deposite. Mineral. Mag., v. 67, p.671-688.

-Al-Aasm, I.S. and Packard J.J., (2000), Stabilization of early-formed dolomite: a tale of divergence from two Mississippian dolomites, Sedimentary Geology, v. 131, p. 97-108.

-Amthor, J.E., and Friedman, G.M., (1992), Early to late- diagenetic dolomitization of platform carbonates: Lower Ordovician Ellenburger Group, Permian basin, Australia, Carbonates and Evaporites, v. 13, p. 145-156.

-Azmy, K., Veizer, J., Misi, A., Oliveira, T.F., Sanches, A.L., and Dardenne, M.A., (2001), Dolomitization and isotope stratigraphy of the Vazante Formation, Sao Francisco Basin. Brazil, Precambrian Research, v. 112, p. 303-329.

-Behrens, E.W. and Land, L.S., (1972), Subtidal Holocene dolomite, Baffin Bay, Texas. Bull. Geol. Soc. Am., Abst. with Prog., v. 2, p. 491 -492.

-Brand, U., and Veizer, J., (1980), Chemical diagenesis of multicomponent carbonate system, II: stable isotopes. Jour. Sed. Petrology, v. 51, p. 987-997.

-Burns S.J. and Baker P.A. (1986), A geochemical study of dolomite in the Monterey Formation, California. J. Sed. Pet., v. 57, p. 128-139.

-Cander, H.S, Kaufman, J., Daniels, L.D., and Mayer, W.J., (1988), Regional dolomitization of shelf carbonates in the Burlington-Keokuk Formation (Mississippian), Illinois and Missouri: constraints from cathodoluminescent zonal stratigraphy: in Shukla, V.J, and Baker, P.A., (eds.) Sedimentology and Geochemistry of Dolostones. SEPM. Spec. Pub., v. 43, p. 129-144.

-Chen, D., Qing, H., and Yang C. (2004), Multistage hydrothermal dolomites in the Middle Devonian (Givetian) carbonates from the Guiline area, South China. J. Sedimentology, v. 51, p. 1029-1051.

-Dickson, J.A.D., (1965), A modified staining technique for carbonate in thin section, Nature, 205, p. 587.

-Eren, M., Kaplan, M.Y. and Kadir, S., (2007), Petrography, Geochemistry and Origin of Lower Liassic Dolomites in the AydÝncÝk Area, Mersin, Southern Turkey. Turkish Journal of Earth Sciences. v. 16, p. 339-362

 

-Friedman, G.M., (1965), Terminology of crystallization textures and fabrics in sedimentary rocks. J. Sed. Pet., v. 35, p. 643-655.

-Gregg J.M., and Shelton k.L., (1989), Minor- and trace-element distributions in the Bonneterre Dolomite (Cambrian), southeast Missouri: evidence for possible multiple-basin fluid sources and pathways during lead-zinc mineralization. Geol. Soc. Am. Bulletin, v. 101, p. 221-230.

-Gregg, J.M., and Shelton, K.L., (1990), Dolomitization and neomorphism in the back reef facies of the Bonneterre and Davies Formations (Cambrian), southeastern Missouri. J.Sedimentary Petrology, v. 60, p. 549-562.

-Huebscher, H., and Machel, H.G. (2004), Reflux and burial dolomitization in the Upper Devonian Woodbend Group of north-central Alberta, Canada. Dolomites - The Spectrum: Mechanisms, Models, Reservoir Development. CSPG Seminar and Core Conference, Jan 13-15 2004, Calgary, Alberta, Canada. Abstracts of Seminar Presentations, Core Displays and Posters, C017, p. 19.

-Jones, G.D., Smart, P.L., Whitaker, F.F., Rostron, B.J., and Machel, H.G. (2003), Numerical modeling of reflux dolomitization in the Grosmont platform complex (Upper Devonian), Western Canada sedimentary basin. American Association of Petroleum Geologists Bulletin, v. 87, p. 1273-1298.

-Kirmac, M.Z., and Akdag, K., (2005), Origin of dolomite in the late Cretaceous-Paleocene limestone turbidite, Eastern Pontides, Turkey. Sedimentary Geology, v. 181, p. 39-57.

-Land, L.S., (1980), The isotope and trace element geochemistry of dolomite: the state of the art: in Zenger, D.H., Dunham, J.B., and Ethington, R.L., (eds.), Concepts and Models of Dolomitization:Soc. Econ. Paleontol. Mineral. Spec. Publ., v. 28, p. 87-110.

-Land, L.S., (1985), The origin of massive dolomite. J. Geology. Education, p. 112-125.

-Land, L.S., (1986), Environments of limestone and dolomite diagenesis: some geochemical consideration: In Bathurst, R.G.C., and Land, L.S., (eds.), Carbonate Depositional Environment, Modern and Ancient, part 5, Diagenesis. Quart. Colorado School Mines, v. 81, p. 26-41.

-Land L.S., and Hoops G.K. (1973), Sudium in carbonate sediments and rocks: a possible index to the salinity of diagenetic solutions. J.Sed. Pet. v. 43, p.614-617.

- Lee, Y.I., and Friedman, G.M., (1987), Deepburial dolomitization in the Lower Ordovician Ellenburger Group carbonates in west Texas and southeastern New Mexico. J. Sedimentary Petrology, v. 57, p. 544-557.

-Lumsden, D.N., and Lloyd, R.V., (1997), Three dolomites. J. Sedimentary. Reserch, v. 67, p. 391– 396.

 

-Machel, H.G., (1997), Recrystalization versus neomorphism and the concept of “significant recrystalization” in dolomite research, J. Sedimentary Geology, v.113, p. 161-168.

-Machel, H.G., (2004), Concepts and models of dolomitization: a critical reappraisal, In: C.J.R., Braithwaite, G., Rizi and G., Darke(eds.), The Geometry and Petrogenesis of Dolomite Hydrocarbone Reservoirs, Geological Society of London, Special Publications, no. 235, p. 7-63.

-Machel, H.G., Borrero, M.L., Dembiki, E., Huebscher, H., Ping, L., and Zhao, y., (2012), The Grosmont: a complex dolomitized, fractured and karstified heavy oil reservoir in a Devonian carbonate-evaporite platform, Geo Convention.

-Machel, H.G., and Huebscher, H. (2000), The Devonian Grosmont heavy oil reservoir in Alberta, Canada. Zentralblatt für Geologie und Paläontologie. Teil I, Heft 1/2, p. 55-84.

-Marshall J.D. (1992), Climatic and oceanographic isotopic signals from the carbonate rock record and their preservation. Geol. Mag., v. 129, p. 143-160.

-Mattes, B.W., and Mountjoy, E.W., (1980), Burial dolomitization of the Upper Devonian Miett buildup, Jasper National Park, Alberta: in Zenger, D.H., Dunham, J.B., and Ethington, R.L,. (eds.), Concepts and Models of Dolomitization. Soc. Econ. Paleont. Mineral. Spec. Pub., v. 28, p. 259-297.

-Mazzullo, S.J., (1992), Geochemical and neomorphism alteration of dolomite of dolomite: a review. Carbonate and Evaporite, v. 7, p. 21-37.

-Mazzullo, S.J., (2000), Organogenic dolomitization in peritidal to deep-sea sediments. J. Sedimentary Reserch, v. 70, p. 10- 23.

-Mitchell, J.T., Land, L.S., and Miser, D.E., (1987), Modern marine dolomite cement in a North Jamaica fringing reef. Geology, v. 15, p. 557-560.

-Mukhopodhyay, I., Chanada, S.K., Fukuoka, M., and Chadhri, A.K., (1996), Deep water dolomits from protrozoic Pengana Group in the Prahita Godvar Valey, Andhra Prades, India. J. Sedimentary Reserch, v. 66, p. 223-230.

-Nelson W.A., and Read J. F. (1990), Updip to downdip cementation and dolomitization patterns in a Mississipian aquifer, Appalachians. J. Sed. Pet, v. 60, p. 379-396.

-Qing, H., (1998a), Petrography and geochemistry of early-stage, fine- and medium-crystalline dolomites in the Middle Devonian Presqu'ile at Pine Point, Canada. J. Sedimentology. v. 45,  p. 433-446.

-Radke B.M., and Mathis R.L., (1980), On the formation and occurrence of Saddle dolomite. J. Sed. Pet. v. 56, p. 1149-1168.

-Rao, C.P., (1996), Elemental composition of marine calcite modern temperate shelf branchipods, bryozoance and bulk carbonates, eastern Tasmania, Australia. Carbonates and Evaporites, v. 11, p. 1-18.

-Reinhold, C., (1998), Multiple episodes of dolomitization and dolomite recrystallization during shallow burial in Upper Jurassic shelf carbonates: eastern Swabian Alb, southern Germany. J. Sed. Geol, v. 121, p. 71–95.

-Saller, A.H., (1984), Petrologic and geochemical constrains on the origin of subsurface dolomite, Eniwetak Attol: an example of dolomitization by normal seawater. Geology, v. 12, p. 217-220.

-Schmidt, M., Xeflide, S., Botz, R., and Mann, S., (2005), Oxygen isotope fractionation during synthesis of Ca-Mg carbonate and implications for sedimentary dolomite formation. Geochimica et cosmochimica Acta, v. 69, No.19, p. 4665-4674.

-Sibley, D.F., and Gregg, J.M., (1987), Classification of dolomite rock texture. J. Sedimentary Petrology, v. 57, p. 967-975.

-Suzuki, Y., Iryu, Y., Inagaki, S., Yamada, T., Aizawa, S., and Budd, D.A., (2006), Origin of atoll dolomites distinguished by geochemistry and crystal chemistry: Kita-daito-jima, northern Philippine Sea. Sedimentary Geology, v. 183, p. 181-202.

-Swart, P.K., Cantrell, D.L., Westphal, H., Handford, C.R., and Kendall, C.G., (2005), Origin of dolomite in the Arab-D reservoir from the Ghawar Field, Sudi Arabia: evidence from petrographic and geochemical constraints. J. Sedimentary Petrology Research, v. 75, p. 476-491.

-Tucker, M.E., (1991), Sedimentary Petrology. Black Well, Oxford, p. 260.

-Tucker, M.E., and Wright, V.P., (1990), Carbonate Sedimentology Petrology. Black Well, Oxford, p. 482.

-Veizer, J., (1983), Chemical diagenesis of carbonates: theory and application of trace element technique: Stable Isotopes in Sedimentary Geology: Soc. Econ. Palaeont. Mineral. Short Course, no. 10, p. 1-100.

-Veizer, J., Lemienx , J., Jines, B., Gibling, M.R., and Savelle, J., (1987), Paleosalinity and islands, arctic Canada Can. J. Earth Sci. 15, p. 1448-1461.

-Warren, J.K., (2000), Dolomite: occurrence, evolution and economically important association. Earth- Science Reviews, v. 52, p. 1-81.

-Wacey, D., Wright, D.T., and Boyce, A.J., (2007), A stable isotope study of microbial dolomite formation in the Coorong Region, South Australia, Chemical Geology, v. 244, p. 155-174.

-Whitaker, F.F., Smart, P.L., and Jones, G., (2004), Dolomitization: From conceptual to numerical models, In: C.J.R., Braithwaite, G., Rizi and G., Darke(eds.), The Geometry and Petrogenesis of Dolomite Hydrocarbon Reservoirs. Geological Society of London, Special Publications, no.235, p. 99-139.

 

-Ye, Q., and Mazzullo, S.J., (1992), Dolomitization of Lower Permian platform facies, Wichita Formation, North platform, Midland Basin, Texas. J. Carbonates and Evaporites, v.8, p. 55-70.

-Yoo, C.M., Gregg, J.M., and Shelton, K.L., (2000), Dolomitization and dolomite neomorphism: Trenton and Black River Limestones (Middle Ordovician) Northern Indiana. U.S.A. J. Sedimentary Reserch, v. 70, p. 265–274.