Oxygen isotope clue to migration of dolomitizing fluid as exampled by the Changxing Formation dolomite at Panlongdong, northeastern Sichuan

Abstract

The Upper Permian Changxing dolomite reservoirs serves as one of the most important gas and oil reservoirs in the NE Sichuan Basin. Determining the dolomitizing fluid’s pathway is regarded as the key to solve the “dolomite problem” and further petroleum exploration. Outcrop samples from Upper Permian Changhsingian Panlongdong Section were studied using oxygen isotopic analysis, cathodoluminescence (CL) and major element analysis, in an attempt to determine the migration path way and properties of the dolomitizing fluid. Of the Changxing dolomite, the δ ¹⁸O values ranged from -3.494‰ to -5.481‰, which decreased from the top layer to the bottom in the section; the MgO contents varied from 9.24% to 21.43%, CaO contents from 28.65% to 39.87%, the CaO/MgO ratio from 1.40 to 4.31 and the MnO contents from 0.004% to 0.009 8%. The MgO contents showed a downwardly decreasing trend in the section, while the CaO/MgO showed an opposite rule. All of the dolomites looked dull or dark when they were exposed to the electron beam of the cathodoluminescence device. None of the fine- to medium grained dolomite showed a banded structure. Given that dolomitizing fluid’s salinity decreased during the dolomitization process in its pathway, we concluded that the dolomitizing fluid migrated downwardly in Changxing Formation after excluding the possibility of deep burial or meteoric-marine mixing-water influences. As the dolomitizing fluid’s pathway has always been difficult to be determined in highly dolomitized Formation, this study showed an important application of oxygen isotope values in resolving this problem.

Keywords

Sichuan Basin / Changxing Formation / dolomitization / oxygen isotope / origin / migrating direction

References

[1] Allen J. R., Wiggins W. D. Dolomite Reservoirs: Geochemical Techniques for Evaluating Origin and Distribution. AAPG Continuing Education Course Note Series, 1993, 36: 26-129.

[2] Anderson T. F., Arthur M. A. Stable Isotope of Oxygen and Carbon and Their Application to Sedimentologic and Paleoenvironmental Problems. Society of Economic Paleontologists and Mineralogists, Short Course, 1983, 10: 1-151.

[3] Baum G. R., Harris W. B., Dres P. E. Origin of Dolomite in the Eocene Castle Hayne Limestone, North Carolina. Journal of Sedimentary Petrology, 1985, 55(4): 506-517.

[4] Benway H. M., Mix A. C. Oxygen Isotopes, Upper-Ocean Salinity, and Precipitation Sources in the Eastern Tropical Pacific. Earth and Planetary Science Letters, 2004, 224(3–4): 493-507.

[5] Budd D. A. Cenozoic Dolomites of Carbonate Islands: Their Attributes and Origin. Earth-Science Reviews, 1997, 42(1–2): 1-47.

[6] Buggisch W., Keller M., Lehnert O. Carbon Isotope Record pf Late Cambrian to Early Ordovician Carbonates of the Argentine Precordillera. Palaeogeogr Palaeoclimatol Palaeoecol, 2003, 195(3–4): 357-373.

[7] Buschkuehle B. E., Machel H. G. Diagenesis and Paleofluid Flow in the Devonian Southesk-Cairn Carbonate Complex in Alberta, Canada. Mar. Petrol. Geol., 2002, 19(3): 219-227.

[8] Chen Q., Hu W. X., Li Q. Characteristics and Genesis of Dolomitization in Changxing and Feixianguan Formations in Panlongdong, Northeastern Sichuan Basin. Oil & Gas Geology, 2012, 33(1): 84-93.

[9] Cheng X. Z., Li P. P., Zou H. Y., . Chen^G. Geochemical Characteristics and Fluid Origin of the Changxing Formation Dolomitic Rock in the Xinglongchang Area of East Sichuan Basin. Acta Geologica Sinica, 2013, 87(7): 1031-1040.

[10] Delaygue G., Jouzel J., Dutay J. C. Oxygen 18-Salinity Relationship Simulated by an Oceanic General Circulation Model. Earth and Planetary Science Letters, 2000, 178(1–2): 113-123.

[11] Derry L. A., Kaufman A. J., Jacobsen S. B. Sedimentary Cycling and Environmental Chang in the Late Proterozoic: Evidence from Stable and Radiogenic Isotopes. Geochim. Cosmochim. Acta., 1992, 56: 1317-1329.

[12] Dickson J. A. D., Coleman M. L. Changes in Carbon and Oxygen Isotopic Composition during Limestone Diagenesis. Sedimentology, 2010, 27(1): 107-118.

[13] Dix G. R., Sharma S., Al-Aasm I. S., . Hydrothermal Dolomite in the Timiskaming Outlier, Central Canadian Shield: Proxy for Late Ordovician Tectonic Activity. Am. J. Sci., 2010, 310(5): 405-423.

[14] Dong S. F., Chen D. Z., Qing H. R. In Situ Stable Isotopic Constraints on Dolomitizing Fluids for the Hydrothermally-Originated Saddle Dolomites at Keping, Tarim Basin. Chin. Sci. Bull., 2013, 58(23): 2877-2882.

[15] Dong X., Zheng R. C., Wang J., . Reservoir Sedimentological Characteristics of the Upper Permian Changxing Formation in Kaijiang-Liangping Area. Acta Petrologica et Mineralogica, 2010, 29(1): 67-78.

[16] Driese S. G., Mora C. L. Physico-Chemical Environment of Pedogenic Carbonate Formation in Devonian Vertic Palaeosols, Central Appalachians, U.S.A.. Sedimentology, 1993, 40: 199-216.

[17] Eren M., Kaplan M. Y., Kadir S. Petrography, Geochemistry and Origin of Lower Liassic Dolomites in the Aydýncýk Area, Mersin, Southern Turkey. Turkish Journal of Earth Sciences, 2007, 16: 339-362.

[18] Fan J. S., Wu Y. S. Restudies on Permian Reefs in Eastern Sichuan, China. Oil & Gas Geology, 2002, 23(1): 12-18.

[19] Friedman I., O’Neil J. R. Compilation of Stable Isotope Fractionation Factors of Geochemical Interest, 1977.

[20] Fritz P., Smith D. G. W. The Isotopic Composition of Secondary Dolomites. Geochimica Cosmochimica Acta, 1970, 34: 1161-1173.

[21] Geske A., Zorlu J., Richter D. K., . Impact of Diagenesis and Low Grade Metamorphosis on Isotope (Δ²⁶Mg, Δ¹³C, Δ¹⁸O and ⁸⁷Sr/⁸⁶Sr) and Elemental (Ca, Mg, Mn, Fe and Sr) Signatures of Triassic Sabkha Dolomites. Chemical Geology, 2012, 332–333: 45-64.

[22] Gonfiantini R. Fritz P., Fontes J. C. Environmental Isotopes in Lake Studies. Handbook of Environmental Isotope Geochemistry, 1986, Amsterdam: Elsevier, 113-168.

[23] Haas J., Budai T., Gyori O., . Similarities and Differences in the Dolomitization History of Two Coeval Middle Triassic Carbonate Platforms, Balaton Highland, Hungary. Facies, 2014, 60: 581-602.

[24] Han X. T., Bao Z. Y., Xie S. Y. Origin and Geochemical Characteristics of Dolomites in the Middle Permian Formation, SW Sichuan Basin, China. Earth Science, 2016, 41(1): 167-176.

[25] Hitzman M., Allan J., Beaty D. Regional Dolomitization of the Waulsortian Limestone in Southeastern Ireland: Evidence of Large-Scale Fluid Flow Driven by the Hercynian Orogeny. Geology, 1998, 26: 547-550.

[26] Huang S. J., Qing H. R., Pei C. R., . Strontium Concentration, Isotope Composition and Dolomitization Fluids, in the Feixianguan Formation of Triassic, Eastern Sichuan of China. Acta Petrologica Sinica, 2006, 22: 2123-2132.

[27] Huang S. J., Huang Y., Lan Y. F., . A Comparative Study on Strontium Isotope Composition of Dolomites and Their Coeval Seawater in the Late Permian–Early Triassic,NE Sichuan Basin. Acta Petrologica Sinica, 2011, 27(12): 3831-3842.

[28] Hu Z. W., Huang S. J., Li Z. M., . Geochemical Characteristics of the Permian Changxing Formation Reef Dolomites, Northeastern Sichuan Basin, China. Petroleum Science, 2013, 10(1): 38-49.

[29] Hendy C. H., Wilson A. T. Palaeoclimatic Data from Speleothems. Nature, 1968, 216: 48-51.

[30] Hendy C. H. The Isotopic Geochemistry of Speleothems I. The Calculation of the Effects of Different Modes of Formation on the Isotopic Composition of Speleothems and Their Applicability as Palaeclimatic Indicators. Geochimica et Cosmochimica Acta, 1971, 35(8): 801-824.

[31] Jiang L., Cai C. F., Worden R. H., . Reflux Dolomitization of the Upper Permian Changxing Formation and the Lower Triassic Feixianguan Formation, NE Sichuan Basin, China. Geofluid, 2013, 13: 232-245.

[32] Kaufman A. J., Jacobsen S. R., Knoll A. H. The Vendian Record of Sr and C Isotopic Variations in Seawater: Implications for Tectonics and Paleoclimate. Earth Planet Sci. Lett., 1993, 120: 409-430.

[33] Kirmaci M. Z. Origin of Dolomite in the Late Jurassic Platform Carbonates, Bolkar Mountains, Central Taurides, Turkey: Petrographic and Geochemical Evidence. Chemie der Erde, 2013, 73: 383-398.

[34] Kyser T. K., James N. P., Bone Y. Shallow Burial Dolomitization and Dedolomitization of Cenozoic Cool-Water Limestones, Southern Australia: Geochemistry and Origin. Journal of Sedimentary Research, 2002, 72(1): 146-157.

[35] Land L. S. The Application of Stable Isotopes to Studies of the Origin of Dolomite and to Problems of Diagenesis of Clastic Sediments. Stable Isotopes in Sedimentary Geology, SEPM Short Course Notes, 1983, 10 4.

[36] Land L. S. The Origin of Massive Dolomite. Geol. Educ., 1985, 33: 112-125.

[37] Lei B. J., Qiang Z. T., Wen Y. C. Dolomitization of the Upper Permian Organic Reefs in Eastern Sichuan and its Adjacent Areas. Geological Review, 1994, 40(6): 535-543.

[38] Li P. C., Chen G. H., Zeng Q. S., . Genesis of Lower Ordovician Dolomite in Central Tarim Basin. Acta Sedimentologica Sinica, 2011, 29(5): 842-856.

[39] Li Q., Jiang S. Y. Trace and Rare Earth Element Characteristics in Fe-Mn Carbonates Associated with Stratiform Ag-Pb-Zn Mineralization from the Lengshuikeng Ore District, Jiangxi Province: Implications for Their Genesis and Depositional Environment. Journal of Earth Science, 2016, 27(4): 571-583.

[40] Li Y. C. Carbon and Oxygen Isotope Stratigraphy of the Upper Permian Changhsingian Limestone in Meishan Section D, Changxing, Zhejiang. Journal of Stratigraphy, 1998, 22(1): 36-41.

[41] Li Z., Goldstein R. H., Franseen E.K. Ascending Freshwater-Mesohaline Mixing: A New Scenario for Dolomitization. Journal of Sedimentary Research, 2013, 83: 277-283.

[42] Li Z., Goldstein R. H., Franseen E. K. Geochemical Record of Fluid Flow and Dolomitization of Carbonate Platforms: Ascending Freshwater-Mesohaline Mixing, Miocene of Spain, in Fundamental Controls on Fluid Flow in Carbonate: Current Workflows to Emerging Technologies, Geological Society of London. Special Publication, 2015, 406(1): 115-140.

[43] Li Z. M., Xu E. S., Fan M., . Geochemical Characteristics and Formation of Dolostones from the Changxing Formation at Puguang Gas Field in Sichuan Basin. Geochimica, 2010, 39(4): 371-380.

[44] Liu L. J., Jiang H. X., Wu Y. S., . Community Replacement Sequences and Paleoenvironmental Changes in Reef Areas of South China From Late Permian to Early Triassic Exemplified by Panlongdong Section in Northeastern Sichuan Basin. Science China: Earth Sciences, 2014, 57: 1093-1108.

[45] Ma Y. S., Mu C. L., Guo X. S., . Characteristics and Frame Work of the Changxingian Sedimentation in the North Eastern Sichuan Basin. Geological Review, 2006, 52(1): 25-29.

[46] Machel H. G. Shukla V., Baker P. A. Fluid Flow Direction during Dolomite Formation as Deduced from Trace Element Trends. Sedimentology and Geochemistry of Dolostones, 1988, 115-125

[47] Machel H. G., Cavell P. A. Low-Flux, Tectonically-Induced Squeegee Fluid Flow (“Hot Flash”) into the Rocky Mountain Foreland Basin. Bull can Petrol Geol, 1999, 47: 510-533.

[48] Machel H. G. Recrystallization versus Neomorphism, and the Concept of ‘Significant Recrystallization’ in Dolomite Research. Sedimentary Geology, 1997, 113: 161-168.

[49] Mazzullo S. J. Dolomitization of Periplatform Carbonates (Lower Permian, Leonardian), Midland Basin, Texas. Carbonates and Evaporites, 1994, 9(1): 95-112.

[50] Meng W. B., Wu H. Z., Li G. R., . Dolomitization Mechanisms and Influence on Reservoir Development in the Upper Permian Changxing Formation in Yuanba Area, Northern Sichuan Basin. Acta Petrologica Sinica, 2014, 30(3): 699-708.

[51] Meyers W. J., Lu F. H., Zachariah J. K. Dolomitization by Mixed Evaporative Brines and Freshwater, Upper Miocene Carbonate, Nijar, Spain. Sediment Res, 1997, 67(5): 898-912.

[52] Moore C. H., Druckman Y. Burial Diagenesis and Porosity Evolution, Upper Jurassic Smackover, Arkansas and Louisiana. American Association of Petroleum Geologists Bulletin, 1981, 65: 597-628.

[53] Qing H. R., Mountjoy E. W. Large-Scale Fluid Flow in the Middle Devonian Presqu’ile Barrier, Western Canada Sedimentary Basin. Geology, 1992, 20: 903-906.

[54] Qing H. R., Veizer J. Oxygen and Carbon Isotopic Composition of Ordovician Brachiopods: Implications for Coeval Seawater. Geochim Cosmochim Acta, 1994, 58(20): 4429-4442.

[55] Qing H. R., Mountjoy E. W. Formation of Coarsely Crystalline, Hydrothermal Dolomite Reservoirs in the Presqu’ile Barrier, Western Canada Sedimentary Basin. AAPG Bull., 1994, 78(1): 55-77.

[56] Rameil N. Early Diagenetic Dolomitization and Dedolomitization of Late Jurassic and Earliest Cretaceous Platform Carbonates: A Case Study from the Jura Mountains (NW Switzerland, E France). Sedimentary Geology, 2008, 212(1–4): 70-85.

[57] Rao C. P. Marine to Mixing Zone Dolomitization in Peritidal Carbonates: the Gordon Group (Ordovician), Mole Creek, Tasmania, Australia. Carbonates and Evaporites, 1990, 6(2): 153-178.

[58] Reinhold C. Multiple Episodes of Dolomitization and Dolomite Recrystallization during Shallow Burial in Upper Jurassic Shelf Carbonates: Eastern Swabian Alb, Southern Germany. Sedimentary Geology, 1998, 121(1): 71-95.

[59] Saller A. H., Dickson J. A. D., Boyd S. A. Cycle Stratigraphy and Porosity in Pennsylvanian and Lower Permian Shelf Limestones, Eastern Central Basin Platform. American Association of Petroleum Geologists Bulletin, 1994, 78(12): 1820-1842.

[60] Saller A. H., Henderson N. Distribution of Porosity and Permeability in Platform Dolomites: Insight from the Permian of West Texas. AAPG Bulletin, 1998, 82(8): 1528-1550.

[61] Saller A. H., Henderson N. Distribution of Porosity and Permeability in Platform Dolomites: Insight from the Permian of West Texas: Reply. AAPG Bullentin, 2001, 85: 530-532.

[62] Saller A. H. Paleozoic Dolomite Reservoir in the Permian Basin, SW USA: Stratigraphic Distribution, Porosity, Permeability and Production. The Geometry and Petrogenesis of Dolomite Hydrocarbon Reservoirs. Geological Society Special Publications, Geological Society of London, 2004, 235(1): 309-323.

[63] Sass E., Katz A. The Origin of Platform Dolomites: New Evidence. Am. J. Sci, 1982, 282(8): 1184-1213.

[64] Sheppard S. M. F., Schwarz H. P. Fractionation of Carbon and Oxygen Isotopes and Magnesium between Coexisting Metamorphic Calcite and Dolomite. Contributions to Mineralogy and Petrology, 1970, 26: 161-198.

[65] Spotl C. Carbonates in Upper Permian Evaporites of the Northern Calcareous Alps, Austria. Geologische Rundschau, 1992, 81(2): 309-321.

[66] Sofer Z., Gat J. R. The Isotope Composition of Evaporating Brines: Effect of the Isotopic Activity Ratio in Saline Solutions. Earth Planet Sci. Lett., 1975, 26(2): 179-186.

[67] Tucker M. E., Wright V. P. Carbonate Sedimentology, 1992, Oxford: Blackwell, 482.

[68] Veizer J., Hoefs J. The Nature of ¹⁸O/¹⁶O and ¹³C/¹²C Secular Trends in Sedimentary Carbonate Rocks. Geochim Cosmochim Acta, 1976, 40(11): 1387-1395.

[69] Wahlman G. P. Reflux Dolomite Crystal Size Variation in Cyclic Inner Ramp Reservoir Facies, Bromide Formation (Ordovician), Arkoma Basin, Southeastern Oklahoma. Sediment. Rec., 2010, 8: 4-9.

[70] Wang G. Q., Xia W. C. The Variation of Isotopes(C, O) and the Organism Extinction Event across the P/T Boundary in Ziyun Section, Guizhou Province. Earth Science Frontiers, 2000, 7(2): 339-344.

[71] Wang Y. G., Wen Y. C., Zhang F. Distribution Law of the Organic Reefs in Changxing Formation of Upper Permian in East Sichuan. Natural Gas Industry, 1998, 18(6): 10-15.

[72] Wang Y. S. The Reefs of Changxing Period and the Reef Gas Accumulation in Sichuan Basin. Mineral. Petrol., 1996, 16(2): 62-69.

[73] Wei G. Q., Chen G. S., Yang W., . Preliminary Study of the Boundary of Kaijiang-Liangping trough in Northeast Sichuan Basin and Its Characteristics. Oil & Gas Geology, 2006, 27(1): 99-107.

[74] Wilson E. N., Hardie L. A., Phillips O. M. Dolomitization Front Geometry, Fluid Flow Patterns, and the Origin of Massive Dolomite: The Triassic Latemar Buildup, Northern Italy. American Journal of Science, 1990, 209(7): 741-796.

[75] Wu Q., Peng J. N. Burial and Thermal Histories of Northeastern Sichuan Basin: A Case Study of Well Puguang 2. Petroleum Geology& Experiment, 2013, 35(2): 133-138.

[76] Wu S. Q., Zhu J. Q., Wang G. X., . Types and Origin of Cambrian–Ordovician Dolomites in Tarim Basin. Acta Petrologica Sinica, 2008, 24(6): 1390-1400.

[77] Wu Y. S., Fan J. S., Jin Y. G. Emergence of the Late Permian Changsingian Reefs at the End of the Permian. Acta Geologica Sinica, 2003, 77(3): 289-296.

[78] Wu Y. S., Jiang H. X., Liao T. P. Sea-Level Drops in the Permian–Triassic Boundary Section at Laolongdong, Chongqing, Sichuan Province. Acta Petrologica Sinica, 2006, 22(9): 2405-2412.

[79] Wu Y. S., Yang W., Jiang H. X., . Petrologic Evidence for Sea-Level Drop in Latest Permian in Jiangxi Province, China and its Meanings for the Mass Extinction. Acta Petrologica Sinica, 2006, 22(12): 3039-3046.

[80] Wu Y. S., Jiang H., Fan J. S. Evidence for Sea-Level Falls in the Permian–Triassic Transition in the Ziyun Area, South China. Geological Journal, 2010, 45(2–3): 170-185.

[81] Wu Y. Q., Wu Z. D. Diagenetic Modification of Dolomite in Middle Ordovician Carbonates, Taiyuan City Area, China. Sedimentary Geology, 1998, 116(1–2): 143-156.

[82] Ye Q. C., Mazzullo S. J. Dolomitization of Lower Permian Platform Facies, Wichita Formation, North Platform, Midland Basin, Texas. Carbonates and Evaporites, 1993, 8(1): 55-70.

[83] Zeebe R. E. Seawater^PH and Isotopic^Paleotemperatures of Cretaceous Oceans. Palaeogeography Palaeoclimatology Palaeoecology, 2001, 170(1–2): 49-57.

[84] Zhang B., Zheng R. C., Wang X. B., . Geochemical Characteristics and Diagenetic Systems of Dolomite Reservoirs of the Changxing Formation in the Eastern Sichuan Basin, China. Petroleum Science, 2012, 9(2): 141-153.

[85] Zhang T. T., Liu B., Qin S. The Origin of Permian and Triassic Dolostones in Northeastern Sichuan Province, China. Acta Scientiarum Naturalium Universitatis Pekinensis, 2008, 44(5): 799-809.

[86] Zhao R., Wu Y. S., Jiang H. X., . Origin Evidenced by Statistic Feature and Orientation Fabric in the Upper Permian Changxing Formation Dolostone of Panlongdong, Northeastern Sichuan. Acta Geologica Sinica, 2014, 88(6): 1093-1105.

[87] Zheng R. C., Hu Z. G., Feng Q. P., . Genesis of Dolomite Reservoir of the Changxing Formation of Upper Permian, Northeast Sichuan Basin. Mineral. Petrol., 2007, 27(4): 78-84.

[88] Zheng R. C., Geng W., Zheng C., . Genesis of Dolostone Reservoir of Feixianguan Formation in Low Er Triassic of Northeast Sichuan Basin. Acta Petrolei Sinica, 2008, 29(6): 815-821.

[89] Zheng R. C., Shi J. N., Luo A. J., . Comparative Study on Geochemical Behaviors of Dolomite Reservoirs in Northeast Sichuan Basin. Natural Gas Industry, 2008, 28(11): 16-21.

[90] Zheng R. C., Hu Z. G., Zheng C., . Geochemical Characteristics of Stable Isotopes in Paleokarst Reservoirs in Huanglong Formation in Northern Chongqing-Eastern Sichuan Area. Earth Science Frontiers, 2008, 15(6): 303-311.

[91] Zheng R. C., Luo P., Wen Q. B., . Characteristics of Sequence Based Lithofacies and Paleogeography and Prediction of Oolitic Shoal of the Feixianguan Formation in the Northeastern Sichuan. Acta Sedimentologica Sinica, 2009, 27(1): 1-8.

[92] Zheng R. C., Dang L. R., Zheng C., . Diagenetic System of Carbonate Reservoirs in Huanglong Formation from the East Sichuan to North Chongqing Area. Acta Petrolei Sinica, 2010, 31(2): 237-245.

[93] Zheng R. C., Dang L. R., Wen H. G., . Diagenesis Characteristics and System for Dolostone in Feixianguan Formation of Northeast Sichuan. Earth Science. Journal of China University of Geosciences, 2011, 36(4): 659-669.