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Petrographic and geochemical characteristics of dolomites in the Devonian Shogram Formation, Karakorum Ranges, North Pakistan


Affiliations
1 Department of Earth and Environmental Sciences, Bahria University, Islamabad, Pakistan
2 Department of Earth Sciences, Quaid-i-Azam University Islamabad, Islamabad 45320, Pakistan
3 Department of Geology, Abdul Wali Khan University, Mardan, Pakistan
 

Excellent outcrops of Devonian carbonate rocks are present in the Karakorum Ranges of North Pakistan that are highly dolomitized. The Devonian Shogram Formation comprises both matrix and cement dolomite. Petrographic studies revealed the texture of matrix dolomite as fine-grained anhedral dolomite (D1), medium-grained subhedral to anhedral dolomite (D2), medium-grained euhedral dolomite (D3) and coarse-grained anhedral dolomite (D4). The saddle cement dolomite phase of hydrothermal origin precipitated in vugs and fractures. The origin of various dolomitization phases has been interpreted based on petrographic associations, elemental and stable isotopes signatures of each phase. The first two phases of dolomitization are affiliated with the compaction flow of overlying shales based on evidence of low Fe and Mn content and isotopically light signatures of d 18O. The increase in burial resulted in the third phase of dolomite showing signatures of redox conditions and high depleted d 18O compared to the original marine signatures. The final phases of matrix dolomite and saddle dolomite cement are associated with tectonic activity in the Karakorum region, which brought the deep-source Mg-rich fluids along the Reshun Fault.
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  • Peyravi, M., Rahimpour-Bonab, H., Nader, F. H. and Kamali, M. R., Dolomitization and burial history of lower triassic carbonate reservoir-rocks in the Persian Gulf (Salman offshore field). Carbonates Evaporites, 2008, 30, 25–43.

  • Navarro-Ciurana, D., Corbella, M., Cardellach, E., Vindel, E., Gómez-Gras, D. and Griera, A., Petrography and geochemistry of fault-controlled hydrothermal dolomites in the Riópar area (Prebetic Zone, SE Spain). Mar. Pet. Geol., 2016, 71, 310–328.

  • Warren, J., Dolomite: occurrence, evolution and economically important associations. Earth Sci. Rev., 2000, 52, 1–81.

  • Davies, G. R. and Smith, L. B., Structurally controlled hydrothermal dolomite reservoir facies: an overview. AAPG Bull., 2006, 90, 1641–1690.

  • Machel, H. G., Concepts and models of dolomitization: a critical reappraisal. Geol. Soc., London, Spec. Publ., 2006, 235, 7–63.

  • Friedman, G. M., Terminology of crystallization textures and fabrics in sedimentary rocks. J. Sediment. Res., 1965, 35, 643–655.

  • Sibley, D. F. and Gregg, J. M., Classification of dolomite rock textures. J. Sediment. Res., 1987, 57, 967–975.

  • Lemennicier, Y., Le Fort, P., Lombardo, B., Pêcher, A. and Rolfo, F., Tectonometamorphic evolution of the central Karakorum (Baltistan, northern Pakistan). Tectonophysics, 1996, 260, 119–143.

  • Searle, M. P., Geological evolution of the Karakoram Ranges. Ital. J. Geosci., 2011, 130, 147–159.

  • Le Fort, P. and Gaetani, M., Introduction to the geological map of the western Central Karakorum, North Pakistan. Hindu Raj, Ghamubar and Darkot regions. 1 : 250,000. Geologica, 1998, 3, 3–57.

  • Calkins, J. A., Jamiluddin, S., Bhuyan, K. and Hussain, A., Geology and mineral resources of the Chitral-Partsan area, Hindu Kush Range, northern Pakistan (No. 80-837). US Govt. Print. Off.; for sale by the Distribution Branch, US Geological Service, 1980.

  • Dickson, J. A. D., Carbonate identification and genesis as revealed by staining. J. Sediment. Res., 1966, 36, 491–505.

  • Veizer, J., Chemical diagenesis of carbonates: theory and application of trace element technique. J. Sediment. Res., 1983, 265–300.

  • Humphrey, J. D. and Quinn, T. M., Coastal mixing zone dolomite, forward modeling, and massive dolomitization of platform-margin carbonates. J. Sediment. Res., 1989, 59, 438–454.

  • Gaetani, M., The Karakorum block in central Asia, from Ordovician to Cretaceous. Sediment. Geol., 1997, 109, 339–359.

  • Zanchi, A., Gaetani, M. and Poli, S., The rich gol metamorphic complex: evidence of separation between Hindu Kush and Karakorum (Pakistan). CR Acad. Sci., Ser II, 1997, 325, 877–882.

  • Dawans, J. M. and Swart, P. K., Textural and geochemical alternations in late Cenozoic Bahamian dolomites. Sedimentology, 1988, 35, 385–403.

  • Hou, M. C., Jiang, W. J., Xing, F. C., Xu, S. L., Liu, X. C. and Xiao, C., Origin of dolomites in the Cambrian (upper 3rd‐Furongian) formation, south‐eastern Sichuan Basin, China. Geofluids, 1993, 16, 856–876.

  • Machel, H. G., Concepts and models of dolomitization: a critical reappraisal. Geol. Soc. London, Spec. Publ., 2004, 235, 7–63.

  • Huang, S. J., Shi, H. and Mao, X. D., Diagenetic alteration of earlier Palaeozoic marine carbonate and preservation for the information of sea water. J. Chengdu Univ. Technol., 2003, 30, 9–18.

  • Machel, H. G. and Anderson, J. H., Pervasive subsurface dolomitization of the Nisku Formation in central Alberta. J. Sediment. Res., 1989, 59, 891–911.

  • Banner, J. L., Hanson, G. N. and Meyers, W. J., Water–rock interaction history of regionally extensive dolomites of the Burlington-Keokuk Formation (Mississippian): isotopic evidence. In Sedimentology and Geochemistry of Dolostones (eds Shukla, V. and Baker, P. A.), 1988.

  • Swart, P. K., The geochemistry of carbonate diagenesis: the past, present and future. Sedimentology, 2015, 62(5), 1233–1304.

  • Zheng, X., Arps, P. J. and Smith, R. W., Adsorption of Bacillus subtilis to minerals: effect on the flotation of dolomite and apatite. Process Metall., 1999, 9, 127–136.

  • Lorens, R. B., Sr, Cd, Mn and Co distribution coefficients in calcite as a function of calcite precipitation rate. Geochim. Cosmochim. Acta, 1981, 45, 553–561.

  • Montañez, I. P. and Read, J. F., Eustatic control on early dolomitization of cyclic peritidal carbonates: evidence from the Early Ordovician Upper Knox Group, Appalachians. Geol. Soc. Am. Bull., 1992, 104, 872–886.

  • Swart, P. K., Cantrell, D. L., Westphal, H., Handford, C. R. and Kendall, C. G., Origin of dolomite in the Arab-D reservoir from the Ghawar Field, Saudi Arabia: evidence from petrographic and geochemical constraints. J. Sediment. Res., 2005, 75, 476–491.

  • Swart, P. K., The geochemistry of carbonate diagenesis: the past, present and future. Sedimentology, 2015, 62, 1233–1304.

  • Radke, B. M. and Mathis, R. L., On the formation and occurrence of saddle dolomite. J. Sediment. Res., 1980, 50, 1149–1168.

  • Morrow, D. W., Diagenesis 2. Dolomite-part 2 dolomitization models and Ancient dolostones. Geosci. Can., 1982, 9, 95–107.

  • Morrow, D., Regional subsurface dolomitization: models and constraints. Geosci. Can., 1998, 25.

  • Saleem, M., Dolomitization in Devonian Shogram Formation, Chitral North Pakistan: multiple constraints from field analysis, petrography, geochemistry and diagenetic studies. Doctoral Dissertation, Quaid e Azam University, Pakistan, 2022.

  • Stauffer, K. W., Reconnaissance geology of the central Mastuj valley, Chitral State, Pakistan (No. 75-556), US Geological Survey, Chitral, 1975.

  • Popp, B. N., Anderson, T. F. and Sandberg, P. A., Textural, elemental, and isotopic variations among constituents in Middle Devonian limestones, North America. J. Sediment. Petrol., 1986, 56, 715–727.


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  • Petrographic and geochemical characteristics of dolomites in the Devonian Shogram Formation, Karakorum Ranges, North Pakistan

Abstract Views: 157  |  PDF Views: 102

Authors

Maryam Saleem
Department of Earth and Environmental Sciences, Bahria University, Islamabad, Pakistan
Faisal Rehman
Department of Earth Sciences, Quaid-i-Azam University Islamabad, Islamabad 45320, Pakistan
Abbas Ali Naseem
Department of Earth Sciences, Quaid-i-Azam University Islamabad, Islamabad 45320, Pakistan
Emadullah Khan
Department of Geology, Abdul Wali Khan University, Mardan, Pakistan
Syed Wasim Sajjad
Department of Earth Sciences, Quaid-i-Azam University Islamabad, Islamabad 45320, Pakistan
Zubair Ahmed
Department of Earth Sciences, Quaid-i-Azam University Islamabad, Islamabad 45320, Pakistan

Abstract


Excellent outcrops of Devonian carbonate rocks are present in the Karakorum Ranges of North Pakistan that are highly dolomitized. The Devonian Shogram Formation comprises both matrix and cement dolomite. Petrographic studies revealed the texture of matrix dolomite as fine-grained anhedral dolomite (D1), medium-grained subhedral to anhedral dolomite (D2), medium-grained euhedral dolomite (D3) and coarse-grained anhedral dolomite (D4). The saddle cement dolomite phase of hydrothermal origin precipitated in vugs and fractures. The origin of various dolomitization phases has been interpreted based on petrographic associations, elemental and stable isotopes signatures of each phase. The first two phases of dolomitization are affiliated with the compaction flow of overlying shales based on evidence of low Fe and Mn content and isotopically light signatures of d 18O. The increase in burial resulted in the third phase of dolomite showing signatures of redox conditions and high depleted d 18O compared to the original marine signatures. The final phases of matrix dolomite and saddle dolomite cement are associated with tectonic activity in the Karakorum region, which brought the deep-source Mg-rich fluids along the Reshun Fault.

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DOI: https://doi.org/10.18520/cs%2Fv123%2Fi4%2F583-591