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Fluid inclusion studies of the Kenticha rare-element granite-pegmatite, Southern Ethiopia

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Abstract

In the Kenticha area, a series of barren to rare metal-bearing pegmatites intruded into the Neoproterozoic Adola Belt. The pegmatites host world-class Nb and Ta deposits and significant Li and Be reserves. In this contribution, fluid inclusion data and feldspar geothermometry have been combined to define the crystallization condition of the Kenticha rare-metal pegmatite. Primary and complex assemblages of secondary fluid inclusions representing episodic fluid circulations have been identified in quartz and spodumene. A primary aqueous-carbonic fluid of low salinity aqueous solution with liquid and vapour CO2 phases, secondary carbonic fluid rich and carbonic-only fluids, and multiple generations of secondary aqueous inclusions that represent sub-solidus hydrothermal circulation have been identified. All aqueous inclusions were homogenized into the liquid phase between 100 and 290 °C. Aqueous-carbonic inclusions were homogenized, usually via a critical transition [Th(LV → SCF)] between 241 and 397 °C, or less commonly, via a dew-point transition [Th (LV → V)] between 213 and 264 °C. Crystallization of the rare-element pegmatite is certainly associated with the late-stage magmatic or early hydrothermal low-salinity aqueous-carbonic fluid that homogenizes to critical conditions. A combination of microthermometric data and existing experimentally determined solidus from flux and volatile bearing haplogranite suggests exsolution of fluids from hydrous silicate melt, perhaps during crystallization of the aplitic layer. The fluids were then trapped and isobarically cooled along a reasonable geothermal gradient within the pegmatite unit down to a temperature of around 397 °C.

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References

  • Ackerman L, Zachariáš J, Pudilová M (2007) P-T and fluid evolution of barren and lithium pegmatites from Vlastějovice, Bohemian Massif, Czech Republic. Int J Earth Sci 96:623–638. https://doi.org/10.1007/s00531-006-0133-3

    Article  Google Scholar 

  • Allen A, Tadesse G (2003) Geological setting and tectonic subdivision of the Neoproterozoic orogenic belt of Tuludimtu, western Ethiopia. J Afr Earth Sci 36:329–343. https://doi.org/10.1016/S0899-5362(03)00045-9

    Article  Google Scholar 

  • Anderson AJ, Clark AH, Gray S (2001) The occurrence and origin of zabuyelite (Li2co3) in spodumene-hosted fluid inclusions: implications for the internal evolution of rare-element granitic pegmatites. Can Miner 39:1513–1527

    Article  Google Scholar 

  • Ayllón F, Bakker RJ, Warr LN (2003) Re-equilibration of fluid inclusions in diagenetic-anchizonal rocks of the Ciñera-Matallana coal basin (NW Spain). Geofluids 3:49–68. https://doi.org/10.1046/j.1468-8123.2003.00048.x

    Article  Google Scholar 

  • Bakker RJ (2003) Package FLUIDS 1. Computer programs for analysis of fluid inclusion data and for modelling bulk fluid properties. Chem Geol Geol 194:3–23

    Article  Google Scholar 

  • Bakker RJ (2018) AqSo_NaCl: computer program to calculate p-T-V-x properties in the H2O-NaCl fluid system applied to fluid inclusion research and pore fluid calculation. Comput Geosci 115:122–133. https://doi.org/10.1016/j.cageo.2018.03.003

    Article  Google Scholar 

  • Bakker RJ, Diamond L (2006) Estimation of volume fractions of liquid and vapor phases in fluid inclusions, and definition of inclusion shapes. Am Miner 91:635–657

    Article  Google Scholar 

  • Bekele B (2020) Genesis and Evolution of Kenticha Rare-Element Granite-Pegmatite, Southern Ethiopia. PhD Thesis. Indian Institute of Technology Roorkee, Roorkee, India.

  • Bekele B, Sen AK (2020) The mineral chemistry of gahnite, garnet and columbite-group minerals (CGM): implications for genesis and evolution of the Kenticha Rare-element granite-pegmatite, Adola, Ethiopia. J Afr Earth Sci 162:103691. https://doi.org/10.1016/j.jafrearsci.2019.103691

    Article  Google Scholar 

  • Benisek A, Kroll H, Cemic L (2004) New developments in two-feldspar thermometry. Am Miner 89:1496–1504

    Article  Google Scholar 

  • Beraki WH, Bonavia F, Getachew T, Schmerold R, Tarekegn T (1989) The Adola Fold and Thrust Belt, southern Ethiopia: a re-examination with implications for Pan-African evolution. Geol Mag 126(06):647–657. https://doi.org/10.1017/S0016756800006944

    Article  Google Scholar 

  • Beurlen H, Da Silva MRR, De De Castro C (2000) Fluid origin and evolution during the formation of rare-element pegmatites from the borborema province. Northeast Brazil Rev Bras Geociências 30:331–336

    Article  Google Scholar 

  • Beurlen H, Da Silva MRR, De Castro C (2001) Fluid inclusion microthermometry in Be-Ta-(Li-Sn)-bearing pegmatites from the Borborema Province, Northeast Brazil. Chem Geol 173:107–123. https://doi.org/10.1016/S0009-2541(00)00270-9

    Article  Google Scholar 

  • Bisrat Y, Reimold WU, Armstrong R, Koeberl C, Anhaeusser CR, Phillips D (2002) The tectonostratigraphy, granitoid geochronology and geological evolution of the Precambrian of southern Ethiopia. J Afr Earth Sci 34:57–84

    Article  Google Scholar 

  • Bisrat Y, Reimold WU, Anhaeusser CR, Koeberl C (2003) Geochemistry of the mafic rocks of the ophiolitic fold and thrust belts of southern Ethiopia: constraints on the tectonic regime during the Neoproterozoic (900–700 Ma). Precambrian Res 121:157–183

    Article  Google Scholar 

  • Brown WL, Parsons I (1981) Towards a more practical two-feldspar geothermometer. Contrib Miner Pet 76:369–377

    Article  Google Scholar 

  • Cameron EN, Rowe RB, Weis PL (1953) Fluid inclusions in Beryl and Quartz from Pegmatites of the Middletown District, Connecticut. Am Miner J Earth Planet Mater 38(3–4):218–262

    Google Scholar 

  • Canet C, Franco SI, Prol-Ledesma RM, González-Partida E, Villanueva-Estrada RE, Prol-Ledesma RM, González-Partida E, Villanueva-Estrada RE (2011) A model of boiling for fluid inclusion studies: application to the Bolaños Ag-Au-Pb-Zn epithermal deposit, Western Mexico. J Geochem Explor 110(2):118–125. https://doi.org/10.1016/j.gexplo.2011.04.005

    Article  Google Scholar 

  • Černý P (1991) Rare-element granitic pegmatites. Part I: anatomy and internal evolution of pegmatite deposits. Geosci Can 18(2):49–67

    Google Scholar 

  • Chen HS (1972) The thermodynamics and composition of carbon dioxide hydrate. Syracuse University, Syracuse, New York

    Google Scholar 

  • Darling RS (1991) An extended equation to calculate NaCl contents from final clathrate melting temperatures in H2O-CO2-NaCl fluid inclusions: implications for P-T isochore location. Geochim Cosmochim Acta 55(12):3869–3871

    Article  Google Scholar 

  • Diamond LW (2003) Glossary: terms and symbols used in fluid inclusion studies. Fluid Incl Anal Interpret 32:363–372

    Google Scholar 

  • Ebadi A, Johannes W (1991) Beginning of melting and composition of first melts in the system Qz-Ab-Or-H2O-CO2. Contrib Miner Petrol 106:286–295

    Article  Google Scholar 

  • Elkins LT, Grove TL (1990) Ternary feldspar experiments and thermodynamic models. Am Miner 75:544–559

    Google Scholar 

  • Fall A, Tattitch B, Bodnar RJ (2011) Combined microthermometric and Raman spectroscopic technique to determine the salinity of H2O-CO2-NaCl fluid inclusions based on clathrate melting. Geochim Cosmochim Acta 75:951–964. https://doi.org/10.1016/j.gca.2010.11.021

    Article  Google Scholar 

  • Fritz H, Abdelsalam M, Ali KA, Bingen B, Collins AS, Fowler AR, Ghebreab W, Hauzenberger CA, Johnson PR, Kusky TM, Macey P, Muhongo S, Stern RJ, Viola G (2013) Orogen styles in the East African Orogen: a review of the Neoproterozoic to Cambrian tectonic evolution. J Afr Earth Sci 86:65–106. https://doi.org/10.1016/j.jafrearsci.2013.06.004

    Article  Google Scholar 

  • Fuertes-fuente M, Martin-izard A, Boiron MC, Viñuela JM (2000) P-T Path and fluid evolution in the Franqueira granitic pegmatite, central Galicia, Northwestern Spain. Can Miner 38:1163–1175

    Article  Google Scholar 

  • Fuertes-Fuente M, Martin-Izard A (1998) The Forcarei Sur rare-element granitic pegmatite field and associated mineralization, Galicia, Spain. Can Miner 36:303–325

    Google Scholar 

  • Goldstein RH (2001) Fluid inclusions in sedimentary and diagenetic systems. Lithos 55:159–193

    Article  Google Scholar 

  • Goldstein RH, Reynolds T (1994) Systematics of fluid inclusions in diagenetic minerals. SEPM Short Course 31:199

    Google Scholar 

  • Green NL, Usdansky SI (1986) Ternary-feldspar mixing relations and thermobarometry. Am Miner 71(9–10):1100–1108. https://doi.org/10.1007/BF00307762

    Article  Google Scholar 

  • Hailu W, Schandelmeier H (1996) Tectonic evolution of the Neoproterozoic Adola Belt of southern Ethiopia: evidence for a Wilson Cycle process and implications for oblique plate collision. Precambrian Res 77:179–210. https://doi.org/10.1016/0301-9268(95)00054-2

    Article  Google Scholar 

  • Jahns RH, Burnham CW (1969) Experimental studies of pegmatite genesis: l, a model for the derivation and crystallization of granitic pegmatites. Econ Geol 68:843–864

    Article  Google Scholar 

  • Jiao S, Guo J (2011) Application of the two-feldspar geothermometer to ultrahigh-temperature (UHT) rocks in the Khondalite belt, North China craton and its implications. Am Miner 96:250–260. https://doi.org/10.2138/am.2011.3500

    Article  Google Scholar 

  • Keppler H (1989) The influence of the fluid phase composition on the solidus temperatures in the haplogranite system NaAlSi3O8 - KAlSi3O8 - SiO2 - H2O - CO2. Contrib Miner Petrol 102:321–327

    Article  Google Scholar 

  • Kozyrev V, Girma K, Bekele WM, Teweldemedhin T (1982) Regional geological and exploration work for gold and other minerals in the Adola gold fields. Internal unpublished report, Ethiopian Mineral Resource Development Corp, Ministry of Mines and Energy. Addis Ababa

  • Küster D (2009) Granitoid-hosted Ta mineralization in the Arabian-Nubian Shield: ore deposit types, tectono-metallogenetic setting and petrogenetic framework. Ore Geol Rev 35:68–86. https://doi.org/10.1016/j.oregeorev.2008.09.008

    Article  Google Scholar 

  • Küster D, Romer RL, Tolessa D, Zerihun D, Bheemalingeswara K, Melcher F, Oberthür T (2009) The Kenticha rare-element pegmatite, Ethiopia: internal differentiation, U-Pb age and Ta mineralization. Miner Depos 44:723–750. https://doi.org/10.1007/s00126-009-0240-8

    Article  Google Scholar 

  • Lamadrid HM, Lamb WM, Santosh M, Bodnar RJ (2014) Raman spectroscopic characterization of H2O in CO2-rich fluid inclusions in granulite facies metamorphic rocks. Gondwana Res 26:301–310. https://doi.org/10.1016/j.gr.2013.07.003

    Article  Google Scholar 

  • London D (1986) Magmatic-hydrothermal transition in the Tanco rare-element pegmatite: evidence from fluid inclusions and phase-equilibrium experiments. Am Miner 71:376–395

    Google Scholar 

  • London D (1992) The Application of experimental petrology to the genesis and crystallization of granitic pegmatites. Can Miner 30:499–540

    Google Scholar 

  • London D, Kontak DJ (2012) Granitic pegmatites: scientific wonders and economic bonanzas. Elements 8:257–261. https://doi.org/10.2113/gselements.8.4.257

    Article  Google Scholar 

  • London D, Morgan GB (2012) The pegmatite puzzle. Elements 8:263–268. https://doi.org/10.2113/gselements.8.4.263

    Article  Google Scholar 

  • London D, Spooner ETC, Roedder E (1982) Fluid-solid inclusions in spodumene from the Tanco pegmatite, Bernic Lake. Manitoba Carnegie Inst Washingt Year b 81:334–339

    Google Scholar 

  • Manning DAC (1983) Chemical variation in garnets from aplites and pegmatites, peninsular Thailand. Miner Mag 47:353–358

    Article  Google Scholar 

  • Nabelek PI, Ternes K (1997) Fluid inclusions in the Harney Peak Granite, Black Hills, South Dakota, USA: implications for solubility and evolution of magmatic volatiles and crystallization of leucogranite magmas. Geochim Cosmochim Acta 61:1447–1465. https://doi.org/10.1016/S0016-7037(97)00006-9

    Article  Google Scholar 

  • Nabelek PI, Russ-Nabelek C, Denison JR (1992) The generation and crystallization conditions of the Proterozoic Harney Peak Leucogranite, Black Hills, South Dakota, USA: petrologic and geochemical constraints. Contrib Miner Petrol 110:173–191. https://doi.org/10.1007/BF00310737

    Article  Google Scholar 

  • Nabelek PI, Whittington AG, Sirbescu MLC (2010) The role of H2O in rapid emplacement and crystallization of granite pegmatites: resolving the paradox of large crystals in highly undercooled melts. Contrib Miner Petrol 160:313–325. https://doi.org/10.1007/s00410-009-0479-1

    Article  Google Scholar 

  • Pouchou JL, Pichoir F (1991) Quantitative analysis of homogeneous or stratified microvolumes applying the model “PAP.” In: Heinrich KFJ, Newbury DE (eds) Electron probe quantitation. Springer, Boston, MA

    Google Scholar 

  • Roedder E (1963) Studies of fluid inclusions II: freezing data and thier interpretation. Econ Geol 58(2):167–208

    Article  Google Scholar 

  • Roedder E (1981) Origin of fluid inclusion and changes that occur after trapping. In: Hollister LS, Crawford ML (eds) Short course handbook-fluid inclusion: application gto petrology. Mineralogical Association of Canada, Reston, USA

    Google Scholar 

  • Roedder E (1984) Fluid inclusions, reviews in mineralogy. Miner Soc Am 12:646

    Google Scholar 

  • Roedder E, Bodnar RJ (1980) Geologic pressure determinations from fluid inclusion studies. Annu Rev Earth Planet Sci 8:263–301

    Article  Google Scholar 

  • Rudnick RL, Gao S (2003) Composition of the continental crust. Treatise Geochem 3:1–64

    Google Scholar 

  • Schmidt C, Bodnar RJ (2000) Synthetic fluid inclusions: XVI. PVTX properties in the system H2O-NaCl-CO2 at elevated temperatures, pressures, and salinites. Geochim Cosmochim Acta 64:3853–3869. https://doi.org/10.1016/S0016-7037(00)00471-3

    Article  Google Scholar 

  • Shelton KL, Orville PM (1980) Formation of synthetic fluid inclusions in natural quartz. Am Miner 65:1233–1236

    Google Scholar 

  • Shepherd TJ, Ranbin AH, Alderton DHM, (1985) A practical guide to fluid inclusion studies. Glasgow and London (Blackie). Mineralogical magazine, London.

  • Sirbescu M-LC, Nabelek PI (2003) Crystallization conditions and evolution of magmatic fluids in the Harney Peak Granite and associated pegmatites, Black Hills, South Dakota — evidence from fluid inclusions. Geochim Cosmochim Acta 67:2443–2465. https://doi.org/10.1016/S0016-7037(02)01408-4

    Article  Google Scholar 

  • Solomon T, Zarihun D (1996) Composition, fractional trend and zoning accretion of the columbite-tantalite group of mineral in the Kenticha rare-metal field (Adola, Southern Ethiopia). J Afr Earth Sci 23:411–431

    Article  Google Scholar 

  • Solomon T, Zerihun D (1996) Composition, fractionation trend and zoning accretion of the columbite-tantalite group of minerals in the Kenticha rare-metal field (Adola, southern Ethiopia). J Afr Earth Sci 23:411–431. https://doi.org/10.1016/S0899-5362(97)00010-9

    Article  Google Scholar 

  • Steele-MacInnis M (2018) Fluid inclusions in the system H2O-NaCl-CO2: an algorithm to determine composition, density and isochore. Chem Geol 498:31–44. https://doi.org/10.1016/j.chemgeo.2018.08.022

    Article  Google Scholar 

  • Stern RJ, Dawoud AS (1991) Late precambrian (740 Ma), charnokite, enderbite, and granite from Jebel Moya, Sudan: a link between the Mozambique Belt and the Arabian-Nubian Shield. J Geol 99:648–659

    Article  Google Scholar 

  • Stern RJ, Ali KA, Abdelsalam MG, Wilde SA, Zhou Q (2012) U-Pb zircon geochronology of the eastern part of the Southern Ethiopian Shield. Precambrian Res 206–207:159–167. https://doi.org/10.1016/j.precamres.2012.02.008

    Article  Google Scholar 

  • Sterner SM, Bodnar RJ (1984) Synthetic fluid inclusions in natural quartz I. Compositional types synthesized and applications to experimental geochemistry. Geochim Cosmochim Acta 48:2659–2668

    Article  Google Scholar 

  • Stormer JCJ (1975) A practical two-feldspar geothermometer. Am Miner 60:667–674

    Google Scholar 

  • Tadesse S (2001) Geochemistry of the pegmatitic rocks and minerals in the Kenticha Belt, Southern Ethiopia: implication to geological setting. Gondwana Res 4:97–104. https://doi.org/10.1016/S1342-937X(05)70658-4

    Article  Google Scholar 

  • Tadesse Y, Adachi M, Takeuchi M (2004) P-T conditions of metamorphism in the Neoproterozoic rocks of the Negele area, Southern Ethiopia. Gondwana Res 7:489–500. https://doi.org/10.1016/S1342-937X(05)70800-5

    Article  Google Scholar 

  • Thiery R, van den Kerkhof AM, Dubessy J (1994) VX properties of CO2-CH4 and CO2-N2 fluid inclusions: modelling for T < 31°C and P < 400 bars. Eur J Miner 6:753–771

    Article  Google Scholar 

  • Touret JLR (2001) Fluids in metamorphic rocks. Lithos 55:1–25

    Article  Google Scholar 

  • Trumbull RB (1995) Mineralogy petrology a fluid inclusion study of the Sinceni rare-element pegmatites of Swaziland. Miner Petrol 55:85–102

    Article  Google Scholar 

  • Tsige L (2006) Metamorphism and gold mineralization of the Kenticha-Katawicha area: Adola belt, southern Ethiopia. J African Earth Sci 45:16–32. https://doi.org/10.1016/j.jafrearsci.2006.01.002

    Article  Google Scholar 

  • Vallance J, Fontboté L, Chiaradia M, Markowski A, Schmidt S, Vennemann T (2009) Magmatic-dominated fluid evolution in the Jurassic Nambija gold skarn deposits (southeastern Ecuador). Miner Depos 44(4):389–413. https://doi.org/10.1007/s00126-009-0238-2

    Article  Google Scholar 

  • van den Kerkhof AM, Hein UF (2001) Fluid inclusion petrography. Lithos 55:27–47

    Article  Google Scholar 

  • van den Kerkhof AM, Thiéry R (2001) Carbonic inclusions. Lithos 55:49–68

    Article  Google Scholar 

  • Veksler IV, Thomas R (2002) An experimental study of B-, P- and F-rich synthetic granite pegmatite at 0.1 and 0.2 GPa. Contrib Miner Petrol 143:673–683. https://doi.org/10.1007/s00410-002-0368-3

    Article  Google Scholar 

  • Vityk MO, Bodnar RJ (1995) Textural evolution of synthetic fluid inclusions in quartz during reequilibration, with applications to tectonic reconstruction. Contrib Miner Petrol 121:309–323. https://doi.org/10.1007/BF02688246

    Article  Google Scholar 

  • Vityk MO, Bodnar RJ, Schmidth CS, Schmidt CS (1994) Fluid inclusions as tectonothermobarometrs: relation between pressure-temperature history and reequilibration morphology during crustal thickening. Geology 22:731–734

    Article  Google Scholar 

  • Wen S, Nekvasil H (1994) SOLVCALC: an interactive graphics program package for calculating ternary feldspar solvus and two-feldspar geothermometry. Comput Geosci 20:1025–1040

    Article  Google Scholar 

  • Whitworth MP, Rankin AH (1989) Evolution of fluid phases associated with lithium pegmatites from SE Ireland. Mineral Mag 53:271–284

    Article  Google Scholar 

  • Wilkinson JJ (2001) Fluid inclusions in hydrothermal ore deposits. Lithos 55:229–272

    Article  Google Scholar 

  • Wood SA, Williams-jones AE (1993) Theoretical studies of the alteration of spodumene, petalite, eucryptite and pollucite in granitic pegmatites: exchange reactions with alkali feldspars. Contrib Miner Pet. https://doi.org/10.1007/BF00307760

    Article  Google Scholar 

  • Yihunie T, Adachi M, Takeuchi M (2004) P-T Conditions of Metamorphism in the Neoproterozoic Rocks of the Negele Area Southern Ethiopia. Gondwana Res 7(2):489–500. https://doi.org/10.1016/S1342-937X(05)70800-5

    Article  Google Scholar 

  • Zerihun D, Garbarino C, Valera R (1995) Granite pegmatite system in Kenticha (Adola, Sidamo, Ethiopia) rare-metal pegmatite belt: pegtrochemistry regional pegmatite zoning and classfication. SENET Ethiop J Sci 18:119–148

    Google Scholar 

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Acknowledgements

The authors are grateful to Dr. R. Krishnamurthi, Department of Earth Sciences, IIT Roorkee, India for permitting them access to the microthermometery facilities. We thank Mr. Kamlesh Kumar Meena for assisting during the Microthermometry lab work. The support provided by the Ethiopian Mineral, Petroleum and Biofuel Corporation (EMPBC) during the fieldwork deserves special gratitude. Mr. Mathios G/Wold from EMPBC is thankful for his support during the fieldwork.

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  1. Department of Earth Sciences, Indian Institute of Technology Roorkee, Roorkee, India

    Barsisa Bekele & Amit Kumar Sen

  2. Department of Earth Sciences, Wollega University, Nekemte, Ethiopia

    Barsisa Bekele

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Bekele, B., Sen, A.K. Fluid inclusion studies of the Kenticha rare-element granite-pegmatite, Southern Ethiopia. Acta Geochim 41, 926–946 (2022). https://doi.org/10.1007/s11631-022-00554-x

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