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Petrological features of boseti mountains, a complex volcanic system in the axial portion of the main Ethiopian rift

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Abstract

A petrographical and chemical research carried out mainly for the rocks belonging to the 2nd cycle of volcanic activity of Boseti Mts., shows the predominance of the salic over the mafic and the intermediate products. The magmatic evolution, which chiefly took place in a thermodynamic environment with initial low\(P_{H_2 O} \) and\(f_{O_2 } \), has brought about subaluminiferous mugearitic types, also with trachytic affinity. Among peralkali-rhyolites, an anorthoclase fractionation can explain both their chemical variation and the production of pantelleritic liquids.

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References

  • Bailey, D. K., 1974,Origin of alkaline magmas as a result of anatexis: Melting in the deep crust. In:The Alkaline Rocks,Sørensen,H. Ed., p. 436–442, J. Wiley & Sons, Interscience Publishers, London.

    Google Scholar 

  • ————— andMacdonald, R., 1969,Alkali-feldspar fractionation trends and the derivation of peralkaline liquids. Am. J. Sci.,267, p. 242–248.

    Article  Google Scholar 

  • ————— and —————, 1970,Petrochemical features of mildly peralkaline (comenditic) rhyolite glasses from continents and ocean basins. Contrib. Min. Petr.,28, p. 340–351.

    Article  Google Scholar 

  • ————— andSchairer, J. A., 1966,The system Na 2O-Al2O3-SiO2 at 1 atmosphere and the petrogenesis of alkaline rocks. J. Petrol.,7, p. 114–170.

    Google Scholar 

  • ————— andSchairer, J. F., 1964,Feldspar-liquid equilibria in peralkaline liquids: the orthoclase effect. Am. J. Sci.,262, p. 1198–1206.

    Article  Google Scholar 

  • Baker, I., 1968,Intermediate oceanic volcanic rocks and the «Daly gap». Earth. Planet. Sci. Letters,4, p. 103–106.

    Article  Google Scholar 

  • Barberi, F., Borsi, S., Ferrara, G., Marinelli, G. andVaret, J., 1970,Relationship between tectonics and magmatology of the northern Afar (or Danakil) Depression. Phil. Trans. R. Soc. London, A267, p. 293–311.

    Google Scholar 

  • Biasint, A., Morbidelli, L., andPiccirillo, E. M., 1974,Lineamenti geomorfologici, strutturali e vulcanologici dei Monti Boseti (Rift Etiopico Principale). Geol. Rom. (in press).

  • Bowen, N. L., 1945,Phase equilibria bearing on the origin and differentiation of alkaline rocks. Am. J. Sci., Daly Volume,243, p. 75–89.

    Google Scholar 

  • Cann, J. R., 1968,Bimodal distribution of rocks from volcanic islands. Earth. Planet. Sci. Letters,4, p. 479–480.

    Article  Google Scholar 

  • Carmichael, I. S. E., 1962,Pantelleritic liquids and their phenocrysts. Mineral. Mag.,33, p. 86–113.

    Article  Google Scholar 

  • —————. andMacKenzie, W. S., 1963,Feldspar-liquid equilibria in pantellerites: an experimental study. Am. J. Sci.,261, p. 382–396.

    Article  Google Scholar 

  • Chayes, F., 1963,Relative abundance of intermediate members of the oceanic basalttrachyte association. J. Geophys. Res.,68, p. 1519–1534.

    Article  Google Scholar 

  • Cox, K. G., Gass, I. G., andMallick, D. I. J., 1970,The structural evolution and volcanic history of the Aden and Little Aden volcanoes. Q. J. Geol. Soc. London,124, p. 283.

    Article  Google Scholar 

  • Dakin, F., andGibson, I. L., 1971,Boseti Bariccia: a Quaternary pantelleritic volcano in the Main Ethiopian Rift. Bull. Geophys. Obs. Addis Ababa,13, p. 106–109.

    Google Scholar 

  • Dickinson, D. R., andGibson, I. L., 1972,Feldspar fractionation and anomalous87Sr/86Sr ratios in a suite of peralkaline silicic rocks. Bull. Geol. Soc. Am.,83, p. 231–240.

    Article  Google Scholar 

  • Di Paola, G. M., 1972,The Ethiopian Rift Valley (between 7°00′ and 8°40′ lat. North). Bull. Volc.,36-4, p. 517–560.

    Google Scholar 

  • Ernst, W. G., 1962,Synthesis, stability relations and occurrence of riebeckite and riebeckite-arfvedsonite solid solutions. J. Geol.,70, p. 951–980.

    Google Scholar 

  • Ewart, A., Taylor, S. R., andCapp A. C., 1968,Geochemistry of the pantellerites of Maior Island, New Zealand. Contr. Min. Petr.,17, p. 116–140.

    Article  Google Scholar 

  • Gass, I. G., andMallick, D. I. J., 1968,Jebel Khariz: an Upper Miocene strato volcano of comenditic affinity, on the South Arabian Coast. Bull. Volc.,32-1, p. 33–88.

    Article  Google Scholar 

  • —————, —————,, andCox, K. G., 1965,The Royal Society Volcanological Expedition to the South Arabian Federation and the Red Sea. Nature, Lond.,205, p. 952.

    Article  Google Scholar 

  • Gibson, I. L., 1967,Preliminary account of the volcanics geology of Fantale, Shoa, Ethiopia. Bull. Geophys. Obs. Addis Ababa,10, p. 59–67.

    Google Scholar 

  • —————, 1969,The structure and volcanic geology of an axial portion of the Main Ethiopian Rift. Tectonophysics,8, p. 561–565.

    Article  Google Scholar 

  • —————, 1972,The chemistry and petrogenesis of a suite of pantellerites from the Ethiopian Rift. J. Petrology,13, p. 31–44.

    Google Scholar 

  • Goulin, P., 1970,Seismic and gravity data from Afar in relation to surrounding area. Phil. Trans. Roy. Soc. London, A-267, p. 339–358.

    Google Scholar 

  • Harris, P. G., 1963,Comments on a paper by F. Chayes, «Relative abundance of intermediate members of the oceanic basalt-trachite association». J. Geophis. Res.,68, p. 5103–5107.

    Google Scholar 

  • Hieke-Merlin, O., 1950,I basalti dell’Africa Orientale. Mem. Ist. Geol. Univ. Padova,17, p. 1–40.

    Google Scholar 

  • —————, 1963,Le vulcaniti acide dell’Africa Orientale. Mem. Ist. Geol. Miner. Univ. Padova,18, p. 1–45.

    Google Scholar 

  • Justin-Visentin, E., Nicoletti, M., Tolomeo, L., andZanettin, B., 1974,Miocene and Pliocene volcanics of the Addis Ababa-Debra Berhan area: geo-petrographic and radiometric study. Bull. Volc., (in press).

  • King, B. C., 1970,Vulcanicity and Rift tectonics in East Africa. In:African Magmatism and Tectonics, p. 263–283, Oliver & Boyd, Edinburgh.

    Google Scholar 

  • Kuno, H., 1968,Differentiation of basalt magma. In:Basalts, Part 2, p. 623–688, Interscience Publishers, N. Y.

    Google Scholar 

  • Le Maitre, R. W., 1968,Chemical variations between and within volcanic rock series: a statistical approach. J. Petrology,9, p. 220–252.

    Google Scholar 

  • Macdonald, R., andBailey, D. K., 1972,The chemistry of the peralkaline oversaturated obsidians. U. S. Geol. Surv. Prof. Paper 440-N., Part 1.

  • —————, andGibson, I. L., 1969,Pantelleritic obsidians from the volcano Chabbi (Ethiopia). Contr. Min. Petr.,24, p. 239–244.

    Article  Google Scholar 

  • Makris, J., Menzel, H., andZimmermann, G., 1972,A preliminary interpretation of the gravity field of Afar, northeast Ethiopia. Tectonophysics,15, p. 31–41.

    Article  Google Scholar 

  • —————, —————, —————, andWohlemberg, J., 1969,Crustal and Upper Mantle structure of the Ethiopian Rift derived from seismic and gravity data. Zeitsch. für Geophys.,36, p. 387–391.

    Google Scholar 

  • Mohr, P. A., 1962,The Ethiopian Rift System. Bull. Geophys. Obs. Addis Ababa,5, p. 33–62.

    Google Scholar 

  • Mohr, P. A., 1967,The Ethiopian Rift System. Bull. Geophys. Obs. Addis Ababa,11, p. 1–65.

    Google Scholar 

  • —————, 1974,Some new radiometric ages bearing on the evolution of the Main Ethiopian Rift, East of Addis Ababa. Smiths. Astr. Obs. Spec. Pap. 358, A, p. 1–9.

    Google Scholar 

  • Morbidelli, L., Nicoletti, M., Petrucciani, C., andPiccirillo, E. M., 1974,Ethiopian southeastern plateau and related escarpment: K/Ar ages of the main volcanic events (Main Ethiopian Rift from 8°10′ to 9°00′ Lat. N.). Symp. on the Afar region of Ethiopia and Related problems, Bad Bergzabern, April 1974; Afar Monograph,A. Pilger Ed., Klausthal, W. Germany (in press).

  • —————, andPiccirillo, E. M., 1973,Tectonics and volcanism in the Main Ethiopian Rift (Preliminary report). Boll. Soc. Geol. It.,92, p. 273–286.

    Google Scholar 

  • Muir, I. D., andTilley, C. E., 1961,Mugearites and their place in alkali igneous rock series. J. Geol.,69, p. 186–203.

    Google Scholar 

  • Nesbitt, R. W., andHamilton, D. L., 1970,Crystallization of an alkali olivine basalt under controlled Po2conditions. Earth. Planet. Sci. Letters,3, p. 309–315.

    Google Scholar 

  • Nicholls, J., andCarmichael, I. S. E., 1969,Peralkaline acid liquids: a petrological study. Contr. Min. Petr.,20, p. 268–294.

    Article  Google Scholar 

  • Noble, D. C., 1968,Systematic variation of major elements in comendite and pantellerite glass. Earth. Planet. Sci. Letters,4, p. 167–172.

    Article  Google Scholar 

  • —————, andPeck, L. C., 1967,Loss of halogens from crystallized and glassy silicic volcanic rocks. Geo. and Cosmoch. Acta,31, p. 215–224.

    Article  Google Scholar 

  • Searle, R. C., andGouin, P., 1972,A gravity survey of the central part of the Ethiopian Rift Valley. Tectonophysics,5, p. 41–52.

    Article  Google Scholar 

  • Sørensen, H., 1974,Glossary of alkaline and related rocks. In:The Alkaline rocks. J. Wiley & Sons, Interscience Publishers, London.

    Google Scholar 

  • Thompson, R. N., andMacKenzie, W. S., 1967,Feldspar-liquid equilibria in peralkaline acid liquids: an experimental study. Am. J. Sci.,265, p. 714–734.

    Article  Google Scholar 

  • Tuttle, O. F., andBowen, N. L., 1958,Origin of granite in the light of experimental studies in the system NaAlSi3O8-KAlSi3O8-SiO2-H2O. Geol. Soc. Am. Mem.,74, p. 1–153.

    Google Scholar 

  • Wager, L. R., andDeer, W. A., 1939,Geologic investigation in East Greenland. Part III: The petrology of the Skaergaard intrusion. Kangerdlng. Medd. Grønland,105, p. 1–352.

    Google Scholar 

  • Zanettin, B., andJustin-Visentin, E., 1973,Serie di vulcaniti etiopiche I: La serie dell’altipiano etiopico centro-orientale. Boll. Soc. Geol. It.,91, p. 313–327.

    Google Scholar 

  • -----, and -----, 1974,Serie di vulcaniti etiopiche II: La serie della scarpata dell’altipiano etiopico centro-orientale. Boll. Soc. Geol. It. (in press).

  • Zies, E. G., 1960,Chemical analyses of two pantellerites. J. Petrol.,1, p. 304–308.

    Google Scholar 

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Brotzu, P., Morbidelli, L., Piccirillo, E.M. et al. Petrological features of boseti mountains, a complex volcanic system in the axial portion of the main Ethiopian rift. Bull Volcanol 38, 206–234 (1974). https://doi.org/10.1007/BF02597811

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