Impact of weathering on the chemical balance of the diatexites from the Edough Massif (Annaba, NE Algeria)
DOI:
https://doi.org/10.3989/egeol.40612.158Keywords:
Weathering, CIA, CIW, IFRAIS, diatexites, EdoughAbstract
The studied section, located on the eastern part of the Edough massif (region of Annaba, Algeria), is characterized by a Mediterranean climate and the area is one of the most humid of Algeria (precipitation between 750 and 1200 mm/year). It consists of diatexites with homogeneous petrographic and metamorphic facies. The primary minerals are quartz, feldspar, oligoclase and biotite whereas weathering products are mostly represented by illite and montmorillonite. Although all samples comprise the same mineral composition, due to changes in the mode, the chemistry of this diatexites is very heterogeneous. The chemical analyses of the rocks reveal a progressive evolution in the composition in terms of gains and losses in Ca, Na, K, Fe, Mg and in trace elements. The values of the Chemical Index of Change (CIA = 62.79 - 68.32, of the Chemical index of Weathering (CIW = 63.92 - 70.79), the Freshness Index (IFRAIS = 76 - 46.35) and the high value of the loss of ignition (L.O.I > 2%) as well as the Rb/Sr ratio >1 indicate that the distribution of the chemical elements along the section is entirely controlled by weathering (bisiallitisation alteration type) during a long time.
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Ahmed Said, Y.; Leake, B.E. & Rogers, G. (1993). The petrology, geochemistry and petrogenesis of the Edough igneous rocks, Annaba, NE Algeria. Journal of African Earth Sciences, 17(1): 111-123. http://dx.doi.org/10.1016/0899-5362(93)90027-N
Baldeyrou, A.; Vidal O. & Fritz B. (2003). Etude expérimentale des transformations de phases dans un gradient thermique:application au granite de Soultz-sous-Forêts, France. Comptes Rendus Géoscience, 335(4): 371-380. http://dx.doi.org/10.1016/S1631-0713(03)00056-7
Gardner, L.R. (1980). Mobilization of Al and Ti during rock weathering isovolumetric geochemical evidence. Chemical Geology, 30: 151-165. doi:10.1016/0009-2541(80)90122-9 http://dx.doi.org/10.1016/0009-2541(80)90122-9
Gleizes, G.; Bouleton, J.; Bossière, G. & Collomb, P. (1988). Données lithologiques et pétrostructurales nouvelles sur le Massif cristallophyllien de l'Edough (Est Algérien). Comptes Rendus de l'Académie des Sciences, Paris, series II, 306: 1001-1008.
Grabe-Schönberg, C.D. (1993). Simultaneous determination of thirty-seven trace elements in twenty eight international rock standards by ICP-MS. Geostandards Newsletter, 17(1): 81-98. http://dx.doi.org/10.1111/j.1751-908X.1993.tb00122.x
Grant, J.A. (1986). The isocon diagram - a simple solution of Gresens' equation for metasomatic alteration. Economic Geology. 81: 1976-1982. http://dx.doi.org/10.2113/gsecongeo.81.8.1976
Gresens, R.L. (1967). Composition-volume relationships of metasomatism. Chemical Geology, 2: 47-65. http://dx.doi.org/10.1016/0009-2541(67)90004-6
Hadj Zobir, S.; Laouar, R. & Oberhänsli, R. (2007). Les métabasites de Sidi Mohamed (Edough, NE Algérien): Caractéristiques pétrographiques, minéralogiques et géochimiques. Bulletin Du Service Géologique National, 18(1): 25-41.
Hadj Zobir, S. (2008). Caractérisation du protolithe des diatexites du massif de l'Edough (Annaba, NE Algérien). Colloque International “Terre et Eau II”, Annaba, Algérie.
Hammor, D. & Lancelot, J. (1998). Métamorphisme miocène de granites panafricains dans le Massif de l'Edough (Nord-Est de l'Algérie). Comptes Rendus de l'Académie des Sciences, Paris, série II, 327: 391-396.
Harnois, L. (1988). The CIW index: a new chemical index of weathering. Sedimentary Geology, 55: 319-322. http://dx.doi.org/10.1016/0037-0738(88)90137-6
Hilly, J. (1962). Etude géologique du Massif de l'Edough et du Cap de Fer (Est Constantinois). Publications du Service de la Carte Géologique de l'Algérie (nouvelle série) 19, 408.
McLennan, S.M.; Taylor, S.R. & Kroner, A. (1983b). Geochemical evolution of Archean shales from South Africa 1. The Swaziland and Pongola Supergroups. Precambrian Research, 22: 93-124. http://dx.doi.org/10.1016/0301-9268(83)90060-8
Middelburg, J.J.; Van Der Weijden, C.H. & Woittiez, J.R.W. (1988). Chemical Processes affecting the mobility of major, minor and trace elements during weathering of granitic rocks. Chemical Geology, 68: 253-273. http://dx.doi.org/10.1016/0009-2541(88)90025-3
Millot, G. (1964). Géologie des argiles. Masson et Cie, éd., Paris, 499 pp.
Nesbitt, H.W. (1979). Mobility and fractionation of rare earth elements during weathering of granodiorite, Nature, 279: 206-210. http://dx.doi.org/10.1038/279206a0
Nesbitt, H.W. & Young, G.M. (1982). Early Proterozoic climate and plate motions inferred from major element chemistry of lutites. Nature, 299: 715-717. http://dx.doi.org/10.1038/299715a0
Nesbitt, H.W. & Young, G.M. (1984). Prediction of some weathering trends of plutonique and volcanic rocks based on thermodynamic and kinetic consideration. Geochimica et Cosmochimca Acta, 48: 1523-1534. http://dx.doi.org/10.1016/0016-7037(84)90408-3
Oularbi, A. & Zeghiche, A. (2009). Sensibilité à l'érosion du massif cristallophillien de l'Edough (Nord-Est Algérien). Synthèse, 20: 58-72.
Pédro, G. (1966). Essai sur la caractérisation géochimique des différents processus zonaux résultant de l'altération des roches superficielles (cycle aluminosilicique). Comptes Rendus de l'Académie des Sciences Paris, 262: 1828-1831.
Piché, M. (2000). Quantification de l'altération hydrothermale des roches du camp minier de Joutel à partir des analyses des éléments majeurs. Ministère des Ressources naturelles du Québec, MB-2000-06.
Piché, M. (2001). Atelier de géochimie - Une introduction à l'utilisation des minéraux normatifs pour quantifier l'altération hydrothermale associée aux gisements de SMV et aurifères. Association des Prospecteurs du Québec, 27e Congrès annuel, 11-13 septembre 2001, Val-d'Or, Québec. Cours intensif, 30 pp.
Plessen, H.G. (1997). Analytik und Geochemie der Platingruppenelemente in magmatischen Gesteinen. Scientific Technical Report STR97/11, Geoforschungszentrum, Potsdam, 135 pp.
Potdevin, J.L. & Caron, J.M. (1986). Transferts de matière et déformation synmétamorphique pli. I:Structures et bilans de matière. Bulletin de Mineralogie. 109(4): 395-410.
Potdevin, J.L. & Marquer, D. (1987). Méthodes de quantification des transferts de matière fluides dans les roches métamorphiques déformées. Geodinamica Acta 1(3): 193-206.
Sun, S. & McDonough, W.F. (1989). Chemical and isotopic systematics of oceanic basalts; implications for mantle composition and processes. In: Magmatism in the Ocean Basins. (Saunders, A.D. & Norry, M.J., Eds.). Geological Society of London, London, United Kingdom, 313-345.
Tardy, Y. (1969). Géochimie des altérations. Étude des arènes et des eaux de quelques massifs cristallins d'Europe et d'Afrique. Thèse de Doctorat d'État, Université Strasbourg, Mémoires du Service de la Carte géologique. Alsace-Lorraine, n° 31, 199 pp.
Wronkiewicz, D.J. & Condie, K.C. (1987). Geochemistry of Archean shales from the Witwatersrand Supergroup, South Africa: source-area weathering and provenance. Geochimica et Cosmochimca Acta, 51: 2401-2416. http://dx.doi.org/10.1016/0016-7037(87)90293-6
Zuleger, E. & Erzinger, J. (1988). Determination of the REE and Y in silicate materials with ICP-AES. Analytical Chemistry, 332(2): 140-143. http://dx.doi.org/10.1007/BF00470631
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