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Characteristics and origin of sepiolite (Meerschaum) from Central Somalia

Published online by Cambridge University Press:  09 July 2018

A. Singer ,
K. Stahr  and
M. Zarei
A. Singer
Affiliation:
Seagram Center for Soil and Water Sciences, The Hebrew University of Jerusalem, PO Box 12, Rehovot 76100, Israel
K. Stahr
Affiliation:
Seagram Center for Soil and Water Sciences, The Hebrew University of Jerusalem, PO Box 12, Rehovot 76100, Israel
M. Zarei
Affiliation:
Institut für Bodenkunde u. Standortslehre, Universitat Hohenheim, D-70599 Stuttgart, Germany
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Abstract

Nearly pure sepiolite clay crops out in a playa-like depression near El Bur, Central Plateau region of Somalia. The deposit is associated with the Lower to Mid-Eocene Taleh Formation that includes, besides limestone, dolomite and gypsiferous marls, extensive anhydrite and various evaporites, primarily gypsum. The material was examined by XRD, DTA, IR and EM. The XRD and DTA analyses indicated that from 40 cm down to a depth of 300 cm, the material consists of well crystallized sepiolite, accompanied in some layers by minor calcite and traces of quartz and halite. The chemical composition, determined by XRF, indicated a low-Fe mineral, with the formula: (Si11.888Al0.l12)(Mg7.313Al0.154Fe0.084)O30(OH2)4(OH2)4.x8H2O.

The fibres, arranged in the form of interwoven mats, are straight and have lengths varying between 2-6 µm and widths of 20-40 nm. Commonly, they are aggregated into units of two parallel-lying fibres, with a random orientation against each other, creating a dense network of pores. The high viscosity and external surface area (306-346 m2g-1) of the material, compared to those of the Spanish Vallecas sepiolite, suggest the high industrial suitability of this clay. The extent of the deposit is not known. Lithology and geomorphology indicate a lacustrine, closed basin evaporative environment of formation for this deposit. In contrast to the palaeolacustrine environments of formation of Spanish and Turkish sepiolite deposits, the E1 Bur sepiolite apparently is more recent.

Type
Research Article
Information
Clay Minerals , Volume 33 , Issue 2 , June 1998 , pp. 349 - 362
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1998

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References

Ahrens, T.P. (1951) A Reconnaissance Groundwater Survey of Somalia, East Africa. Comitato interministriale per la reciostruzione, Roma.Google Scholar
Alaily, F., Lassonczyk, B., Huth, A. & Genisor, B. (1990) Genesis of soils in the arid part of north-east Somalia. Berline Geowiss. Abh. (A) 120(2), 695-704. Berlin.Google Scholar
Bachman, G.O. & Machette, M.N. (1977) Calcic soils and calcretes in the southwestern United States. U.S. Geol. Survey Open-File Rept. 77-794, 163 p.Google Scholar
Bailey, S. (1980) Structures of clay minerals. Pp. 1-123 in: Crystal Structures of Clay Minerals and their Xray Identification (Brindley, G. & Brown, G., editors). Mineralogical Society, London.Google Scholar
Boaler, S.B. & Hodge, C.A. (1964) Observations on vegetation areas in the northern region, Somali Republic. J. Ecol., 52, 511–544.Google Scholar
Caillere, S., Henin, S. & Rautureau, M. (1983) Mineralogie des Argiles, Vol. 2, Masson, Paris.Google Scholar
Doval, M., Calvo, J.P., Brell, J.M. & Jones, B.F. (1986) Clay mineralogy of the Madrid basin: Comparison with other lacustrine closed basins. Pp. 188–189 in: Geochemistry of the Earth Surface and Processes of Mineral Formation (abst.) (Rodriguez-Climente, R. & Tardy, Y., editors).Google Scholar
Drechsel, P. (1991) Bodengesellschaften Centralsomalias: IJkologie und Genese. Bayreuther Bodenkundliche Berichte. Band 19, Bayreuth.Google Scholar
Ece, O.I. & Coban, F. (1994) Geology, occurrence and genesis of Eskisehir sepiolites, Turkey. Clays Clay Miner. 42, 81–92.Google Scholar
Federal Statistical Office (1991) Statistics of Foreign Countries, Somalia. J. Be. Metzler and C. E. Poeschel Publ. Wiesbaden, Germany.Google Scholar
Gahin, E. (1987) Industrial applications of sepiolite from Vallecas-Vicalvaro, Spain: A review. Proc. Int. Clay Conf. Denver, 400-404.Google Scholar
Gahin, E. & Castillo, A. (1984) Sepiolite-palygorskite in Spanish Tertiary Basins: Genetical patterns in continental environments. Pp. 87 – 124 in: Palygorskite-Sepiolite, Occurrences, Genesis and Uses (Singer, A. & Galan, E., editors). Dev. Sedimentol. 37. Elsevier, Amsterdam.Google Scholar
Garrels, R.H. & MacKenzie, F.T. (1967) Origin of the chemical composition of some springs and lakes. Pp. 222-242 in: Equilibrium Concepts in Natural Water Systems (Stumm, W., editor). American Chemical Society, Advances in Chemistry, v. 67.Google Scholar
Gehring, A.V., Keller, P., Frey, B. & Luster, J. (1995) The occurrence of spherical morphology as evidence for changing conditions during the genesis of a sepiolite deposit. Clay Miner. 30, 83–86. Grossher, D. (1978) Somalia Hantiwadaag. Kubler, Heidelberg.Google Scholar
Hay, R.L. & Stoessell, R.K. (1984) Sepiolite in the Amboseli Basin of Kenya: A new interpretation. Pp. 125–136 in: Palygorskite-Sepiolite, Occurrences, Genesis and Uses (Singer, A. & Galan, E., editors). Dev. Sedimentol. 37. Elsevier, Amsterdam.Google Scholar
Hay, R.L, Pexton, R.E., Teague, T. & Kyser, K. (1986) Spring-related carbonate rocks, Mg clays and associated minerals in Pliocene deposits of the Amargosa desert, Nevada and California. Geol. Soc. Am. Bull., 97, 1488–1503.Google Scholar
Hay, R.L, Hughes, R.E., Kyser, T.K., Glass, H.D. & Lin, J. (1995) Magnesium-rich clays of the Meerschaum mines in the Amboseli Basin, Tanzania and Kenya. Clays Clay Miner. 43, 455–466.Google Scholar
Hendricks, F., Behrens H,, Busch, W., Bussmann, M., Gebhardt, H., Gorier, K., Reuleke, D., Strouhat, A. & Uhmann A, (1993) Detrital palygorskite in lacustrine and lagoonal clay-mineral associations of Late Tertiary age from Morocco and Somalia. Zbl. Geol. Palaont. Teil 1, 1992 H. 5, 415–436.Google Scholar
Jones, B.F. & Gahin, E. (1988) Sepiolite and palygorskite. Pp. 631-674 in: Hydrous Phyllosilicates (Bailey, S.W., editor). Reviews in Mineralogy, Vol. 19, Mineralogical Society of America, Washington, D.C.Google Scholar
Kautz, K. & Porada, H. (1976) Sepiolite formation in a pan of the Kalahari. N. Jb. Mineral Mh. 545-559.Google Scholar
Leguey, S., Martin-Rubi, J., Casas, J., Marta, J., Cuevas, J., Alvarez, A. & Medina, J. (1995) Diagenetic evolution and mineral fabric in sepiolitic materials from the Vicalvaro deposit (Madrid Basin). Proc. lOth Int. Clay Conf. Adelaide, 383-392.Google Scholar
Millot, G. (1964) Geologie des Argiles, Masson and Cie, Paris, 510 pp.Google Scholar
Osman, A.S., Farag, H.A. & Abdi, M.S. (1985) Geology of Somalia. Ministry of Minerals and Water Res., Mogadishu.Google Scholar
Peterson, E. & Swaffield, R. (1987) Thermal Analysis. Pp. 99–132 in: A Handbook of Determinative Methods in Clay Mineralogy (Wilson, M.J., editor), Blackie, Glasgow & London.Google Scholar
Singer, A., Kirsten, W.F.A. & Bohmann, C. (1992) Occurrence of sepiolite in the northern Transvaal, South Africa. S. Afr. J. Geol. 95, 165–170.Google Scholar
Stahr, K., Zarei, M. & Jahn, R. (1990) Autigene Sepiolithbildung im Gebiet yon El Bur (Zentral- Somalia). Mitt. Dt. Bodenkund. Ges. 62, 147–150.Google Scholar
Watson, R.M., Tippett, C.F., Beckett, J.J. & Scholes, V. (1982) Resource Management and Research. Somali Democratic Republic, Central Rangelands Survey, Vol. 1 Parts 1 and 3, London (unpublished, copies in the Library of the NRA in Mogadishu).Google Scholar
Webster, D.M. & Jones, B.F. (1994) Paleoenvironmental implications of lacustrine clay minerals from the Double Lakes formation, southern High Plains, Texas. Pp. 159-172 in: Sedimentology and Geochemistry of Modern and Ancient Saline Lakes. SEPM Special Publ. No. 50.Google Scholar
Yeniyol, M. (1995) Meerschaum sepiolite and palygorskite ocurrence in Central Anatolia, Turkey. Proc. 10th Int. Clay Conf. Adelaide, 378-382.Google Scholar