Publications

Found 19 results

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2017
Martelat J-E, Paquette J-L, Bosse V, Giuliani G, Monié P, Omito E, Simonet C, Ohnenstetter D, Daniel Ichang'i, Nyamai C, Wamunyu A. "Chronological Constraints On Tsavorite Mineralizations and Related Metamorphic Episodes In Southeast Kenya." The Canadian Mineralogist. 2017;55(5):845-865. AbstractFull text link

Tsavorite is exclusively hosted in the Neoproterozoic Metamorphic Mozambique Belt (NMMB). The gemstone mines, widespread between Kalalani (Tanzania) and Mgama Ridge (Kenya), define a continuous corridor over a hundred kilometers in length. The tsavorite is hosted by a metasedimentary sequence defined as the Kurase tsavorite-bearing metasediments (Kurase-TB metasediments) that also hosts rubies. These metasediments underwent amphibolite-facies metamorphism and are surrounded by granulitic gneisses that are also of sedimentary origin (the Kurase high-temperature gneisses). All these rocks lie below the Kasigau Group, a unit dominated by granulite-facies metamagmatic rocks.

To constrain the timing of events that led to this peculiar occurrence of tsavorite, we have performed geochronological analyses of thin sections and of separated grains of zircon, monazite, and rutile using LA-ICP-MS and ID-TIMS, as well as 40Ar/39Ar of muscovite and phlogopite from various lithologies. The results show that the different terranes were metamorphosed synchronously between 620–580 Ma but under different P-T strain conditions. The Kurase-HT gneisses and the rocks from the Kasigau Group are highly strained and underwent granulite-facies metamorphism with abundant partial melting and emplacement of felsic melts between 620 and 600 Ma. Textural observations also underlined a late regional water flux controlling the occurrence of V-free muscovite and monazite mineralizations at 585 Ma. The latter event can be related to the activity of the Galana shear zone, in the east. The Kurase-TB metasediments escaped strain and partial melting. They record amphibolite-facies conditions with static heating, since initial sedimentary structures were locally preserved. The age of the tsavorite mineralization was inferred at 600 Ma from metamorphic zircon rims and monazite from the closest host-rocks, sampled in the mines. Hence, tsavorite crystallization occurred statically at the end of the metamorphic event, probably when the temperature and the amount of volatiles were at maximum levels.

Conversely, the ruby formed by local metasomatism of felsic dikes and isolated ultramafic bodies. The rubies are older and zircons and monazites from a ruby-bearing felsic dike (plumasite) were dated at 615 Ma. Finally, data from rutile and micas indicate a global cooling below 430 °C of the whole region between 510 and 500 Ma.

2002
W DRICHANGIDANIEL. "A voluminous occurrence of high-K dacites and related granites of Archaean age in Kenya.". In: African Journal of Science and Technology, Science and Engineering Series, Vol. 3, No. 2, 34-51. Philosophical Issues Invoked by Shona People; 2002. Abstract
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1999
W DRICHANGIDANIEL. "The environmental impact of landslides on the population living on the eastern footslopes of the Aberdare ranges in Kenya. A case studyof Maringa Village Landslide. Journal of Environmental Geology , 38, No. 3, 259-264.". In: African Journal of Science and Technology, Science and Engineering Series, Vol. 3, No. 2, 34-51. Philosophical Issues Invoked by Shona People; 1999. Abstract
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W DRICHANGIDANIEL. "Geological Setting of the Bukura-Mbesa Kavirondian turbidite-hosted massive sulphide deposit in western Kenya. Journal of African Earth Sciences, Special Abstracts Vol., 28, 30-31.". In: African Journal of Science and Technology, Science and Engineering Series, Vol. 3, No. 2, 34-51. Philosophical Issues Invoked by Shona People; 1999. Abstract
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W DRICHANGIDANIEL. "The Geological Society of Kenya Stratigraphy and Nomenclature Committee: Proposed procedure and practice. Geological Society of Kenya 8th Conference Abstracts Volume, 21-22.". In: African Journal of Science and Technology, Science and Engineering Series, Vol. 3, No. 2, 34-51. Philosophical Issues Invoked by Shona People; 1999. Abstract
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W DRICHANGIDANIEL. "Ichang.". In: Geological Society of Kenya 8th Conference Abstracts Volume, 21- 22. Philosophical Issues Invoked by Shona People; 1999. Abstract
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W DRICHANGIDANIEL. "Ichang'i, D.W., Nyambok, I.O. and Gaciri, S.J. Geological Setting of the Bukura-Mbesa Kavirondian turbidite-hosted massive sulphide deposit in western Kenya.". In: Journal of African Earth Sciences, Special Abstracts Vol., 28, 30-31. Philosophical Issues Invoked by Shona People; 1999. Abstract
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W DRICHANGIDANIEL. "Ngecu, W.M. and Ichang'i, D.W. The environmental impact of landslides on the population living on the eastern footslopes of the Aberdare ranges in Kenya.". In: A case study of Maringa Village Landslide. Journal of Environmental Geology , 38, No. 3, 259-264. Philosophical Issues Invoked by Shona People; 1999. Abstract
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W DRICHANGIDANIEL. "Opiyo-Akech, N., Tarney, J. and Ichang.". In: Geological Society of South Africa Annual Meeting 24th. June, 1999. Abstract. Philosophical Issues Invoked by Shona People; 1999. Abstract
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1997
W DRICHANGIDANIEL. "Ichang.". In: Report and recommendations of the First Kenya Gemstone and Dealers Workshop. Geological Society of Kenya Bulletin, 1, 6 pp. Philosophical Issues Invoked by Shona People; 1997. Abstract
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1996
W DRICHANGIDANIEL. "Geological Society of Africa 10 th International Conference GSA '95 Proceedings Volume. Edited by Nyambok, I.O. and Ichang.". In: Report and recommendations of the First Kenya Gemstone and Dealers Workshop. Geological Society of Kenya Bulletin, 1, 6 pp. Philosophical Issues Invoked by Shona People; 1996. Abstract
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1995
W DRICHANGIDANIEL. "Nyamai, C.M., Itagaki, K. and Ichang'i, D.W. Phase relations in the Cu 2S-S-FeS-ZnS and Cu2S-PbS-ZnS Ternary - Systems at 1473K: Extraction of zinc from sulfide ore using liquid copper as a reagent. In:.". In: Geological Society of Africa 10 th International Conference GSA '95 Proceedings Volume (Edited by I.O. Nyambok and D.W. Ichang. Philosophical Issues Invoked by Shona People; 1995. Abstract
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1994
W DRICHANGIDANIEL. "Mathu, E.M., Ichang.". In: International Geological Correlation Programme ( I.G.C.P.) Project 348. Proceedings of the International Geological Field Conference held in the Mazambique Orogenic Belt in East Africa. Organised by the University of Dar-es-Salaam, University of Na. Philosophical Issues Invoked by Shona People; 1994. Abstract
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1993
W DRICHANGIDANIEL. "Ichang'i, D.W. Lithostratigraphic setting of the mineralisation in the Migori segment of the Nyanza greenstone belt, Kenya. In:.". In: Geology for Sustainable Development (Edited by N. Opiyo-Akech), Proceedings, Geological Society of Kenya 5th. Conference, 78-84. Philosophical Issues Invoked by Shona People; 1993. Abstract
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W DRICHANGIDANIEL. "Ichang'i, D.W. Proposal for the formation of a working group to revise the stratigraphic nomenclature applied to the Archaean terrane of western Kenya. In:.". In: Geology for Sustainable Development (Edited by N. Opiyo - Akech), Proceedings, Geological Society of Kenya 5th. Conference, 122-129. Philosophical Issues Invoked by Shona People; 1993. Abstract
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1992
W DRICHANGIDANIEL. "Ichang'i, D.W. A lithostratigraphic framework for the Migori segment of the Archean Nyanza greenstone belt, Tanzanian Craton, East Africa. In: Regional.". In: Trends in African Geology (Edited by J.W. Peters, G.O. Kesse and P.C. Acquah), Proceedings, Geological Society of Africa 9th. Int. Conference, Accra, Ghana, 200-215. Philosophical Issues Invoked by Shona People; 1992. Abstract
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1991
W DRICHANGIDANIEL. "Ichang'i, D.W. and MacLean , W.H. The Archean Volcanic facies in the Migori segment, Nyanza greenstone belt, Kenya: stratigraphy, geochemistry and mineralisation.". In: Journal of African Earth Sciences, 413, 277-290. Philosophical Issues Invoked by Shona People; 1991. Abstract
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1990
W DRICHANGIDANIEL. "Ichang.". In: Geology, Geochemistry and Economic Mineral Potential. Ph.D. Thesis, McGill University, Montreal, 147 pp. Philosophical Issues Invoked by Shona People; 1990. Abstract
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1983
W DRICHANGIDANIEL. "Ichang.". In: Geology, Geochemistry and Economic Mineral Potential. Ph.D. Thesis, McGill University, Montreal, 147 pp. Philosophical Issues Invoked by Shona People; 1983. Abstract
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