 | | Journal (article/letter/editorial) | | Pegmatitic Rocks and Minerals in the Kenticha Belt, Southern Ethiopia: Implication to Geological Setting...Ababa University, P. 0.Box 1176, Addis Ababa, Ethiopia (Manuscript received April 18, 2000; accepted...pegmatites, alaskites) and minerals from the Kenticha pegmatite field. The data shed light on the evolution...granite-pegmatites and associated mineralization in the Kenticha belt. The complex mineralization of commercial...signatures of the suite of felsic rocks of the Kenticha belt are predominantly similar to those generated |  | Mogessie, A., Krenn, K., Schaflechner, J., Koch, U., Egger, T., Goritchnig, B., Kosednar, B., Pichler, H., Ofner, L., Bauernfeind, D., Tadesse, S., Demessie, M. (2002) A geological excursion to the Mesozoic sediments of the Abay Basin (Blue Nile), recent volcanics of the Ethiopian main rift and basement rocks of the Adola Rea, Ethiopia. Mitteilungen der Ćsterreichischen Mineralogischen Gesellschaft, 147. | Journal (article/letter/editorial) | | MAIN RIFT AND BASEMENT ROCKS OF THE ADOLA REA, ETHIOPIA by A. Mogessie, K. Krenn, J. Schaļ¬echner, U...Addis Ababa University, Ethiopia 2Ethiopian Institute of Geological Surveys Ethiopia 43 44 1. GENERAL...INTRODUCTION The ļ¬eld excursion to Ethiopia took place from April 5 to 22, 2001. Ethiopia has a varied geology and...making up the Ethiopian plateau; ii) the Main Ethiopia Rift containing a number of lakes and geothermal...ļ¬elds and iii) the Adola gold belt including the Kenticha tantalum-bearing pegmatites (Fig. 1). Nine earth |  | KĆ¼ster, Dirk, Romer, Rolf L., Tolessa, Dandena, Zerihun, Desta, Bheemalingeswara, K., Melcher, Frank, OberthĆ¼r, Thomas (2009) The Kenticha rare-element pegmatite, Ethiopia: internal differentiation, UāPb age and Ta mineralization. Mineralium Deposita, 44 (7) 723-750 doi:10.1007/s00126-009-0240-8 | Journal (article/letter/editorial) | | 1007/s00126-009-0240-8 ARTICLE The Kenticha rare-element pegmatite, Ethiopia: internal differentiation, UāPb...Springer-Verlag 2009 Abstract The Kenticha rare-element pegmatite, a globally important tantalite source...source in the Neoproterozoic Adola Belt of southern Ethiopia, is a highly fractionated, huge (2,000 m long...rareelement pegmatite class and belongs to the lithiumācesiumā tantalum petrogenetic family. The Kenticha pegmatite...an internal geochemical differentiation of the pegmatite sheet proceeding from the lower zone (K/Rb ~36 |  | | Journal (article/letter/editorial) | | the PanAfrican Rocks of the Adola Area, Southern Ethiopia Solomon Tadesse Depnutnienf of Geology and Geophysics...Adola volcano-sedimentary sequence, in southern Ethiopia. Two major mineralized belts can be recognized:...recognized: the Megado ('Gold Belt') and the Kenticha Belts. The Kenticha Belt is also known for its rare metal...exploration programme Key words: Adola, gold, Kenticha, Lega Dembi, Pan-African, rare metal, Sakaro....placers, have been reported from various regions in Ethiopia. However, the Adola Goldfield is the only one |  | | Journal (article/letter/editorial) | | (mainly Rwanda and the DR Congo), around the Kenticha mine (Ethiopia) and in the Alto Ligonha Province (Mozambique)...(Mozambique), the Arabian-Nubian Shield (Egypt, Ethiopia) and the Tantalite Valley pegmatites (southern...1992; ÄernĆ½ et al., 2005). The provenance of pegmatite magmas remains poorly understood. Based on a study...afļ¬liation and rare-element signature of the granite-pegmatite systemsā. Peraluminous granites and associated...Democratic Republic of the Congo (DRC), Mozambique, Ethiopia, Nigeria and Burundi (Table 1). Notably, the majority |  | | Report (issue) | | ............................................M24 Mine Waste Characteristics ........................................................................M27 Mine Closure ..........................................regional lithium-cesium-tantalum rare-metalbearing pegmatite zoning above a parental granite.................zoned lithium-cesium-tantalum rare-metal-bearing pegmatite..............................................................M21 M13. Bar charts showing global mine production of niobium and tantalum, from 2000 to |  | | Journal (article/letter/editorial) | | PRECAMBRIAN PODIFORM CHROMITITES FROM KENTICHA HILL, SOUTHERN ETHIOPIA F. F. BONAVIA,* Universitd Pierreet...tinizedperidotitesbelongingto a metamorphic belt Kenticha Hill Chromitites that isLate Proterozoicin age...mineralogy,minDetailed mapping (Bogliotti, 1989) at Kenticha eral chemistry,and platinum-groupelement (PGE)...Precambrianrocks of southern On the eastern flank of Kenticha Hill, at an elevaEthiopiaare a three-foldsuccession;...rite),PGM(studyinprogress), Fe oxides(mainly magnetite,ilmenite,and lessfrequentlyhematite), andFe-Ni |  | | Journal (article/letter/editorial) | | Structure of Precambrian Rocks in the Adola Goldfield (Ethiopia) based on Two Generations of Interference Pattern...Institute of Geological Survey of Ethiopia, P.O. Box 5580, Addis Ababa (Ethiopia) (Received December 71 1987;...structure of Precambrian rocks in the Adola Goldfield (Ethiopia) based on two generations of interference pattern...mapped in Precambrian rocks of the Adola Goldfield (Ethiopia). The F2 phase folded pre-existing planes (D1)...been active in the !ate Precambrian of southern Ethiopia. Introduction It is now generally accepted that |  | Melcher, Frank, Graupner, Torsten, GƤbler, Hans-Eike, Sitnikova, Maria, Henjes-Kunst, Friedhelm, OberthĆ¼r, Thomas, Gerdes, Axel, Dewaele, Stijn (2015) Tantalumā(niobiumātin) mineralisation in African pegmatites and rare metal granites: Constraints from TaāNb oxide mineralogy, geochemistry and UāPb geochronology. Ore Geology Reviews, 64. 667-719 doi:10.1016/j.oregeorev.2013.09.003 | Journal (article/letter/editorial) | | Schist Belt (western Zimbabwe) 4.3.3. Orange River Pegmatite Belt (Namibia, South Africa) AC 4.3.3.1. Radiometric...data 4.4.1.2. Mineralogy 4.4.2. Pegmatites of Ethiopia and Somalia 4.4.2.1. Radiometric data 4.4.2.2...3.2. Kamativi Schist Belt 5.3.3. Orange River Pegmatite Belt 5.4. Late Neoproterozoic to early Paleozoic...the Eastern Desert (Egypt) 5.4.2. Pegmatites of Ethiopia and Somalia 5.4.3. Alto-Ligonha Province (Mozambique)...presented for 13 rare-element granite NU and pegmatite districts in Africa, covering Archean, Paleoproterozoic |  | AHMED, A, ARAI, S, ABDELAZIZ, Y, RAHIMI, A (2005) Spinel composition as a petrogenetic indicator of the mantle section in the Neoproterozoic Bou Azzer ophiolite, Anti-Atlas, Morocco. Precambrian Research, 138 (3) 225-234 doi:10.1016/j.precamres.2005.05.004 | Journal (article/letter/editorial) | | composed mainly of chlorite, antigorite, and magnetite. Primary silicate inclusions have been altered...shape and has intact core and altered Cr-rich magnetite rim with a sharp optical boundary (Fig. 4F). ...(Table 1). The altered rim of spinel is Cr-bearing magnetite (Fig. 5). Chromian spinel also shows a uniform...Fig. 5). Altered spinel rim is also Cr-bearing magnetite in dunite (Fig. 5). Chromian spinel occasionally...Anti-Atlas, Morocco. (A) Bastite pseudomorph showing magnetite striations after the pre-existing cleavage of |  | | Report (issue) | | crisp despite partial dehydration) from the Margabal mine, Entraygues, Aveyron Department, France. 1 ļ„==...=======ļ„ Torbernite, 5.3 cm, from the Margabal mine, Entraygues, Aveyron, France. Trinity Minerals specimen...specimen and photo. This small uranium mine, in a small deposit discovered during a survey by the French...locality began in June 1997 when, somewhere in the old mine, about 1,000 fine specimens were recovered, with...$250. Vanadinite, 2.3 cm, from the North Geronimo mine, La Paz County, Arizona. Keyās Minerals specimen |  | Yan, Qing-He, Qiu, Zeng-Wang, Wang, He, Wang, Min, Wei, Xiao-Peng, Li, Pei, Zhang, Rong-Qing, Li, Cong-Ying, Liu, Jian-ping (2018) Age of the Dahongliutan rare metal pegmatite deposit, West Kunlun, Xinjiang (NW China): Constraints from LAāICPāMS UāPb dating of columbite-(Fe) and cassiterite. Ore Geology Reviews, 100. 561-573 doi:10.1016/j.oregeorev.2016.11.010 | Journal (article/letter/editorial) | | com/locate/oregeo Age of the Dahongliutan rare metal pegmatite deposit, West Kunlun, Xinjiang (NW China): Constraints...online xxxx Keywords: Dahongliutan rare metal pegmatite deposit Kunlun orogenic belt Columbite-(Fe) and...Dahongliutan is a medium-size LiāBeāTaāNb rare metal pegmatite deposit in the Tianshuihai terrane, West Kunlun...represents the emplacement age of the pegmatite dikes. The ore-hosting pegmatite dikes are intimately time-space...reserves in China, implying that the Dahongliutan pegmatite deposit may also have favorable oreforming conditions |  | Aurisicchio, Carlo, Conte, Aida M., Medeghini, Laura, Ottolini, Luisa, De Vito, Caterina (2018) Major and trace element geochemistry of emerald from several deposits: Implications for genetic models and classification schemes. Ore Geology Reviews, 94. 351-366 doi:10.1016/j.oregeorev.2018.02.001 | Journal (article/letter/editorial) | | distinguishes the emerald deposits related to granite-pegmatite intrusion from those controlled by tectonic structures...the phlogopitebearing contact zones, between pegmatite and surrounding Cr-bearing mafic-ultramafic rocks...pre-Karoo age. The genetic model for emerald-bearing pegmatite (Maria III and Niane) involves the intrusion of...with quartz, feldspar, and topaz occur in small pegmatite pockets (up to 8 cm in size) at the contact granite-country...Crrich (3000 to 4000 ppm) talc-chloriteĀ±actinoliteĀ±magnetite metabasites of the metamorphosed komatiites of |  | | Journal (article/letter/editorial) | | Geological Surveys, P.O. Box 5580, Addis Ababa, Ethiopia. Band.67, Heft 2, 1978, SeRe 531--546 531 Aufs~itze...or 8 years, mostly b y the Geological Survey of Ethiopia. Important contributions to the basement geology...Omo River Project (1973, 1976). The position of Ethiopia is u n i q u e in that within its territory the...(the Boye Series), and possibly occurs in western Ethiopia. In Sidamo and Hararge it is represented by psammitic...calc-silicates and amphibole schists. In western Ethiopia these rocks are intercalated with amphibole schists |  | | Journal (article/letter/editorial) | | % from tin slag refining and 10 % from secondary mine concentrates. Due to rapid industrialisation and...Canada account for about 92 and 7 % of Nb world mine production, respectively. Since the bulk of the...maintenance. Ta production at the massive Greenbushes pegmatite (Australia) has stopped, though Li production...start-up time for new operations. The Kenticha mine (Ethiopia) is a past producer that may re-enter production...studies on new developments) are required in any mine as price levels vary for each deposit and are dependent |  | | Journal (article/letter/editorial) | | (darker) set up in ferritchromite and Cr-rich magnetite. ReĀÆected light. C Subhedral chrome spinel grain...D Zonation of chrome spinel of ferritchromite-magnetite (brighter) developed through the cracks inward...orthopyroxene crystals. They have bastite textures with magnetite striations that may Ā®ll the cleavage of the original...completely altered to ferritchromite, Cr-rich magnetite or magnetite in some cases. Chrome spinel grains are...primary intact parts within ferritchromite and magnetite (Fig. 2B). Dunite Dunite is common as envelopes |  | | Journal (article/letter/editorial) | | gold mineralization in the Okote area, southern Ethiopia DEBELE J. D EKSISSA1,2 and C HRISTIAN KOEBERL2*...KOEBERL2* 1 2 P.O. Box 28503, Addis Ababa, Ethiopia Department of Geological Sciences, University of Vienna...mineralization of the Okote area is located in southern Ethiopia. Three NS striking ductile shear zones, with different...zones indicate that epidote, ferroamphiboles, and magnetite were formed first, followed by chlorite, ankerite...positive Eu anomaly in the epidote-amphibole-magnetite rich transitional zone, and HREE enrichment with |  | | Book | | crystals on large, well-formed grey graphite crystals, field of view 3 cm - Philip Hitge specimen, Bruce Cairncross...runs from Madagascar through Tanzania, Kenya, Ethiopia and into the Sudan - has blessed East Africa,...countries are among the finest in the world. The region and its gems are particularly dear to my family...most renowned gemstones from East Africa, this region is also host to some of the world's finest examples...several other varieties of gemstone occur in the region and, while perhaps not as popular, these too have |  | | Journal (issue) | | Decade of Change A New Era for the Historic Coscuez Mine Esmeraldas Santa Rosa: Our Wealth is Green Rediscovery...More Exquisite Emeralds Magnificent Old Mine Emeralds 143 Mine Visit A Visit to Colombiaās āGreenā Emerald...acquiring the majority stake in the iconic Coscuez mine in Colombia. The 2015 Symposium focused on the governmentās...have also seen new discoveries of emeralds in Ethiopia and increased awareness of the green gem from...confidence in gem purchases now starts at the mine in the broader mine-to-market concept. Another major change |  | | Journal (article/letter/editorial) | | (1976) suggested late Proterozoic ages based on the field relations, whereas El Gaby et PT E al. (1988,...the adjacent metasediments for a few meters. Pegmatite pockets, partially greisenized, occur locally...thoughout the Mueilha granite pluton are zircon, magnetite that locally intergrown with ilmenite, sphene...red granites fall wholly within alkali granite field on the R1-R2 discrimination diagram (Fig. 4c). ...plot within the field SC of A1-type granites while the red granites fall within the field of A2-type granites |  | El Ghorfi, M., Melcher, F., OberthĆ¼r, T., Boukhari, A. E., Maacha, L., Maddi, A., Mhaili, M. (2008) Platinum group minerals in podiform chromitites of the Bou Azzer ophiolite, Anti Atlas, Central Morocco. Mineralogy and Petrology, 92 (1) 59-80 doi:10.1007/s00710-007-0208-2 | Journal (article/letter/editorial) | | replacement by āāferritchromiteāā, Cr-rich magnetite and=or magnetite. Note that throughout the manuscript...chromite. Sample R036921a; (C) BSE image showing magnetite (Mt) infilling cracks crosscutting chromite (Ch)...ferrit-chromite (Fch) intermediate zone and a magnetite (Mt) rim. Sample AS6921a replaced by serpentine...serpentine minerals, chlorite, talc, carbonate and magnetite. Some chromitite pods are encrusted by violet-coloured...Al Ays, Saudi Arabia (Quick, 1990), and Kenticha Hills, Ethiopia (Bonavia et al., 1993). Highly metamorphosed |  | | Journal (article/letter/editorial) | | Assessing copper fertility of intrusive rocks using field portable X-ray fluorescence (pXRF) dataāAyesha Ahmed...skarn-porphyry Cu-Au-Fe deposit, eastern Transbaikal region, Russia: Genetic implicationsāV.A. Kovalenker,...alluvial placers of the Krasnovishersky district (Ural region)ā E.A. Vasilev, I.V. Klepikov, and L.I. Lukianova...Nb- and Ta-bearing biotite from the Lizaizhai pegmatite (Guangning ore district, Guangdong, south China):...of the newly discovered late Mesozoic granite-pegmatite and associated Sn-Nb-Ta-Be mineralization in the |  | | Journal (article/letter/editorial) | | the Lega Dembi Gold Deposit, Adola Gold Field, Southern Ethiopia Solomon Tadesse Department of Geology...Addis Ababa University, PO. Box 1176, Addis Ababa, Ethiopia (Manuscript received March 12,2003; accepted January...The Lega Dembi Primary Gold Deposit in southern Ethiopia is related to the shear zone-hosted vein in the...origin related to mafic volcanism. Key words: Ethiopia, Lega Dembi, gold, volcano-sedimentary sequence...south of Addis Ababa in the Adola belt, southern Ethiopia. The deposit is located along the Lega Dembi-Aflata |  | | Journal (issue) | | INVERELL BLUE By Antoinette Rahn REGULAR COLUMNS Field Notes ........................... 6 Earth Science...winner, Marie Curie. Extracted from the Musonoi Mine, Kolwezi Dist., the Democratic Republic of the Congo...RandG_official rockngem.com 4 ROCKNGEM.COM FIELD NOTES This is the usual, but never boring, view...important. Additionally, as I mentioned in the Field Notes section of the July edition of Rock & Gem....com 877.793.6636 NEW OPAL SHIPMENT IN FROM ETHIOPIA THIS MAY BE THE BRIGHTEST PARCEL WEāVE EVER RECEIVED |  | Giuliani, Gaston, Groat, Lee A., Marshall, Dan, Fallick, Anthony E., Branquet, Yannick (2019) Emerald Deposits: A Review and Enhanced Classification. Minerals, 9 (2) 105 doi:10.3390/min9020105 | Journal (article/letter/editorial) | | type, in terms of production, is the desilicated pegmatite related type that formed via the interaction of...of previous beryllium mineralization, such as pegmatite intrusions in mafic-ultramafic rocks. Such new...ct. Insufu rough emerald extracted from the Kagem mine in 2015. Lastly, on the 2th of October, the remarkable...(āthe lion elephantā) was extracted from the same mine [3]. Other giant crystals have been discovered in...emerald crystals was discovered in the CarnaĆba mine, Brazil; the specimen weighed 341 kg with 1.7 million |
|
