| | 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 Österreichischen Mineralogischen Gesellschaft, 147. | Journal (article/letter/editorial) | MAIN RIFT AND BASEMENT ROCKS OF THE ADOLA REA, ETHIOPIA by A. Mogessie, K. Krenn, J. Schaflechner, U...Addis Ababa University, Ethiopia 2Ethiopian Institute of Geological Surveys Ethiopia 43 44 1. GENERAL...INTRODUCTION The field 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...fields and iii) the Adola gold belt including the Kenticha tantalum-bearing pegmatites (Fig. 1). Nine earth | | | 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 | | Küster, Dirk, Romer, Rolf L., Tolessa, Dandena, Zerihun, Desta, Bheemalingeswara, K., Melcher, Frank, Oberthür, Thomas (2009) The Kenticha rare-element pegmatite, Ethiopia: internal differentiation, U–Pb 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, U–Pb...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 lithium–cesium– 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 ophiolitic fold and thrust belts of southern Ethiopia: constraints on the tectonic regime during the...Neoproterozoic ophiolitic belts in southern Ethiopia—Megado, Kenticha, Moyale-El Kur and Bulbul. The mafic rocks...geochemistry, similar to that reported from the Kenticha Belt. Several samples from the Geleba area and...tectonic evolution of the Neoproterozoic of southern Ethiopia. © 2002 Elsevier Science B.V. All rights reserved...157–183 1. Introduction The Precambrian of southern Ethiopia, which consists of high-grade ortho- and para-gneisses | | 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...contact between granite and talc schists/talc–actinolite schists (Fersmann, 1929) into pegmatitic pockets...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 | | | Journal (article/letter/editorial) | geology of the Lega Dembi gold deposit, southern Ethiopia: implications for Pan-African gold exploration...Dembi deposit is the largest gold producer in Ethiopia. It is situated in late-Precambrian metamorphosed...lateProterozoic Adola granite-greenstone terrane in southern Ethiopia. The lode-gold mineralization occurs in a N-S...contact. Hydrothermal wall-rock alteration includes actinolite/tremolite-biotitecalcite-sericite and chlorite-calcite-epidote...conditions of mineralization are constrained by the actinolite-biotite alteration assemblage and by arsenopyrite | | | Journal (article/letter/editorial) | southern Ethiopia Lulu Tsige a , Mohamed G. Abdelsalam b,∗ a Geological Survey of Ethiopia, Department...Regional Mapping, Addis Ababa, P.O. Box 2302, Ethiopia b The University of Texas at Dallas, Department...metamorphic data from the Bulbul Belt in southern Ethiopia indicating that the latest phase of the Neoproterozoic...migmatitic layering that is not evident elsewhere in the region. This older planar fabric is discordantly overprinted...the Neoproterozoic N-trending belts in southern Ethiopia were roots of northward expulsion of the Arabian-Nubian | | | 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 (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...Keywords: gold mineralization, fluid inclusion, Ethiopia, tourmaline, rare earth element deposit and ubiquitous...The hydrothermal wall rock alteration includes actinolite/tremolite-biotite-calcite-sericite-tourmaline | | | 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) | 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 Colombia’s “Green” Emerald...acquiring the majority stake in the iconic Coscuez mine in Colombia. The 2015 Symposium focused on the government’s...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 | | “Beraki, W. H., Bonavia, F. F., Getachew, T., Schmerold, R., Tarekegn, T. (1989) The Adola Fold and Thrust Belt, southern Ethiopia: a re-examination with implications for Pan-African evolution. Geological Magazine, 126 (6) 647-657 doi:10.1017/s0016756800006944 | Journal (article/letter/editorial) | 647 The Adola Fold and Thrust Belt, southern Ethiopia: a re-examination with implications for Pan-African...Project, UNDP ETH 86/034, P.O.Box 5580, Addis Ababa, Ethiopia t Cooperazione Italiana Universitaria, c/o Department...Geology, Addis Ababa University, Addis Ababa, Ethiopia (Received 10 October 1988; accepted 7 February...1989) Abstract - The Adola Fold and Thrust Belt of Ethiopia is a late- Precambrian, north-south trending belt...(F3), which imparted the dominant structure of the region; (4) F3 was later gently affected, at right angles | | 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...(“the lion elephant”) was extracted from the same mine [3]. Other giant crystals have been discovered in...emerald crystals was discovered in the Carnaíba mine, Brazil; the specimen weighed 341 kg with 1.7 million | | | Journal (article/letter/editorial) | and tholeiitic series rocks from Adola, southern Ethiopia B e g a s h a w W o l d e a,c,*, Z e m e n e A...Addis Ababa University, PO. Box 1176, Addis Ababa, Ethiopia I, Lege Dembi-Sakarro Primary Gold Exploration...Development Project, PO. Box 17, Shakisso, Sidamo, Ethiopia c Division of Applied Geology, Luleflt University...accepted 20 March 1996 Abstract In Adola, southern Ethiopia, mafic and ultramafic igneous rocks occur in narrow...highlight that the high-grade rocks in southern Ethiopia and northern Kenya include a significant portion | | | Journal (article/letter/editorial) | gold-quartz-tourmaline veins of the Okote area, southern Ethiopia: implications for gold exploration D. J. Deksissa...gold mineralization in the Adola Belt, southern Ethiopia. 102 D. J. Deksissa and C. Koeberl Introduction...provinces, such as in the Precambrian basement of Ethiopia (Augustithis, 1967), Brazil (Fleischer and Routhier...tourmaline is a potential path®nder mineral for source region and vein gold mineralization. The composition of...trending volcanosedimentary belts, namely the Kenticha Belt in the east and the Megado Belt in the west | | Azer, M. K., Samuel, M. D., Ali, K. A., Gahlan, H. A., Stern, R. J., Ren, M., Moussa, H. E. (2013) Neoproterozoic ophiolitic peridotites along the Allaqi-Heiani suture, South Eastern Desert, Egypt. Mineralogy and Petrology, 107 (5) 829-848 doi:10.1007/s00710-012-0204-z | Journal (article/letter/editorial) | Arabia and are suspected to exist in Eritrea, Ethiopia, and Kenya. The ANS ophiolites range in age from... This is particularly unfortunate because this region hosts the only true suture zone in Egypt, the Allaqi-Heiani-Gerf...researchers to begin studying ophiolites in this region; accordingly the significance of these rocks in...was then shortened E-W, most importantly in the region along the N-S Hamisana Shear Zone (de Wall et al...2002; Oweiss et al. 2001; Zoheir 2008; Azer 2012). Field description The present study concentrated on two | | | Journal (article/letter/editorial) | on Halaban ophiolite were focused mainly on the field works, lP except for a few published data on the...metagabbros of Halaban ophiolitic sequence, Saudi Arabia. Field, petrography, mineral chemistry and geochemistry...Halaban Neoproterozoic ophiolitic mantle section. 2. Field works The Halaban suture is a fundamental structure...is present in its northern part, and the middle region contains Halaban ophiolite. This study focuses...chlorite with minor amounts of magnetite, tremolite-actinolite, epidote, titanite, chromite and dolomite. Chlorite | | | Journal (issue) | danburite from Namalulu, Tanzania|Emerald from Ethiopia|Vivid purplish pink fluorite from Illinois, USA|...Mountains of southwest Utah, USA. The Ruby Violet mine was the only commercial source of gem-quality red...El Guanaco in the Taltal area of the Antofagasta Region, Chile. He kindly donated a 1.45 ct stone to Gem-A...mined from granitic pegmatites in the Morogoro region of central Tanzania (Chadwick and Laurs, 2008)...several weak bands were recorded in the visible region at approximately 525, 567, 577, 584, 732, 744 and | | | Report (issue) | FRONTISPIECE: Historic pump at the Wodgina tantalum–tin mine. Brought from Port Hedland by camel train about...manganotantalite crystals from Moolyella, Pilbara region. Simpson Collection, Western Australian Museum........................ 24 Regional rare-metal pegmatite zoning and lithogeochemical anomalies ................................................... 25 Pegmatite dimensions and structure .............................. 63 Bernic Lake tantalum–lithium–caesium mine ............................................... | | | Journal (article/letter/editorial) | metavolcanics (El‐ long, ~100 m‐wide elongate body at the mine area along a ~ E–W‐ Sayed, Furnes, & Mohamed, 1999)...2007). include serpentine, chlorite, tremolite‐actinolite and talc. Olivine is completely altered to serpentine...olivine besides subordinate amounts of tremolite‐actinolite, talc, chlorite and opaques. Serpentine pseudomorph...chromites, whereas the altered rims plot in the field of Cr‐magnetite dent crystals, intergrown with...Barramiya mines is con- the supra‐subduction zone field (Figure 6c). Suprasubduction fined to a ductile‐brittle | | Manu Prasanth, M.P., Hari, K.R., Chalapathi Rao, N.V., Hou, Guiting, Pandit, Dinesh (2018) An island-arc tectonic setting for the Neoarchean Sonakhan Greenstone Belt, Bastar Craton, Central India: Insights from the chromite mineral chemistry and geochemistry of the siliceous high-Mg basalts (SHMB) Geological Journal, 53 (4) 1526-1542 doi:10.1002/gj.2971 | Journal (article/letter/editorial) | rare earth elements (LREE) relative to the high field strength elements. Elevated Th/Yb ratios and negative...alteration in the host rhyolite, acid tuff, tremolite‐actinolite schist, carbonaceous argillite, rock, chromites...sporadically tectonic evolution of SGB. seen in the field. Cumulates of olivine pyroxenes and chromites &...samples were all sample plots within the SHMB field (Figure 4) have an overlap analysed at the CSIR‐National...Institute. Least with the Archean boninite‐like field. SHMB rocks from the SGB altered samples were selected | | | Book | 40Ar/39Ar Age of the Gem-Bearing Boqueirão Granitic Pegmatite, Parelhas, Rio Grande do Norte, Brazil Reprinted...Gabriele Lanzafame Gem-Quality Tourmaline from LCT Pegmatite in Adamello Massif, Central Southern Alps, Italy:...Enigmatic Alluvial Sapphires from the Orosmayo Region, Jujuy Province, Northwest Argentina: Insights...economically important gem-bearing Boqueirão granitic pegmatite situated in the Borborema Pegmatitic Province...granitic pegmatite is classified as a member of the Lithium-Caesium-Tantalum (LCT) pegmatite family and | | | Journal (issue) | M. Gressm an tgressman@comcast.n et The Musonoi mine, Kolwezi District, Lualaba Province, Democratic...COVER: METATORBERNITE, 6.6 cm, from the Musonoi mine, Kolwezi District, Democratic Republic of the Congo...April, 201 8 Prese!tt,a to Roderick Tyson For field collecting achievements contributing to the heritage...Rod Tyson has been one of the leading Canadian field collectors for decades, and has brought countless...March-April, 2018 Record, in recognition of his field-collecting achievements contributing to the Heritage | | | Journal (issue) | Scapolite from Brazil | Spessartine Reportedly from Ethiopia | Diamond Mining at Theindaw, Myanmar | Early...and Their Composition in Ruby from the Bo Rai Gem Field in Trat Province, Eastern Thailand By Supparat Promwongnan...in the 450–500 nm region that is bounded by absorption bands in the visible region that arise from the...mineralogically variable matrix of phlogopite, muscovite, actinolite, plagioclase and pyrite, with occasional quartz...Be-, F- and Na-bearing fluids from an unexposed pegmatite dyke or hydrothermal vein, with later overprinting |
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