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Journal Article

U-Pb and Rb-Sr geochronology of the Western Ethiopian Shield Available to Purchase

TEKLEWOLD AYALEW, KEITH BELL, JOHN M. MOORE, RANDALL R. PARRISH
Journal: GSA Bulletin
Published: 01 September 1990
GSA Bulletin (1990) 102 (9): 1309–1316.
DOI: https://doi.org/10.1130/0016-7606(1990)102<1309:UPARSG>2.3.CO;2
...TEKLEWOLD AYALEW; KEITH BELL; JOHN M. MOORE; RANDALL R. PARRISH Abstract Five U-Pb zircon and four Rb-Sr whole-rock isochron dates constrain the ages of plutonic rocks and their subsequent history within the Western Ethiopian Shield. The U-Pb data show plutonic activity between 830 and 540 Ma...
View PDF for article title, U-Pb and Rb-Sr geochronology of the Western <span class="search-highlight">Ethiopian</span> <span class="search-highlight">Shield</span>
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Gold occurrences and producing mines plotted on a simplified map of Precambrian geology in western and southern Ethiopia. Gold occurrences afterTadesse et al. (2003); geology after “Geology of Ethiopia”, Ethiopian Ministry of Mines, Geological Survey of Ethiopia. Subdivisions of the Western Ethiopian Shield after Woldemichael et al. (2009): WMGT=western migmatitic high-gradegneissic terrane, CVST=central volcano-sedimentary terrane, EMGT=eastern migmatitic high-grade gneissic terrane. Subdivision of the Southern Ethiopian Shield after Tsige and Abdelsalam (2005). Inset schematically shows the structural setting of gold occurrences in the Southern Ethiopian shield, with a concentration of mineralization between sinistral and dextral shear zones (after Worku and Schandelmeier; 1996).

Gold occurrences and producing mines plotted on a simplified map of Precamb... Available to Purchase

Published: 01 March 2017
of the Western Ethiopian Shield after Woldemichael et al. (2009) : WMGT=western migmatitic high-gradegneissic terrane, CVST=central volcano-sedimentary terrane, EMGT=eastern migmatitic high-grade gneissic terrane. Subdivision of the Southern Ethiopian Shield after Tsige and Abdelsalam (2005) . Inset
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Simplified geological map of the Arabian–Nubian shield (modified after Worku &amp; Schandelmeier 1996; Fritz et al. 2013; Blades et al. 2015) with the study area indicated (Fig. 2). The Gulf of Aden fracture zones are after Bosworth et al. (2005). Inset shows the location of the Arabian–Nubian Shield (ANS) and Mozambique Belt (MB) within the East African Orogen (Abdelsalam et al. 2008). WES, Western Ethiopian Shield; SES, Southern Ethiopian Shield; NED, Northern Eastern Desert; CED, Central Eastern Desert; SED, Southern Eastern Desert.

Simplified geological map of the Arabian–Nubian shield (modified after Wor... Available to Purchase

Published: 22 July 2016
of the Arabian–Nubian Shield (ANS) and Mozambique Belt (MB) within the East African Orogen ( Abdelsalam et al. 2008) . WES, Western Ethiopian Shield; SES, Southern Ethiopian Shield; NED, Northern Eastern Desert; CED, Central Eastern Desert; SED, Southern Eastern Desert.
Journal Article

Zircon U–Pb ages, δ 18 O and whole-rock Nd isotopic compositions of the Dire Dawa Precambrian basement, eastern Ethiopia: implications for the assembly of Gondwana Available to Purchase

Fitsum Girum Yeshanew, Victoria Pease, Mohamed G. Abdelsalam, Martin J. Whitehouse
Published: 22 July 2016
Journal of the Geological Society (2017) 174 (1): 142–156.
DOI: https://doi.org/10.1144/jgs2016-017
... of the Arabian–Nubian Shield (ANS) and Mozambique Belt (MB) within the East African Orogen ( Abdelsalam et al. 2008) . WES, Western Ethiopian Shield; SES, Southern Ethiopian Shield; NED, Northern Eastern Desert; CED, Central Eastern Desert; SED, Southern Eastern Desert. ...
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View PDF for article title, Zircon U–Pb ages, δ 18 O and whole-rock Nd isotopic compositions of the Dire Dawa Precambrian basement, eastern Ethiopia: implications for the assembly of Gondwana
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(a) Map of Gondwana showing the overall geological setting (modified after Torsvik &amp; Cocks 2013). (b) Map of Eastern Africa and Arabia showing exposures of Precambrian rocks and major tectonic units (modified after Fritz et al. 2013). ANS, Arabian–Nubian Shield; B, Bangweulu; CC, Congo Craton; IB, Irumide Belt; SES, Southern Ethiopian Shield; TC, Tanzania Craton; UB, Ubendian Belt; US, Usagaran Belt; WES, Western Ethiopian Shield; WG, Western Granulite Belt; ZKC, Zimbabwe–Kalahari Craton. References for age information: (1) Teklay et al. (1998); (2) Woldemichael et al. (2010); (3) Kebede et al. (2001); (4) Kröner et al. (2003); (5) Bingen et al. (2009); (6) Mänttäri (2014); (7) Fritz et al. (2013); (8) Johnson et al. (2011).

( a ) Map of Gondwana showing the overall geological setting (modified afte... Available to Purchase

Published: 13 September 2019
; CC, Congo Craton; IB, Irumide Belt; SES, Southern Ethiopian Shield; TC, Tanzania Craton; UB, Ubendian Belt; US, Usagaran Belt; WES, Western Ethiopian Shield; WG, Western Granulite Belt; ZKC, Zimbabwe–Kalahari Craton. References for age information: (1) Teklay et al. (1998) ; (2) Woldemichael et
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Schematic illustration of the development of Daleti, Tulu Dimtu, Abshala and Yubdo in the Western Ethiopian Shield. Subduction and intra-oceanic arc magmatism is initiated at 854 Ma followed by deformation and further magmatism between 750 and 660 Ma. Closure of the Mozambique Ocean and amalgamation of terranes in the northern East African Orogen is completed by 520 Ma.

Schematic illustration of the development of Daleti, Tulu Dimtu, Abshala an... Available to Purchase

Published: 30 October 2017
Figure 11. Schematic illustration of the development of Daleti, Tulu Dimtu, Abshala and Yubdo in the Western Ethiopian Shield. Subduction and intra-oceanic arc magmatism is initiated at 854 Ma followed by deformation and further magmatism between 750 and 660 Ma. Closure of the Mozambique Ocean
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TiO2 content versus Cr# in spinel from ultramafic rocks of the Western Ethiopian Shield. Spinel compositions of MORB, island-arc basalts (IAB) and boninites are from Arai (1992), Kelemen et al. (1995) and Dick &amp; Natland (1996). Supra-subduction zone (SSZ) peridotites from Oman were taken from Arai et al. (2006). Chrome spinels are seen in a number of fields but predominately in boninite, SSZ (Oman) and IAB.

TiO 2 content versus Cr# in spinel from ultramafic rocks of the Western Et... Available to Purchase

Published: 30 October 2017
Figure 7. TiO 2 content versus Cr# in spinel from ultramafic rocks of the Western Ethiopian Shield. Spinel compositions of MORB, island-arc basalts (IAB) and boninites are from Arai ( 1992 ), Kelemen et al. ( 1995 ) and Dick & Natland ( 1996 ). Supra-subduction zone (SSZ) peridotites from
Journal Article

Propos sur le Pan-Africain Available to Purchase

R. Black
Published: 01 January 1978
Bulletin de la Société Géologique de France (1978) S7-XX (6): 843–850.
DOI: https://doi.org/10.2113/gssgfbull.S7-XX.6.843
...R. Black GeoRef, Copyright 2004, American Geological Institute. 1978 accretion Africa African Plate Arabian Peninsula Arabian Shield Asia cratons current research Ethiopian Shield extent Mali Morocco North Africa ophiolite orogeny paleomagnetism Pan-African Orogeny plate...
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Thin-sections of the ultramafic samples collected from the Western Ethiopian Shield (WES). (a, b) Sections from Daleti Quarry (E13-11); (a) is plane polar and (b) is in cross-polar. The primary mineralogy consists of olivine and Cr spinel. Extensive alteration: serpentine forms a mesh texture, resembling a fisherman's net, where the rim of the net is serpentine and the empty space in the mesh centre is occupied by fresh (relict) olivine. (c, d) Representative section of Abshala Melange and Tulu Dimtu Hill (E13-19, 20, 22 and 26); (c) is plane polar and (d) is in cross-polar. These samples have been more extensively altered with no relict/fresh olivines seen within this sample. The dunite contains chrome spinels with euhedral to subhedral shapes. All silicate minerals within the sample have been altered by serpentine. (e, f) Sample was taken from Yubdo (E13-10); (e) is plane polar and (f) is in cross-polar. The spinels are subhedral spinels and occur in serpentine-filled cracks. The olivines are fresh with little evidence for serpentinization other than in the cracks between these minerals.

Thin-sections of the ultramafic samples collected from the Western Ethiopia... Available to Purchase

Published: 30 October 2017
Figure 3. Thin-sections of the ultramafic samples collected from the Western Ethiopian Shield (WES). (a, b) Sections from Daleti Quarry (E13-11); (a) is plane polar and (b) is in cross-polar. The primary mineralogy consists of olivine and Cr spinel. Extensive alteration: serpentine forms a mesh
Journal Article

Provenance of Ordovician–Silurian and Carboniferous–Permian glaciogenic successions in Ethiopia revealed by detrital zircon U–Pb geochronology Available to Purchase

Anna Lewin, Guido Meinhold, Matthias Hinderer, Enkurie L. Dawit, Robert Bussert, Jasper Berndt
Published: 13 September 2019
Journal of the Geological Society (2020) 177 (1): 141–152.
DOI: https://doi.org/10.1144/jgs2019-027
...; CC, Congo Craton; IB, Irumide Belt; SES, Southern Ethiopian Shield; TC, Tanzania Craton; UB, Ubendian Belt; US, Usagaran Belt; WES, Western Ethiopian Shield; WG, Western Granulite Belt; ZKC, Zimbabwe–Kalahari Craton. References for age information: (1) Teklay et al. (1998) ; (2) Woldemichael et...
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View PDF for article title, Provenance of Ordovician–Silurian and Carboniferous–Permian glaciogenic successions in Ethiopia revealed by detrital zircon U–Pb geochronology
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Journal Article

Gold-bearing volcanogenic massive sulfides and orogenic-gold deposits in the Nubian Shield Available to Purchase

P.R. Johnson, B.A. Zoheir, W. Ghebreab, R.J. Stern, C.T. Barrie, R.D. Hamer
Published: 01 March 2017
South African Journal of Geology (2017) 120 (1): 63–76.
DOI: https://doi.org/10.25131/gssajg.120.1.63
... of the Western Ethiopian Shield after Woldemichael et al. (2009) : WMGT=western migmatitic high-gradegneissic terrane, CVST=central volcano-sedimentary terrane, EMGT=eastern migmatitic high-grade gneissic terrane. Subdivision of the Southern Ethiopian Shield after Tsige and Abdelsalam (2005) . Inset...
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View PDF for article title, Gold-bearing volcanogenic massive sulfides and orogenic-gold deposits in the Nubian <span class="search-highlight">Shield</span>
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Journal Article

Geology, geochronology and geodynamic implications of the Cenozoic magmatic province in W and SE Ethiopia Available to Purchase

S. M. Berhe, B. Desta, M. Nicoletti, M. Teferra
Published: 01 April 1987
Journal of the Geological Society (1987) 144 (2): 213–226.
DOI: https://doi.org/10.1144/gsjgs.144.2.0213
...S. M. Berhe; B. Desta; M. Nicoletti; M. Teferra Abstract New K-Ar dates are presented for areas in W and SE Ethiopia. In the west, the dates distinguish the Geba Basalts of 40 to 32 Ma (previously determined by Merla et al. 1979) from the Welega Shield Volcanics which are shown to range from 11.2...
View PDF for article title, Geology, geochronology and geodynamic implications of the Cenozoic magmatic province in W and SE Ethiopia
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The origin of the ultramafic rocks of the Tulu Dimtu Belt, western Ethiopia – do they represent remnants of the Mozambique Ocean? Available to Purchase

MORGAN L. BLADES, JOHN FODEN, ALAN S. COLLINS, TADESSE ALEMU, GIRMA WOLDETINSAE
Published: 30 October 2017
Geological Magazine (2019) 156 (1): 62–82.
DOI: https://doi.org/10.1017/S0016756817000802
...Figure 11. Schematic illustration of the development of Daleti, Tulu Dimtu, Abshala and Yubdo in the Western Ethiopian Shield. Subduction and intra-oceanic arc magmatism is initiated at 854 Ma followed by deformation and further magmatism between 750 and 660 Ma. Closure of the Mozambique Ocean...
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View PDF for article title, The origin of the ultramafic rocks of the Tulu Dimtu Belt, western Ethiopia – do they represent remnants of the Mozambique Ocean?
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Journal Article

Integrated geological-architectural pilot study of the Biet Gabriel-Rufael rock hewn church in Lalibela, northern Ethiopia Available to Purchase

Federico Sani, Giovanna Moratti, Massimo Coli, Pietro Laureano, Luisa Rovero, Ugo Tonietti, Niccolò Coli
Published: 27 March 2012
Italian Journal of Geosciences (2012) 131 (2): 171–186.
DOI: https://doi.org/10.3301/IJG.2011.26
... and deeper level; e ) location of d ). The town of Lalibela is built on a geological substratum belonging to the Ethiopian Plateau suite, which is composed of two main different typologies of rocks: flood basalts, mainly interpreted as of fissure origin, and shield basalts, emplaced from shield...
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View PDF for article title, Integrated geological-architectural pilot study of the Biet Gabriel-Rufael rock hewn church in Lalibela, northern Ethiopia
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High-precision olivine minor and trace element data for South Island compared with other datasets: MORB, Afar, within-plate basalt (WPM – thick) (Sobolev et al. 2007); ugandites (Foley et al. 2011); melanephelinite, basanite and alkali basalts from the Miocene Gerba Guracha Shield volcano on the Ethiopian highlands (Rooney et al. 2017); and Ethiopian flood basalt (Rooney et al. 2017). South Island olivine data are distinct from olivine data derived from metasomatically enriched sources. The low Cr values in South Island olivine compared with the other datasets is notable.

High-precision olivine minor and trace element data for South Island compar... Free

Published: 24 August 2022
Fig. 7. High-precision olivine minor and trace element data for South Island compared with other datasets: MORB, Afar, within-plate basalt (WPM – thick) ( Sobolev et al. 2007 ); ugandites ( Foley et al. 2011 ); melanephelinite, basanite and alkali basalts from the Miocene Gerba Guracha Shield
Journal Article

A detrital record of the Nile River and its catchment Open Access

Laura Fielding, Yani Najman, Ian Millar, Peter Butterworth, Sergio Ando, Marta Padoan, Dan Barfod, Ben Kneller
Published: 07 December 2016
Journal of the Geological Society (2017) 174 (2): 301–317.
DOI: https://doi.org/10.1144/jgs2016-075
.... 1998 ), Neoproterozoic Arabian–Nubian Shield basement rocks (e.g. Evuk et al. 2014 ; Johnson 2014 ) and Phanerozoic cover sequences (e.g. Gani et al. 2009 ). Uplift of the Ethiopian Highlands in the Oligocene may have led to the initiation of flow in the Blue Nile. However, there is no consensus...
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Representative chrome spinel and co-existing olivine microprobe analyses fr... Available to Purchase

Published: 30 October 2017
Table 1. Representative chrome spinel and co-existing olivine microprobe analyses from ultramafic rocks of the Western Ethiopian Shield ID number E14-10 E13-11 E14-19 E13-20 E13-22 E13-26 SiO 2 0.08 0.01 < 0.01 0.02 0.01 0.01 TiO 2 0.38 0.01 0.01 < 0.01
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Geological map of the northern part of the Ethiopian plateau showing the extent and distribution of shield volcanoes and underlying flood basalts (modified from Pik et al. 1998; Ayalew et al. 2002); locality of the studied peridotite xenoliths denoted by small circle.

Geological map of the northern part of the Ethiopian plateau showing the ex... Available to Purchase

Published: 06 November 2008
Figure 1. Geological map of the northern part of the Ethiopian plateau showing the extent and distribution of shield volcanoes and underlying flood basalts (modified from Pik et al. 1998 ; Ayalew et al. 2002 ); locality of the studied peridotite xenoliths denoted by small circle.
Journal Article

Northward expulsion of the Pan-African of northeast Africa guided by a reentrant zone of the Tanzania craton Available to Purchase

F. F. Bonavia, J. Chorowicz
Journal: Geology
Published: 01 November 1992
Geology (1992) 20 (11): 1023–1026.
DOI: https://doi.org/10.1130/0091-7613(1992)020<1023:NEOTPA>2.3.CO;2
...), the region of transition is interpreted to represent the root of northward expulsion of the Arabian-Nubian shield from the Mozambique orogenic belt. In this region, the northwest-trending late Mesozoic Kenyan rift, the Cenozoic Northern Kenyan rift, and the Main Ethiopian rift form a rift complex across Pan...
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Map of the sampling area on the Ethiopian plateau, indicating the locations of the flood basalt deposits, Mt. Choke volcanic shield deposits and sampling sites. Geological Survey of Ethiopia, Debre Markos sheet map, NC37-6, age data from Hofman et al. (1997), Coulié et al. (2003), and Kieffer et al. (2004).

Map of the sampling area on the Ethiopian plateau, indicating the locations... Open Access

Published: 01 November 2015
Figure 1 Map of the sampling area on the Ethiopian plateau, indicating the locations of the flood basalt deposits, Mt. Choke volcanic shield deposits and sampling sites. Geological Survey of Ethiopia, Debre Markos sheet map, NC37-6, age data from Hofman et al. (1997) , Coulié et al. (2003