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Western Ethiopian Shield

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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 <span class="search-highlight">Western</span> <span class="search-highlight">Ethiopian</span> <span class="search-highlight">Shield</span>
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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
... mostly derived from reworking of long-lived crustal sources. The occurrence of c . 580 – 550 Ma orogenesis in both the Dire Dawa basement and the juvenile Western Ethiopian Shield and the confinement of c . 630 Ma metamorphism to only the latter indicate that these two lithospheric blocks of contrasting...
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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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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.
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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
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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

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, <span class="search-highlight">western</span> Ethiopia – do they represent remnants of the Mozambique Ocean?
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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
Journal Article

Detrital zircon U–Pb–Hf systematics of Israeli coastal sands: new perspectives on the provenance of Nile sediments Available to Purchase

Y. Be’eri-Shlevin, D. Avigad, A. Gerdes, O. Zlatkin
Published: 23 October 2013
Journal of the Geological Society (2014) 171 (1): 107–116.
DOI: https://doi.org/10.1144/jgs2012-151
... , 21 , 690 – 703 . Ayalew T. Bell K. Moore J.M. Parrish R.R. 1990 . U–Pb and Rb–Sr geochronology of the Western Ethiopian Shield . Geological Society of America Bulletin , 102 , 1309 – 1316 . Batumike J.M. Griffin W.L. O’Reilly S.W. Belousova...
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View PDF for article title, Detrital zircon U–Pb–Hf systematics of Israeli coastal sands: new perspectives on the provenance of Nile sediments
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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

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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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
...—revisited in Western Afar Processes of Continental Rifting Tectonophysics 1983a 94 509 28 Mohr P. The Ethiopian flood basalt province Nature 1983b 303 577 84 Mohr P. Perspectives on the Ethiopian Volcanic Province Bulletin Volcanologique 1983c 46 23 43 Mohr P...
View PDF for article title, Geology, geochronology and geodynamic implications of the Cenozoic magmatic province in W and SE Ethiopia
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Journal Article

Crustal contribution to the genesis of Ethiopian plateau rhyolitic ignimbrites: basalt and rhyolite geochemical provinciality Available to Purchase

Dereje Ayalew, Gezahegn Yirgu
Published: 01 January 2003
Journal of the Geological Society (2003) 160 (1): 47–56.
DOI: https://doi.org/10.1144/0016-764901-169
... flood basalts . Geochimica et Cosmochimica Acta , 66 , 1429 – 1448 . Ayalew , T. , Bell , K. , Moore , K. & Parrish , R. 1990 . U–Pb and Rb–Sr geochronology of the western Ethiopian shield . Geological Society of America Bulletin , 102 , 1309 – 1316 . Baker...
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View PDF for article title, Crustal contribution to the genesis of <span class="search-highlight">Ethiopian</span> plateau rhyolitic ignimbrites: basalt and rhyolite geochemical provinciality
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A new mantle xenolith locality from Simien shield volcano, NW Ethiopia Available to Purchase

DEREJE AYALEW, NICK ARNDT, FLORENCE BASTIEN, GEZAHEGN YIRGU, BRUNO KIEFFER
Published: 06 November 2008
Geological Magazine (2009) 146 (1): 144–149.
DOI: https://doi.org/10.1017/S0016756808005785
...DEREJE AYALEW; NICK ARNDT; FLORENCE BASTIEN; GEZAHEGN YIRGU; BRUNO KIEFFER Abstract Thin-section observations and electron probe analyses, and trace element data are reported from a new mantle xenolith hosted in Miocene alkali basalt from the western flank of Simien shield volcano, Ethiopia...
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View PDF for article title, A new mantle xenolith locality from Simien <span class="search-highlight">shield</span> volcano, NW Ethiopia
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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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The role of continental lithosphere metasomes in the production of HIMU-like magmatism on the northeast African and Arabian plates Available to Purchase

Tyrone O. Rooney, Wendy R. Nelson, Laure Dosso, Tanya Furman, Barry Hanan
Journal: Geology
Published: 01 May 2014
Geology (2014) 42 (5): 419–422.
DOI: https://doi.org/10.1130/G35216.1
... the developing rift. We focus on a suite of lavas erupted from a Miocene shield volcano near Gerba Guracha on the western Ethiopian plateau ( Fig. 1 ). Major and trace element whole-rock data were obtained on eight samples of the Gerba Guracha lavas using X-ray fluorescence and laser ablation–inductively...
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Quaternary off-rift volcanism along a section of the East African Rift System (EARS), from the south Ethiopia to the south Kenya Available to Purchase

Francesco Mazzarini, Ilaria Isola
Published: 01 October 2022
Italian Journal of Geosciences (2022) 141 (3): 334–347.
DOI: https://doi.org/10.3301/IJG.2022.19
... to the present, the progressive decrease in magmatic activity is characterized by initial fissural basalts, to a series of large shield volcanoes, to modern belts of cinder cones and is mainly represented in the Main Ethiopian Rift, Afar and north Kenya Rift ( Rooney, 2020a ). The above described magmatic...
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View PDF for article title, Quaternary off-rift volcanism along a section of the East African Rift System (EARS), from the south Ethiopia to the south Kenya
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