Hostname: page-component-76fb5796d-x4r87 Total loading time: 0 Render date: 2024-04-25T07:49:18.028Z Has data issue: false hasContentIssue false
  • English
  • Français

Accretion tectonics in northern Eritrea revealed by remotely sensed imagery

Published online by Cambridge University Press:  01 May 2009

S. A. Drury  and
S. M. Berhe
S. A. Drury
Affiliation:
Department of Earth Sciences, The Open University, Milton Keynes MK7 6AA, U.K.
S. M. Berhe
Affiliation:
Department of Earth Sciences, The Open University, Milton Keynes MK7 6AA, U.K.
Get access Rights & Permissions [Opens in a new window]

Abstract

New details from remotely sensed images of the structure and disposition of broad lithological variations in the Pan-African of northern Eritrea are discussed in the context of accretionary tectonics. The recognition of major north-south structural discontinuities allows the area to be divided into three discrete terranes with apparently different histories of deformation and metamorphism, magmagenesis and sedimentation. The central Hagar Terrane is dominated by large ultramafic masses with a volcano-sedimentary layered sequence, and shows the effects of major sinistral transpression and lateral expulsion. It is bounded to the west by a major fault, the Barka suture, and abuts the older Barka Terrane that comprises metasediments with evidence for polyphase ductile deformation and pre-kinematic dyke emplacement. The Hagar Terrane is thrust against the eastern Nacfa Terrane, which is dominated by low-grade calc-alkaline metavolcanics and immature volcanoclastic sediments intruded by syn-kinematic plutons. These units are pre-dated by an earlier high-grade basement and post-dated by high-level unmetamorphosed silicic volcanics and redbed sediments. The complex is suggested to have been assembled by oblique accretion from the southeast after arc volcanism in the Nacfa Terrane and back-arc extension in the Hagar Terrane ended with the cease of subduction.

Type
Articles
Information
Geological Magazine , Volume 130 , Issue 2 , March 1993 , pp. 177 - 190
Copyright
Copyright © Cambridge University Press 1993

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Abrams, M. J., Rothery, D. A. & Pontual, A. 1988. Mapping in the Oman ophiolite using enhanced Landsat Thematic Mapper images. Tectonophysics 151, 387–401.CrossRefGoogle Scholar
Berhe, S. M. 1990. Ophiolites in Northeastern and East Africa: implications for Proterozoic crustal growth. Journal of the Geological Society 147, 41–57.CrossRefGoogle Scholar
Calvez, Y. J., Alsac, C, Delfour, J., Kemp, J. & Pellaton, C. 1983. Geological evolution of western, central and eastern parts of the northern Precambrian Shield, Kingdom of Saudi Arabia. Saudi Arabian Deputy Ministry for Mineral Resources Open File Report BRGM-OF-03–17.Google Scholar
Claesson, S., Pallister, J. S. & Tatsumoto, M. 1984. Sm-Nd data on two late-Proterozoic ophiolites of Saudi Arabia and implications for crustal and mantle evolution. Contributions to Mineralogy and Petrology 85, 244–52.CrossRefGoogle Scholar
Delfour, J. 1980. Geologic, tectonic and metallogenic evolution of the northern part of the Precambrian Arabian Shield (Kingdom of Saudi Arabia). Bulletin de BRGM 11, 1–20.Google Scholar
Dixon, T. H. & Golombek, M. P. 1988. Late Precambrian crustal accretion rates in northeast Africa and Arabia. Geology 16, 991–4.2.3.CO;2>CrossRefGoogle Scholar
Drury, S. A. 1987. Image Interpretation in Geology. London: Allen and Unwin, 243 pp.CrossRefGoogle Scholar
Drury, S. A. 1990. SPOT image data as an aid to structural mapping in the southern Aravalli Hills of Rajasthan, India. Geological Magazine 127, 195–207.CrossRefGoogle Scholar
Francaviglia, T. I. 1939. Note sulla constituzione geologica della zona del basso Barca. Giornale di Geologia (Bologna) Ser 2a 13, 23–7.Google Scholar
Gass, I. G. 1977. The evolution of the Pan-African crystalline basement in NE Africa and Arabia. Journal of the Geological Society 134, 129–38.CrossRefGoogle Scholar
Gass, I. G. 1981. Pan-African (Upper Proterozoic) plate tectonics of the Arabian-Nubian Shield. In Precambrian Plate Tectonics (ed. Kroner, A.), pp. 387–405. Amsterdam: Elsevier.Google Scholar
Greenwood, W. R., Anderson, R. E., Fleck, R. J. & Roberts, R. J. 1980. Precambrian geologic history and plate tectonic evolution of the Arabian Shield. Bulletin of the Saudi Arabian Directorate General of Mineral Resources 24.Google Scholar
Gras (Geological Research Authority of Sudan) 1988. Geological map of NE Sudan (Port Sudan/Tokar): 1:1 million. No. 10.Google Scholar
Harris, N. B. W., Gass, I. G. & Hawkesworth, C. J. 1990. A geochemical approach to allochthonous terranes: a Pan-African case study. Philosophical Transactions of the Royal Society, London, Series A 331, 533–48.Google Scholar
Kazmin, V. 1973. Geological map of Ethiopia, Scale 1:2,000,000. Ethiopian Ministry of Mines.Google Scholar
Kemp, J., Pellaton, C. & Calvez, J. V. 1980. Geochronological investigations and geological history in the Precambrian of north-western Saudi Arabia. BRGM, Open File 01–1.Google Scholar
Kennedy, W. Q. 1964. The structural differentiation of Africa in the Pan-African (+500 my) episode. University of Leeds Research Institute of African Geology, Department of Earth Sciences Annual Report 8, 48–9.Google Scholar
Kröner, A. 1979. Pan-African mobile belts as evidence for a transitional tectonic regime from intraplate orogeny to plate margin orogeny. In Evolution of the Arabian-Nubian Shield vol. 1 (ed. Shanti, A. M.S. Al), pp. 21–37. Institute of Applied Geology Research Bulletin 3.CrossRefGoogle Scholar
Kröner, A. 1985. Ophiolites and the evolution of tectonic boundaries in the late-Proterozoic Arabian-Nubian Shield of northeast Africa and Arabia. Precambrian Research 27, 277–300.CrossRefGoogle Scholar
Kröner, A., Greiling, R., Reischman, T., Hussein, I. M., Stern, R. J., Dürr, S., Kruger, J. & Zimmer, M. 1987. Pan-African crustal evolution in the Nubian segment of northeast Africa. In Proterozoic Lithospheric Evolution (ed. Kröner, A.) pp. 235–57. Geodynamics Series Volume 17. International Lithosphere Program Contribution, AGU, Washington, DC.CrossRefGoogle Scholar
Kröner, A., Linnebacher, P., Stern, R. J., Reischman, T., Manton, W. & Hussein, I. M. 1991. Evolution of Pan-African island arc assemblages in the southern Red Sea Hills, Sudan, and in southwestern Arabia as exemplified by geochemistry and geochronology. Precambrian Research 53, 99–118.CrossRefGoogle Scholar
Mohr, P. 1979. Lithology and structure of the Precambrian rocks of Eritrea. Bulletin of the Institute of Applied Geology, Jeddah 2, 7–15.Google Scholar
Oldow, J. S., Bally, A. W., Ave Lallemant, H. G. & Leeman, W. P. 1989. Phanerozoic evolution of the North American Cordillera; United States and Canada. In The geology of North America - an overview, volume A, pp. 139–232. Geological Society of America Special Publication.CrossRefGoogle Scholar
Ramsay, J. G. 1967. Folding and Fracturing of Rocks. San Francisco: McGraw-Hill, 426 pp.Google Scholar
Stacey, J. S. & Hedge, C. E. 1984. Geochronologic and isotopic evidence for early Proterozoic crust in the eastern Arabian Shield. Geology 12, 310–13.2.0.CO;2>CrossRefGoogle Scholar
Stacey, J. S. & Stoeser, D. B. 1983. Distribution of oceanic and continental leads in the Arabian-Nubian Shield. Contributions to Mineralogy and Petrology 84, 91–105.CrossRefGoogle Scholar
Stern, R. J. 1981. Petrogenesis and tectonic setting of late-Precambrian ensimatic volcanic rocks, central Eastern Desert of Egypt. Precambrian Research 16, 195–230.CrossRefGoogle Scholar
Stoeser, D. B. & Camp, V. E. 1985. Pan-African microplate evolution of the Arabian Shield. Geological Society of America Bulletin 96, 817–26.2.0.CO;2>CrossRefGoogle Scholar
Sugden, T. 1987. Kinematic indicators: structures that record the sense of movement in mountain chains. Geology Today 4, 93–9.CrossRefGoogle Scholar
Sultan, M., Arvidson, R. E. & Sturchio, N. C. 1986. Mapping of serpentinites in the Eastern Desert of Egypt by using Landsat Thematic Mapper data. Geology 14, 995–9.2.0.CO;2>CrossRefGoogle Scholar
Sultan, M., Chamberlain, K. R., Bowring, S. A., Arvidson, R. E., Abuzied, H. & El Kalioubi, B. 1990. Geochronologic and isotopic evidence for involvement of pre-Pan-African crust in the Nubian Shield, Egypt. Geology 18, 761–4.2.3.CO;2>CrossRefGoogle Scholar
Sultan, M., Becker, R., Arvidson, R. E., Shore, P., Stern, R. J., El Alfy, Z. & Guinness, E. A. 1992. Nature of the Red Sea crust: a controversy revisited. Geology 20, 593–96.2.3.CO;2>CrossRefGoogle Scholar
Vail, J. R. 1985. Pan-African (late Precambrian) tectonic terrains and the reconstruction of the Arabian-Nubian Shield. Geology 13, 839–42.2.0.CO;2>CrossRefGoogle Scholar