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Magnetostratigraphy of the lower member of the hadar formation (Ethiopia): Evidence for a short normal event in the mammoth subchron

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Summary

Rock magnetism and magnetostratigraphy of the lower part of the Hadar Formation (Afar, Ethiopia) is presented after analysis of multiple new collection of samples from over 84 horizons. The Hadar Formation is composed of lacustrine, lake margin, fluvial and flood plain sediments and known for important Pliocene vertebrate faunas including Australopithecus afarensis. Hysteresis measurements, thermomagnetic analysis, growth and decay of isothermal remanent magnetisation are used to unravel the complex magnetic mineralogy of the different representative lithologies. Ferrimagnetic minerals of magnetite or titanomagnetite in composition, in the stable pseudo-single domain (PSD) size range are found to be the main carriers of the remanence. In most sites the characteristic remanence was isolated using stepwise thermal demagnetisation. The overall mean direction for about 72 horizons (434 samples) is D=358·6°, I=7° (k=17·9, α95=4°) implying some 14° of inclination shallowing, related to sediment compaction due to the very rapid sedimentation history of the site. Five successive polarity zones (N1-R1-N2-R2-N3) are identified and correlation with the lower Gauss chron of the astronomically calibrated geomagnetic polarity time scale (GPTS) is proposed using the existing40Ar/39Ar ages. This implies the existence of a short normal polarity event (N2), identified on six different sites, within the reversed Mammoth subchron, called the Kada-Hadar event. The age calculated for the Kada-Hadar event, using linear interpolation of the dated horizons, assuming a constant rate of sedimentation is 3.246 Ma and its duration is about 8 kyr.

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References

  • Aronson J.L., Schmitt T.J., Walter R.C., Taieb M., Tiercelin J.J., Johanson D.C., Naeser C.W. and Nairn A.E.M., 1977: New geochronologic and palaeomagnetic data for the hominid bearing Hadar Formation of Ethipia.Nature 267, 323–327.

    Article  Google Scholar 

  • Aronson J.L. and Taieb M., 1981: Geology and palaeogeography of the Hadar hominid site, Ethiopia, In: J.G. Rapp and C.F. Vondra (eds.),Hominid sites: Their geologic settings, Boulder, Colorado, Westview, pp. 165–195.

    Google Scholar 

  • Barberi F., Borosi S., Ferrara G., Marinelli G., Santacroce R., Tazieff H. and Varet J., 1972: Evolution of the Danakil Depression (Afar, Ethiopia), in light of radiometric determinations.Geol. J. 80, 720–729.

    Google Scholar 

  • Bloemendal J., King J., Hall F.R. and Doh S.J., 1992: Rock magnetisma of Late Neogene and Pleistocene deep-sea sediments: relationship to sediment source, diagenetic processes and sediment lithology.J. Geophys. Res. 97, 4361–4375.

    Google Scholar 

  • Boaz N.T., Howell F.C. and McCrossin M.L., 1982: Faunal age of the Usno, Shungura B and Hadar Formations, Ethiopia.Nature 300, 633–635.

    Article  Google Scholar 

  • Brown F.H., 1982: Tulu Bor Tuff at Koobi Fora correlated with the Sidi Hakoma Tuff at Hadar.Nature 300, 631–633.

    Google Scholar 

  • Champion D.E., Lanphere M.A. and Kuntz M.A., 1988: Evidence for a new geomagnetic reversal from lava flows in Idaho: Discussion of short polarity reversals in the Brunhes and late Matuyama polarity chrons.J. Geophys. Res. 93, 11667–11680.

    Google Scholar 

  • Day R., Fuller M. and Schmidt V.A., 1977: Hysteresis properties of titanomagnetites: Grain size and compositional dependence.Phys. Earth Planet. Inter. 13, 260–267.

    Google Scholar 

  • Fisher R.A., 1953: Dispersion on a sphere.Proc. R. Soc. London Ser.A 217, 295–305.

    Google Scholar 

  • Hilgen F.J., 1991: Astronomical calibration of Gauss to Matuyama Sapropels in the Mediterranean and implication for the Geomagnetic Polarity Time Scale.Earth Planet. Sci. Lett. 104, 226–244.

    Article  Google Scholar 

  • Hillaire M.H., Taieb M., Tiercelin J.J. and Page N., 1982: A 1·2 Myr. record of isotopic changes in a late Pliocene rift lake, Ethiopia.Nature 296, 640–642.

    Google Scholar 

  • Hrouda F., 1994: A technique for the measurement of thermal changes of magnetic susceptibility of weakly magnetic rocks by the CS-2 apparatus and KLY-2 kappabridge.Geophys. J. Int. 118, 604–612.

    Google Scholar 

  • Jelínek V., 1980: Kappabridge KLY-2.A precision laboratory bridge for measuring magnetic susceptibility of rocks (including anisotropy). Geofyzika, Brno.

    Google Scholar 

  • Johanson D.C. and Taieb M., 1976: Plio-pleistocene hominid discoveries in Hadar, Ethiopia,Nature 260, 293–297.

    Article  Google Scholar 

  • Kirschvink J.L., 1980: The least squares line and plane and the analysis of paleomagnetic data.Geophys. J. R. Astron. Soc. 62, 699–718.

    Google Scholar 

  • Liddicoat J.C., Opdyke N.D. and Smith G.I., 1980: Palaeomagnetic polarity in a 930-m core from Searles Valley, California.Nature 286, 22–25.

    Article  Google Scholar 

  • Lowrie W., 1990: Identification of ferrimagnetic minerals in a rock by coercivity and unblocking temperature properties.Geophys. Res. Lett. 17, 159–162.

    Google Scholar 

  • McDougall I., Saemundson K., Johannesson H., Watkins N.D., and Kritjansson L., 1977: Extension of the geomagnetic polarity time scale to 6·5 Myr.: K-Ar dating, geological and paleomagnetic study of a 3500 m lava succession in western Iceland.Geol. Soc. Amer. Bull. 88, 1.

    Article  Google Scholar 

  • McFadden P.L. and Lowes F.J., 1981: The discrimination of mean directions drawn from Fisher distributions.Geophys. J. R. Astron. Soc. 67, 19–33.

    Google Scholar 

  • Nowaczyk N.R., Frederichs T.W., Eisenhauer A., and Gard G., 1994: Magnetostratigraphic data from late Quaternary sediments from the Yermak Plateau, Arctic Ocean: evidence for four geomagnetic polarity events within the last 170 Ka of the Brunhes Chron.Geophys. J. Int. 117, 453–471.

    Google Scholar 

  • Renne P., Walter R.C., Verosub K., Sweitzer M. and Aronson J., 1992: Magnetostratigraphy and40Ar/39Ar dating of the Hadar Formation, Ethiopia: GPTS calibration within the Gauss chron.EOS Trans. AGU, V32A-3, Fall Meeting Suppl., Poster, 628.

  • Renne P., Walter R.C., Verosub K., Sweitzer M. and Aronson J., 1993: New data from Hadar (Ethiopia) support orbitally tuned time scale to 3.3 Ma.Geophys. Res. Lett. 20, 1067–1070.

    Google Scholar 

  • Rochette P., Fillon G., Mattéi J.L. and Dekkers M.J., 1990: Magnetic transition at 30–34 Kelvin in pyrrhotite: insight into a widespread occurrence of this mineral in rocks.Earth Planet. Sci. Lett. 98, 319–328.

    Google Scholar 

  • Schmitt T.J. and Nairn A.E.M., 1984: Interpretations of the magnetostratigraphy of the Hadar hominid site, Ethiopia.Nature 390, 704–706.

    Google Scholar 

  • Shackleton N.J., Berger A. and Peltier W.R., 1990: An alternative astronomical calibration of the lower Pleistocene timescale based on ODP Site 677. Trans. Roy. Soc. Edinburgh, Earth Sci., 81, 251–261.

    Google Scholar 

  • Stacey F.D. and Banerjee S.K., 1974:The physical principles of rock magnetism. Elsevier, Amsterdam, 195 pp.

    Google Scholar 

  • Taieb M., 1974:Evolution quaternaire du bassin de l'Awash (Rift éthiopien et Afar), Thèse Doctorat d'Etat (Sciences naturelles) Université Paris 6 (FR). 2 volumes, 391p (in French).

  • Taieb M., Johanson D.C, Coppens Y. and Aronson J.L., 1976: Geological and paleontological background of Hadar hominid site, Afar, Ethiopia.Nature 260, 289–293.

    Article  Google Scholar 

  • Taieb M., and Tiercelin J.J., 1979: Sédimentation pliocène et paléoenvironnement de rift: exemple de la formation à hominidés d'Hadar (Afar, Ethiopie).Bull. Soc. Géol. Fr. 21, 243–253 (in French).

    Google Scholar 

  • Thellier E. and Thellier O., 1959: Sur l'intensité du champ magnétique terrestre dans le passée historique et géologique.Ann. Géophys. Paris 15, 285–376 (in French).

    Google Scholar 

  • Tiercelin J.J., 1986: The Pliocene Hadar Formation, Afar depression of Ethiopia. In: Sedimentation in the African Rifts. ed. FROSTICK L.E. et al (Eds.) pp:221–240.

  • Walter R.C., 1981:The volcanic history of the Hadar Early Man site and the surrounding Afar region of Ethiopia. Ph.D. Thesis, Case Western Reserve Univ., pp:426.

  • Walter R.C. and Aronson J.L., 1982: Revisions of K-Ar ages for the Hadar hominid site (Ethiopia).,Nature 296, 122–127.

    Article  Google Scholar 

  • Walter R.C. and Aronson J.L., 1993: Age and source of the Sidi Hakoma tuff, Hadar formation, Ethiopia.J. Human Evolution 25, 229–240.

    Google Scholar 

  • Walter, R.C., 1994: Age of Lucy and the first family: single-crystal40Ar/39Ar dating of the Denen Dora and lower Kada Hadar members of the hadar formation, Ethiopia.Geology 22, 6–10.

    Article  Google Scholar 

  • Zijderveld J.D.A., 1967: AC demagnetization of rocks: Analysis of results, In: D.W. Collinson, K.M. Creer and S.K. Runcorn (eds.),Methods in Paleomagnetism. Elsevier, Amsterdam, pp. 254–286.

    Google Scholar 

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  1. Laboratoire de Géologie du Quaternaire CEREGE, BP 80, 13545, Aix-en-Provence, Cedex 4, France

    Endale Tamrat, Nicolas Thouveny & Maurice Taieb

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  1. Endale Tamrat
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  2. Nicolas Thouveny
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  3. Maurice Taieb
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Tamrat, E., Thouveny, N. & Taieb, M. Magnetostratigraphy of the lower member of the hadar formation (Ethiopia): Evidence for a short normal event in the mammoth subchron. Stud Geophys Geod 40, 313–335 (1996). https://doi.org/10.1007/BF02300746

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  • DOI: https://doi.org/10.1007/BF02300746

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