Tamrat E., Thouveny Nicolas, Taieb M., Brugal J.P. (2014). Magnetostratigraphic study of the Melka Kunture archaeological site (Ethiopia) and its chronological implications. Quaternary International, 343, p. 5-16. ISSN 1040-6182.
Titre du document
Magnetostratigraphic study of the Melka Kunture archaeological site (Ethiopia) and its chronological implications
Tamrat E., Thouveny Nicolas, Taieb M., Brugal J.P.
Source
Quaternary International, 2014,
343, p. 5-16 ISSN 1040-6182
A magnetostratigraphy is established for the Melka Kunture archaeological site of Ethiopia, whose chronological setting needed improvement. The magnetostratigraphy is constructed from four distinct stratigraphic sections, Garba-IV (5 sites), Gombore-I (21 sites), Gombore-II (8 sites), and Simbiro (13 sites). Natural remanent magnetizations (NRM) were measured and analyzed over a total of 214 specimens to isolate the characteristic components of magnetization and determine magnetic polarities. Two magnetization components were isolated in every sample analyzed: (i) a low-temperature (low coercivity) secondary normal component and (ii) a high-temperature characteristic component of normal or reversed polarity and allows to identify five magnetozones (N1-R1-N2-R2-N3). Rock magnetic analysis attests that the magnetization is carried by magnetite or titanomagnetite within the range of pseudo-single domain grain sizes. Anisotropy of magnetic susceptibility (AMS) supports a sedimentary origin of the magnetic remanence. Based on recent Ar-40/Ar-39 geochronological dating of the site, faunal constraints and a magnetostratigraphic pattern, the sequence is correlated to the time between the early Matuyama chron (< 1.80 Ma) and early Brunhes chron (similar to 0.709 Ma) of the geomagnetic polarity time scale (GPTS). Completing recent Ar-40/Ar-39 age series, the magnetostratigraphy study presented here allows computation of interpolated ages for various faunal and artifact findings at Melka Kunture and similar fossiliferous deposits in the region.
