Lithostratigraphy of the Late Miocene to Early Pleistocene, hominid-bearing Galili Formation, Southern Afar Depression, Ethiopia

Abstract

The Horn of Africa is yields famous Miocene to Pleistocene fossil sites including hominid remains. The fossiliferous sediments were deposited in fluvio-deltaic to lacustrine environments. The basin development is mainly controlled by the tectonic development of the Afar Depression. The Galili research area represents a new fossil site in the southern Afar Depression, Ethiopia. The exposed sediments and volcanics have been organized in the 230 m thick Galili Formation that consists in ascending stratigraphic order of the Lasdanan, Dhidinley, Godiray, Lower and Upper Shabeley Laag, Dhagax and Caashacado Members. The individual members are defined by volcanic layers like basalts, ignimbrites and tuffs. Feldspars separated from several volcanic layers have been dated

Paleomagnetic constraints on stratigraphy and rift-related tectonics of Pliocene and Early Pleistocene volcano-sedimentary strata: the Mt. Galili hominid research area, Southern Afar Depression, Ethiopia

“…1) provided from Hujer et al (2015), four different samples (U11, 09/16A, 09/29, 09/32), albeit of different quality, seem to point towards a depostional age around 3.9 Ma. One sample is substantially younger (U51 at 2.35 Ma) and three samples are older (09/16 at~4.25 Ma, W78 at ~4.43 Ma and W133/2 at ~5.37 Ma).…”

“…According to Urbanek et al (2005) and Hujer et al (2015), the MGF represents a succession of fluvio-lacustrine sediments, comprising several horizons of volcanic layers, which are subdivided into six members (Figs. 2 and 8: a), each representing a sedimentary cycle and typically ending with strata recording volcanic activity.…”

“…1 and 7a). position ( ) of tuffs and ignimbrites used for absolute Ar/ Ar dating of feldspar minerals as presented in Hujer et al (2015), resultant absolute age data with their related sample number (Tab. 1) are indicated.…”

“…A composite lithologic profile of the MGF (Fig. 8: a, b, modified after Urbanek et al, 2005 andHujer et al, 2015), completed with absolute age data from tuff horizons ( Fig. 8: c; see Hujer et al, 2015), was the basis for our consideration relating to its magneto-stratigraphic correlation (Fig.…”

“…Absolute ( Ar/ Ar) age data obtained from volcanic tuff layers by Hujer et al (2015) serve as stratigraphic markers within the examined volcano-sedimentary sequence. Examination of numerous profiles from sedimentary sections (Hujer et al, 2015) and field observations of rift tectonic displacement features were used to determine the stratigraphic positions of the paleomagnetic sample sites. For the purpose of stratigraphic correlation with other regions of the MER, previous papers have been checked: Earlier…”