Stratigraphy and sedimentology of the Hadar Formation Afar, Ethiopia

Yemane, Tesfaye

doi:10.31274/rtd-180817-4964

Cited by 4 publications

(8 citation statements)

References 43 publications

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“…This explanation is an extension of Kalb et al's (1982) proposal that the Hadar Formation generally reflects a northeastwards migration of the Awash deposystem from the Middle Awash region during the Pliocene. Such a translation would have a similar effect as described by Yemane (1997), increasing the gradient between the western margin and the depocenter, and could have occurred with or without coeval uplift along the Ethiopian Escarpment. This interpretation fits the volcano-tectonic model of Lahitte et al (2003) which documents the northward migration of central Afar volcanism between 3 and 1 Ma, linked to the northward propagation of the Gulf of Aden Ridge.…”

Section: Cyclicity In the Hadar Sedimentary Recordmentioning

confidence: 73%

“…The upper Sidi Hakoma and lower Denen Dora lacustrine sequence, documenting the most persistent lake phase at Hadar, has been thought to be the result of tectonic factors (Voudra et al, 1994;Yemane, 1997). However, when viewed in the global climatic context, this lacustrine stage roughly coincides with the most stable period in both the oxygen isotope and terrigenous sediment flux records from marine cores during the Hadar sequence (Fig.…”

Section: The Influence Of Eccentricity-modulated "Variability Packets"mentioning

confidence: 84%

“…This disconformity marks a dramatic shift in facies character, stratigraphie completeness, and accumulation rates (Voudra et al, 1996;Yemane, 1997). Sediments below the disconformity have yielded numerous specimens of Australopithecus afarensis, while the upper Kada Hadar Member has yielded material attributed to Homo aff.…”

Section: Cyclicity In the Hadar Sedimentary Recordmentioning

confidence: 99%

“…Additionally, in combination with the global climatic context discussed below, we believe this evidence does not support the suggestion that the cyclicity in depositional environments at Hadar was controlled by rapid periodic basin subsidence resulting from displacement along major normal faults bounding the Ethiopian Rift (cf. Voudra et al, 1994;Yemane, 1997). The disconformity at Hadar may represent some 200,000 years, from ca.…”

Section: Cyclicity In the Hadar Sedimentary Recordmentioning

confidence: 99%

“…The thickness of post-disconformity sediments thins in a general west to east direction across the Gona, Hadar, and Middle Ledi regions. Yemane (1997) attributed the cobble conglomerates to braided-stream alluvial fan deposits resulting from western margin uplift, while Quade et al (2004) attributed them to deposition by the ancestral Awash River associated with a period of major erosion following the drying of the sub-disconformity lake. Recent work by Wynn et al (2006) has suggested that deposition in the Hadar Basin ceased after 2.9 Ma and that the Hadar Formation strata were uplifted from a depositional position by normal faults.…”

Section: Cyclicity In the Hadar Sedimentary Recordmentioning

confidence: 99%

See 4 more Smart Citations

Connecting local environmental sequences to global climate patterns: evidence from the hominin-bearing Hadar Formation, Ethiopia

Campisano

Feibel

2007

Journal of Human Evolution

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Section: Cyclicity In the Hadar Sedimentary Recordmentioning

confidence: 73%

Section: The Influence Of Eccentricity-modulated "Variability Packets"mentioning

confidence: 84%

Section: Cyclicity In the Hadar Sedimentary Recordmentioning

confidence: 99%

Section: Cyclicity In the Hadar Sedimentary Recordmentioning

confidence: 99%

Section: Cyclicity In the Hadar Sedimentary Recordmentioning

confidence: 99%

See 3 more Smart Citations

Connecting local environmental sequences to global climate patterns: evidence from the hominin-bearing Hadar Formation, Ethiopia

Campisano

Feibel

2007

Journal of Human Evolution

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“Lucy” redux: A review of research on Australopithecus afarensis

Kimbel

Delezene

2009

American J Phys Anthropol

211

140

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In the 1970s, mid-Pliocene hominin fossils were found at the sites of Hadar in Ethiopia and Laetoli in Tanzania. These samples constituted the first substantial evidence for hominins older than 3.0 Ma and were notable for some remarkable discoveries, such as the ''Lucy'' partial skeleton and the abundant remains from the A.L. 333 locality at Hadar and the hominin footprint trail at Laetoli. The Hadar and Laetoli fossils were ultimately assigned to the novel hominin species Australopithecus afarensis, which at the time was the most plesiomorphic and geologically ancient hominin taxon. The discovery and naming of A. afarensis coincided with important developments in theory and methodology in paleoanthropology; in addition, important fossil and genetic discoveries were changing expectations about hominin divergence dates from extant African apes. This coincidence of events ensured that A. afarensis figured prominently in the last 30 years of paleoanthropological research. Here, the 301 year history of discovery, analysis, and interpretation of A. afarensis and its contexts are summarized and synthesized. Research on A. afarensis continues and subject areas in which further investigation is needed to resolve ongoing debates regarding the paleobiol- Just over three decades ago, the east African early hominin species Australopithecus afarensis was recognized as the oldest, most apelike human ancestor. Although specimens now attributed to the species had resided in fossil collections since the 1930s, the bulk of the sample was amassed during field work in the 1970s at two sites, Hadar, Ethiopia, and Laetoli, Tanzania. Today, the species' hypodigm numbers more than 400 specimens collected from a half-dozen sites, most of which are still actively being worked (Table 1). Refinements in radioisotopic dating have established the species' first and last known appearances at 3.7 and 3.0 Ma, respectively. At the time of their discovery, these specimens constituted the first informative sample of hominin fossils older than 3.0 Ma.Studies on subjects ranging from the rise of striding bipedal locomotion to the origin of the uniquely human pattern of growth and development to the evolution of hominin dietary adaptations have drawn heavily on data from the remains of A. afarensis. Taxonomic and phylogenetic research, which experienced a major renaissance in paleoanthropology beginning around the time when A. afarensis was discovered, has benefited from the extensive baseline data on fossil hominin skeletal and dental variation residing in the Hadar site-sample. Some of the research topics that focus on A. afarensis-the extent to which terrestrial bipedality was the committed form of locomotion, the degree of sexual dimorphism in body size and implications for social behavior, and the ''shape'' of the phylogenetic tree prior to the emergence of the Homo and robust australopith lineages, to name just three prominent examples-are still actively debated today, which merely drives home the message that finding solutions to scien...

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