Use of single-grain geochemistry of cryptic tuffs and volcaniclastic sandstones improves the tephrostratigraphic framework of Olduvai Gorge, Tanzania.

Mchenry LJ, Stollhofen H, Stanistreet IG (2013)

Publication Language: English

Publication Type: Journal article, Original article

Publication year: 2013

Journal

Quaternary Research Cambridge University Press

Publisher: Elsevier

Book Volume: 80

Pages Range: 235-249

DOI: 10.1016/j.yqres.2013.05.006

Abstract

Single-grain geochemical composition of volcaniclastic sandstones can be a potential tool to improve correlations of mixed pyroclastic/epiclastic deposits. To test this, trachytic tuffs of the paleoanthropologically important FLK, FLK N, and FLK NN sites of Pleistocene Olduvai Gorge Bed I (Tanzania) are used as an established tephrostratigraphic framework against which to test volcaniclastic sandstone correlations. Fluvio-lacustrine sandstones and tuff samples were collected from eight archeological trenches between Tuffs IB and ID across a 500-m transect, including Leakey's famous Zinjanthropus (FLK) and OH 7/OH 8 (FLK NN) sites. A previously unknown, thin, fine, mineralogically unique, black trachyandesitic fallout ash was discovered below Tuff IC. Compositions of individual augite, feldspar and titanomagnetite grains from sandstones between Tuffs IB and IC reveal some IB-equivalent material, and a new compositional assemblage distinct from the sandwiching marker tuffs. Mineral compositions of the "tripartite" volcaniclastic sandstone between Tuffs IC and ID are similar to ID. Volcaniclastic sandstone grain fingerprints further refine correlations between fluvio-lacustrine sections within the area, providing support for proposed high-resolution stratigraphic reconstruction of the Zinjanthropus and OH 7/OH 8 land surfaces. This method might be applied to other sections where pyroclastic particles are admixed but distinct tuffs are not preserved. © 2013 University of Washington.

Authors with CRIS profile

Harald Stollhofen Lehrstuhl für Geologie (Exogene Dynamik)

Related research project(s)

Plio-Pleistocene volcanism of Lower Bed I, Olduvai Gorge, Tanzania: transportation mechanisms, volcaniclastic sedimentation and ecological significance July 1, 2010 - July 30, 2013

Involved external institutions

The University of Liverpool GB United Kingdom (GB) University of Wisconsin - Madison US United States (USA) (US)

How to cite

APA:

Mchenry, L.J., Stollhofen, H., & Stanistreet, I.G. (2013). Use of single-grain geochemistry of cryptic tuffs and volcaniclastic sandstones improves the tephrostratigraphic framework of Olduvai Gorge, Tanzania. Quaternary Research, 80, 235-249. https://dx.doi.org/10.1016/j.yqres.2013.05.006

MLA:

Mchenry, Lindsay J., Harald Stollhofen, and Ian G. Stanistreet. "Use of single-grain geochemistry of cryptic tuffs and volcaniclastic sandstones improves the tephrostratigraphic framework of Olduvai Gorge, Tanzania." Quaternary Research 80 (2013): 235-249.

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