Tephrostratigraphy of Northern Tanzania
Leina assisting with fieldwork at Olduvai Gorge, Tanzania
Since 1999, Lindsay McHenry has been researching the tephrostratigraphy of Olduvai Gorge, Tanzania. Olduvai Gorge is famous for its exquisite record of hominin stone tools and paleontological materials (including hominins!), all preserved in a stratigraphic succession including many tuffs derived from the nearby Ngorongoro Volcanic Highlands. These tuffs serve as a great “tephrostratigraphic framework” for the area, allowing paleoanthropologists to correlate stratigraphic intervals of interest across the basin… that is, as long as those tuffs are properly identified! The high degree of alteration (from the saline-alkaline lake and associated fluids) makes this tough, since the volcanic glass favored by tephrostratigraphers is not preserved. McHenry and her team have instead used phenocryst compositions to develop this local framework.
This work also extends to nearby Laetoli, another paleoanthropological sites (with its famous Pliocene homin trackway, preserved in tephra!), the likely source volcanoes in the Ngorongoro Volcanic Highlands, and the Humbu and Moinik Formations of the Lake Natron basin to the north.
Related papers:
McHenry, L.J., Stanistreet, I.G., Stollhofen, H., Njau, J.K., Schick, K., Toth, N. 2020. Tuff fingerprinting and correlations between OGCP cores and outcrops for Pre-Bed I and Bed I/II at Olduvai Gorge, Tanzania. Palaeogeography Palaeoclimatology Palaeoecology 548:109630. doi.org/10.1016/j.palaeo.2020.109630
Zaitsev, A.N., McHenry, L.J., Savchenok, A.I., Strekopytov, S., Spratt, J., Humphreys-Williams, E., Sharygin, V.V., Bogomolov, E.S., Chakhmouradian, E.R, Zaitseva, O.A., Arzamastsev, A.A., Reguir, E.P., Leach, L., Leach, M., Mwankunda, J., 2019. Stratigraphy, mineralogy and geochemistry of the Upper Laetolil Tuffs including a new Tuff 7 site with footprints of Australopithecus afarensis, Laetoli, Tanzania. Journal of African Earth Sciences 158: 103561
McHenry, L.J., Stanistreet, I.G., 2018. Tephrochronology of Bed II, Olduvai Gorge, Tanzania, and placement of the Oldowan–Acheulean transition. Journal of Human Evolution 120: 7-18. DOI: 10.1016/j.jhevol.2017.12.006
Stainstreet, I.G., McHenry, L.J., Stollhofen, H., de la Torre, I., 2018. Bed II Sequence Stratigraphic context of EF-HR and HWK EE archaeological sites, and the Oldowan/Acheulean succession at Olduvai Gorge, Tanzania. Journal of Human Evolution 120: 19-31. DOI: 10.1016/j.jhevol.2018.01.005
McHenry, L.J., Njau, J.K., de la Torre, I., Pante, M.C., 2016. Geochemical “fingerprints” for Olduvai Gorge Bed II tuffs and implications for the Oldowan–Acheulean transition. Quaternary Research 85: 147-158. 10.1016/j.yqres.2015.10.005
Habermann, J.M., McHenry, L.J., Stollhofen, H., Tolosado-Delgado, R., Stanistreet, I.G., Deino, A.L., 2016. Discrimination, correlation, and provenance of Bed I tephrostratigraphic markers, Olduvai Gorge, Tanzania, based on multivariate analyses of phenocryst compositions. Sedimentary Geology 339: 115-133. Doi: 10.1016/j.sedgeo.2016.03.026
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: 235-247. doi: 10.1016/j.yqres.2013.05.006
McHenry, L.J., 2012. A revised stratigraphic framework for Olduvai Gorge Bed I based on tuff geochemistry. Journal of Human Evolution 63: 284-299. Doi: 10.1016/j.jhevol.2011.04.010
McHenry, L.J., Luque, L., Gómez, J.A., Diez-Martín, F., 2011. Promise and pitfalls for characterizing and correlating the zeolitically altered tephra of the Pleistocene Peninj Group, Tanzania. Quaternary Research 75: 708-720. doi:10.1016/j.yqres.2010.11.008
McHenry, L.J., 2011. Geochemistry and mineralogy of Laetoli area tuffs: Lower Laetolil through Naibadad Beds. In: Harrison, T. (Ed.) Paleontology and Geology of Laetoli, Tanzania: Human Evolution in Context. Volume 1: Geology, Geochronology, Paleoecology and Paleoenvironment. Springer series Vertebrate Paleobiology and Paleoanthropology. 121-141. doi:10.1007/978-90-481-9956-3_6
McHenry, L.J., 2010. Element distribution between coexisting authigenic mineral phases in argillic and zeolitic altered tephra, Olduvai Gorge, Tanzania. Clays and Clay Minerals 58(5): 627-643. doi: 10.1346/CCMN.2010.0580504
McHenry, L.J., 2009. Element mobility during zeolitic and argillic alteration of volcanic ash in a closed-basin lacustrine environment: Case study Olduvai Gorge, Tanzania. Chemical Geology 265: 540-552. doi:10.1016/j.chemgeo.2009.05.019
Mollel. G.F., Swisher, C.C. III, McHenry, L.J., Feigenson, M.D., Carr, M.J., 2009. Petrogenesis of basalt-trachyte lavas from Olmoti Crater, Tanzania. Journal of African Earth Sciences 54: 127-143. doi: 10.1016/j.jafrearsci.2009.03.008
McHenry, L.J., Mollel, G.M., and Swisher, C.C. III, 2008. Compositional and textural correlations between Olduvai Gorge Bed I tephra and volcanic sources in the Ngorongoro Volcanic Highlands, Tanzania. Quaternary International 178: 306-319. doi:10.1016/j.quaint.2007.01.004
Stollhofen, H., Stanistreet, I.G., McHenry, L.J., Mollel, G.F., Blumenschine, R.J., Masao, F.T., 2008. Fingerprinting facies of the Tuff IF marker, catastrophe for early hominin palaeoecology, Olduvai Gorge, Tanzania. Palaeogeography, Palaeoclimatology, Palaeoecology. 259: 382-409. doi:10.1016/j.palaeo.2007.09.024
McHenry, L.J., 2005. Phenocryst composition as a tool for correlating fresh and altered tephra, Bed I, Olduvai Gorge, Tanzania. Stratigraphy 2(2):101-115.
Blumenschine, R.J., Peters, C.R., Masao, F.T., Clarke, R.J., Deino, A.L., Hay, R.L., Swisher, C.C., Stanistreet, I.G., Ashley, G.M., McHenry, L.J., Sikes, N.E., van der Merwe, N.J., Tactikos, J.C., Cushing, A.E., Deocampo, D.M., Njau, J.K., Ebert, J.I. 2003. Late Pliocene Homo and hominid land use from western Olduvai Gorge, Tanzania. Science, v. 299 p. 1217-1221.