Petrology, Geochemistry and Age of Satiman, Lemagurut and Oldeani: Sources of the Volcanic Deposits of the Laetoli Area

  • Godwin F. MollelEmail author
  • Carl C. SwisherIII
  • Mark D. Feigenson
  • Michael J. Carr
Part of the Vertebrate Paleobiology and Paleoanthropology Series book series (VERT)


We report on the petrochemistry and geochronology of lavas from Satiman, Lemagurut and Oldeani volcanoes, as well as from isolated Ogol flows. Comparisons of their age and mineral compositions are made with those of the Laetolil Beds to confirm the sources for these latter volcaniclastic deposits. A comparison with other volcanic centers in the region and an attempt to constrain the depth at which melting occurs is also made. Lava compositions vary between centers, with Satiman composed of foidite and phonolite. Lemagurut ranges from basalt through benmorite, whereas Oldeani is basalt and trachyandesite, and Ogol is basaltic. The Sr-Nd isotopes of these lavas are characterized by relative unradiogenic Nd (143Nd/144Nd =0.512056 – 0.512610), but with radiogenic Sr (87Sr/86Sr = 0.70371 – 0.70609), suggesting a source explained by mixing between high-μ and enriched mantle reservoirs. These isotope ratios, together with trace elements patterns and ratios (e.g., Tb/Yb), indicate melting in the lithospheric mantle consistent with other studies in the region. 40Ar/39Ar dating indicates an age range for Satiman of 4.63 ± 0.05 to 4.02 ± 0.02 Ma, Lemagurut and Ogol from 2.40 ± 0.01 to 2.22 ± 0.10 Ma and Oldeani from 1.61 ± 0.01 to 1.52 ± 0.02 Ma. The age of Satiman and its silica undersaturated composition make it the likely source of the > 4.3 – 3.5 Ma Laetolil Beds. The age and composition of Naibadad Beds that overlie the Laetoli Beds are consistent with the composition and revised ages of 2.28 ± 0.02 – 2.04 ± 0.01 Ma for Ngorongoro. The Olpiro Beds, which are fine-grained and of phonolitic composition, may correlate best with the more distal Olmoti Crater.


40Ar/39Ar dating Petrology Geochemistry Ogol Tanzania 



We would like to thank the Tanzania Commission for Science and Technology and the Tanzania Antiquities Department for granting permission to conduct research at Laetoli, Olduvai, and Ngorongoro volcanic highlands. The Laetoli Project and Olduvai Landscape Paleoanthropology Project (OLAPP) provided field support. Terry Harrison and Gail Ashley provided plane tickets to the field, Robert Blumenschine and Fidelis Masao provided field gear, and Craig Feibel and Jerry Delaney provided support during data collection. Funding for this research was partly provided by the L.S.B. Leakey Foundation to Mollel, Sigma Xi, NSF (Harrison: BCS-0309513; Ashley: EAR 9903258; Swisher: BCS-0109027; Feibel: BCS-0218511) and the Department of Earth and Planetary Sciences, Rutgers University. Comments on an earlier version of this manuscript by anonymous reviewers were of great value.


  1. Adelsberger, K. A, Wirth, K. R., & Mabulla, A. Z. P. (2002). Provenance of middle stone age tools of the Laetoli archaeological site. Tanzania. Geological Society of America (GSA), Abstract with Programs 34, 110.Google Scholar
  2. Adelsberger, K. A., Wirth, K. R., Mabulla, A. Z. P., & Bowman, D. C. (2011). Geochemical and mineralogical characterization of middle stone age tools of Laetoli, Tanzania and comparisons with possible source materials. In T. Harrison (Ed.), Paleontology and geology of Laetoli: Human evolution in context (Geology, geochronology, paleoecology and paleoenvironment, vol. 1, pp. 143–165). Dordrecht: Springer.Google Scholar
  3. Bagdasaryan, G. P., Gerasimovskiy, V., Polyakov, A. I., & Gukasyan, R Kh. (1973). Age of volcanic rocks in the rift zones of East Africa. Geochemistry International, 10, 66–71.Google Scholar
  4. Bell, K., & Simonetti, A. (1996). Carbonatite magmatism and plume activity: Implications from the Nd, Pb and Sr isotope systematics of Oldoinyo Lengai. Journal of Petrology, 37, 1321–1339.CrossRefGoogle Scholar
  5. Bell, K., & Tilton, G. (2001). Nd, Pb and Sr isotopic compositions of East African carbonatites: Evidence for mantle mixing and plume inhomogeneity. Journal of Petrology, 42, 1927–1945.CrossRefGoogle Scholar
  6. Bevington, P. R. (1969). Data reduction and error analysis for physical sciences. New York: McGraw-Hill.Google Scholar
  7. Bizimis, M., Salters, V. J. M., & Dawson, B. D. (2003). The brevity of carbonatite source in the mantle: Evidence from Hf isotope. Contributions to Mineralogy and Petrology, 145, 281–300.CrossRefGoogle Scholar
  8. Bolge, L., Carr, M. J., Feigenson, M., & Alvarado, G. (2006). Geochemical stratigraphy and magmatic evolution at Arenal volcano, Costa Rica. Journal of Volcanology and Geothermal Research, 157, 34–48.CrossRefGoogle Scholar
  9. Cahen, L., Snelling, J. J., Delhal, J., & Vail, J. R. (1984). The geochronology and evolution of Africa. Oxford: Clarendon.Google Scholar
  10. Carr, M. J., Saginor, I., Alvarado, G. E., Bolge, L. L., Lindsay, F. N., Milidakis, K., Turrin, B., Feigenson, M. D., & Swisher, C. C., III. (2007). Element fluxes from the volcanic front of Nicaragua and Costa Rica. Geochemistry, Geophyics, Geosystems, 8, Q06001. doi: 10.1029/2006GC001396.Google Scholar
  11. Class, C., Altherr, R., Volker, F., Eberz, G., & McCulloch, M. (1994). Geochemistry of Pliocene to Quaternary alkali basalts from the Huri Hills, northern Kenya. Chemical Geology, 113, 1–22.CrossRefGoogle Scholar
  12. Cohen, R. S., O’Nions, R. K., & Dawson, J. B. (1984). Isotope geochemistry of xenoliths from East Africa: Implications for development of mantle reservoirs and the interaction. Earth and Planetary Science Letters, 68, 209–220.CrossRefGoogle Scholar
  13. Cox, A. (1969). Geomagnetic reversals. Science, 163, 237–245.CrossRefGoogle Scholar
  14. Cox, K. G., Bell, J. D., & Pankhurst, R. J. (1979). The interpretation of the igneous rocks. London: Allen and Unwin.CrossRefGoogle Scholar
  15. Curtis, G. H., & Hay, R. L. (1972). Further geological studies and potassium-argon dating at Olduvai Gorge and Ngorongoro Crater. In W. W. Bishop & J. A. Miller (Eds.), Calibration of hominoid evolution (pp. 289–301). Edinburgh: Scottish Academic.Google Scholar
  16. Davies, G. R., & MacDonald, R. (1987). Crustal influence in the petrogenesis of the naivasha basalt–comendite complex: Combined trace element and Sr–Nd–Pb isotope constraints. Journal of Petrology, 28, 1009–1031.CrossRefGoogle Scholar
  17. Dawson, J. B., Bowden, P., & Clark, G. C. (1968). Activity of the carbonatite volcano Oldoinyo Lengai, 1966. International Journal of Earth Sciences, 57, 865–879.Google Scholar
  18. Deino, A. L. (2011). 40Ar/39Ar dating of Laetoli, Tanzania. In T. Harrison (Ed.), Paleontology and geology of Laetoli: Human evolution in context (Geology, geochronology, paleoecology and paleoenvironment, vol. 1, pp. 77–97). Dordrecht: Springer.Google Scholar
  19. Deino, A. L., & McBrearty, S. (2002). 40Ar/39Ar dating of the Kapthurin Formation, Baringo, Kenya. Journal of Human Evolution, 42, 185–210.CrossRefGoogle Scholar
  20. Deniel, C., Vidal, P., Coulon, C., Vellutini, P., & Piguet, P. (1994). Temporal evolution of mantle sources during continental rifting: The volcanism of Djibouti (Afar). Journal of Geophysical Research, 99, 2853–2869.CrossRefGoogle Scholar
  21. Ditchfield, P., & Harrison, T. (2011). Sedimentology, lithostratigraphy and depositional history of the Laetoli area. In T. Harrison (Ed.), Paleontology and geology of Laetoli: Human evolution in context (Geology, geochronology, paleoecology, and paleoenvironment, vol. 1, pp. 47–76), Dordrecht: Springer.Google Scholar
  22. Drake, R., & Curtis, G. (1987). K-Ar geochronology of the Laetoli fossil localities. In M. D. Leakey & J. M. Harris (Eds.), Laetoli: A Pliocene site in northern Tanzania (pp. 48–52). Oxford: Clarendon.Google Scholar
  23. Furman, T. (2007). Geochemistry of East African rift basalts: An overview. Journal of African Earth Sciences, 48, vol. 1, pp.147–160.CrossRefGoogle Scholar
  24. Furman, T., Bryce, J., Karson, J., & Iotti, A. (2004). East African Rift System (EARS) plume structure: Insights from Quaternary mafic lavas from Turkana, Kenya. Journal of Petrology, 45, vol. 1, pp. 1069–1088.CrossRefGoogle Scholar
  25. Furman, T., Kaleta, K. M., Bryce, J. G., & Hanan, B. B. (2006). Tertiary mafic lavas of Turkana, Kenya: Constraints on the East African plume structure and the occurence of high-μ volcanism in Africa. Journal of Petrology, 47, 1221–1244.CrossRefGoogle Scholar
  26. Hannah, R. S., Vogel, T. A., Patino, L. C., Alvarado, G. E., Pérez, W., & Smith, D. R. (2002). Origin of silicic volcanic rocks in Central Costa Rica: A study of a chemically variable ash-flow sheet in the Tiribí Tuff. Bulletin of Volcanology, 64, 117–133.CrossRefGoogle Scholar
  27. Harrison, T., & Baker, E. (1997). Paleontology and biochronology of fossil localities in the Manonga Valley, Tanzania. In T. Harrison (Ed.), Neogene paleontology of the Manonga Valley, Tanzania (pp. 361–393). New York: Plenum Press.CrossRefGoogle Scholar
  28. Harrison, T., Verniers, J., Mbago, M. L., & Krigbaum, J. (1993). Stratigraphy and mammalian paleontology of Neogene sites in the Manonga valley, northern Tanzania. Discovery and Innovation, 5, 269–275.Google Scholar
  29. Hart, S. R., Hauri, E. H., Oschmann, L. A., & Whitehead, J. A. (1992). Mantle plumes and entrainment: Isotopic evidence. Science, 256, 517–520.CrossRefGoogle Scholar
  30. Hay, R. (1976). Geology of the Olduvai Gorge: A study of sedimentation in a semi-arid basin. Berkeley: University of California Press.Google Scholar
  31. Hay, R. L. (1987). Geology of the Laetoli area. In M. D. Leakey & J. M. Harris (Eds.), Laetoli: A Pliocene site in northern Tanzania (pp. 23–47). Oxford: Clarendon.Google Scholar
  32. Hofmann, A. W., Jochum, K. P., Seufert, M., & White, W. M. (1986). Nb and Pb in oceanic basalts: New constraints on mantle evolution. Earth and Planetary Science Letters, 79, 33–45.CrossRefGoogle Scholar
  33. Johnson, J. S., Gibson, S. A., Thompson, R. N., & Nowell, G. M. (2005). Volcanism in the Vitim volcanic field, Siberia: Geochemical evidence for a mantle plume beneath the Baikal rift zone. Journal of Petrology, 46, 1309–1344.CrossRefGoogle Scholar
  34. Jones, A. P., Smith, J. V., Hansen, E. C., & Dawson, B. D. (1983). Metamorphism, partial melting and K-metasomatism of garnet-scapolite-kyanite granulite xenoliths from Lashaine, Tanzania. Journal of Geology, 91, 143–165.CrossRefGoogle Scholar
  35. Kalt, A., Hegner, E., & Satir, M. (1997). Nd, Sr, and Pb isotopic evidence for diverse lithospheric mantle sources of East African rift carbonatites. Tectonics, 278, 31–45.Google Scholar
  36. Keller, J., Zaitsev, A. N., & Wiedenmann, D. (2006). Primary magmas at Oldoinyo Lengai: The role of olivine melilitites. Lithos, 91, 150–172.CrossRefGoogle Scholar
  37. Key, R., Charsley, T., Hackman, B., Wilkinson, A., & Rundle, C. (1989). Superimposed upper Proterozoic collision-controlled orogenies in the Mozambican orogenic belt of Kenya. Precambrian Research, 44, 197–225.CrossRefGoogle Scholar
  38. Klaudius, J., & Keller, J. (2006). Peralkaline silicate lavas at Oldoinyo Lengai, Tanzania. Lithos, 91, 173–190.CrossRefGoogle Scholar
  39. Lee, C.-T., & Rudnick, R. L. (1999). Compositionally stratified cratonic lithosphere: Petrology and geochemistry of peridotite xenoliths from the Labait tuff cone, Tanzania. In J. J. Gurney, J. L. Gurney, M. D. Pascoe, & S. H. Richardson (Eds.), The Nixon Volume. Proceedings of the seventh international kimberlite conference (pp. 503–521). Cape Town: University of Cape Town.Google Scholar
  40. Mandeville, C. W., Webster, J. D., Rutherford, M. J., Taylor, B. E., Timbal, A., & Faure, K. (2002). Determination of molar absorptivities for infrared absorption bands of H2O in andesitic glasses. American Mineralogist, 87, 813–821.Google Scholar
  41. Manega, P. C. (1993). Geochronology, geochemistry and isotopic study of the Plio- Pleistocene hominid sites and the Ngorongoro volcanic highlands in northern Tanzania. Ph.D. dissertation. University of Colorado, Boulder.Google Scholar
  42. McDougall, I., & Harrison, M. (1999). Geochronology and thermochronology by the 40 Ar/ 39 Ar method. New York: Oxford University Press.Google Scholar
  43. McHenry, L. J. (2004). Characterization and correlation of altered Plio-Pleistocene tephra using a “multiple technique” approach: Case study at Olduvai Gorge Tanzania. Ph.D. dissertation, Rutgers University, New Brunswick.Google Scholar
  44. McHenry, L. J., Mollel, G. M., & 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.CrossRefGoogle Scholar
  45. Mertz, D. F., Weinrich, A. J., Sharp, W. D., & Renne, P. R. (2001). Alkaline intrusions in a near-trench setting, Franciscan complex, California: Constrains from geochemistry, petrology and 40Ar/39Ar chronology. American Journal of Science, 301, 877–911.CrossRefGoogle Scholar
  46. Mollel, G. (2002). Petrology and geochemistry of the southeastern Ngorongoro Volcanic Highland (NVH); and contribution to “sourcing” of stone tools at Olduvai Gorge, Tanzania. Masters thesis, Rutgers University, Piscataway.Google Scholar
  47. Mollel, G. F. (2007). Petrochemistry and geochronology of the Ngorongoro Volcanic Highland Complex (NVHC) and its relationship to Laetoli and Olduvai Gorge, Tanzania. Ph.D. dissertation, Rutgers University.Google Scholar
  48. Mollel, G. F., Swisher, C. C., Feigenson, M. D., & Carr, M. J. (2008). Geochemical evolution of lavas from Ngorongoro Caldera, Tanzania: Implications for crust-magma interaction. Earth and Planetary Science Letters, 271, 337–347.CrossRefGoogle Scholar
  49. Mollel, G. F., Swisher, C. C., 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.CrossRefGoogle Scholar
  50. Möller, A., Mezger, K., & Schenk, V. (1998). Crustal age domains and the evolution of continental crust in Mozambique belt of Tanzania: Combined Sm–Nd, Rb–Sr, and Pb–Pb isotopic evidence. Journal of Petrology, 39, 749–783.CrossRefGoogle Scholar
  51. Mutakyahwa, M. (1997). Mineralogy of the Wembere-Manonga formation, Manonga Valley, Tanzania, and possible provenance of the sediments. In T. Harrison (Ed.), Neogene paleontology of the Manonga Valley. Tanzania (vol. 1, pp. 67–78). New York: Plenum.CrossRefGoogle Scholar
  52. Ndessokia, P. (1990). The mammalian fauna and archaeology of the Ndolanya and Olpiro Beds, Laetoli, Tanzania. Ph.D. dissertation. University of California, Berkeley.Google Scholar
  53. Nielsen, T. F. D., & Veksler, I. V. (2002). Is natrocarbonatite a cognate fluid condensate? Contributions to Mineralogy and Petrology, 142, 425–435.CrossRefGoogle Scholar
  54. Nyblade, A. A., Owens, J. T., Gurrola, H., Retsema, J., & Langston, C. A. (2000). Seismic evidence for a deep upper mantle thermal anomaly beneath East Africa. Geology, 28, 599–602.CrossRefGoogle Scholar
  55. Paslick, C., & Halliday, A. N. (1996). Indirect crustal contamination: Evidence from isotopic and chemical disequilibria in minerals from alkali basalts and nephelines from northern Tanzania. Contributions to Mineralogy and Petrology, 125, 277–292.CrossRefGoogle Scholar
  56. Paslick, C., Halliday, A. N., James, D., & Dawson, J. B. (1995). Enrichment of continental lithosphere by OIB melts: Isotopic evidence from the volcanic province of northern Tanzania. Earth and Planetary Science Letters, 130, 109–126.CrossRefGoogle Scholar
  57. Pickering, R. (1964). Endulen. Quarter degree sheet, 52. Geological Survey of Tanzania.Google Scholar
  58. Renne, P., Swisher, C., III, Deino, A., Kamer, D., Owens, T., & DePaolo, D. (1998). Intercalibration of standards, absolute ages, and uncertainties in 40Ar/39Ar dating. Chemical Geology, 145, 117–152.CrossRefGoogle Scholar
  59. Rogers, W. M., James, D., Kelley, S. P., & De Mulder, M. (1998). The generation of potassic lavas from eastern Virunga province, Rwanda. Journal of Petrology, 39, 1223–1247.CrossRefGoogle Scholar
  60. Späth, A., Le Roex, A., & Opiyo-Akech, N. (2001). Plume-lithosphere interaction and the origin of continental rift-related alkaline volcanism-the Chyulu Hills volcanic province, southern Kenya. Journal of Petrology, 42, 765–787.CrossRefGoogle Scholar
  61. Sun, S., & McDonough, W. F. (1989). Chemical and isotopic systematics of oceanic basalts: Implications for mantle composition and processes. In A. D. Sounders & M. J. Norry (Eds.), Magmatism in the ocean basins (Vol. 42, pp. 313–345). London: Geological Society Special Publication.Google Scholar
  62. Trua, T., Deniel, C., & Mazzuoli, R. (1999). Crustal control in the genesis of Plio-quaternary biomodal magmatism of the Main Ethiopian Rift (MER): Geochemical and isotopic (Sr, Nd, Pb) evidence. Chemical Geology, 155, 201–231.CrossRefGoogle Scholar
  63. Turrin, B. D., Muffler, L. J. P., Clynne, M. A., & Champion, D. E. (2007). Robust 24 ± 6 ka 40Ar/39Ar age of a low-potassium tholeiitic basalt in the Lassen region of NE California. Quaternary Research, 68, 96–110.CrossRefGoogle Scholar
  64. Verniers, J. (1997). Detailed stratigraphy of the Neogene sediments at Tinde and other localities in the central Manonga basin. In T. Harrison (Ed.), Neogene paleontology of the Manonga Valley, Tanzania (pp. 67–78). New York: Plenum.Google Scholar
  65. Vukadinovic, D. (1994). High-field-strength elements in Javanese arc basalts and chemical layering in the mantle wedge. Journal of Mineralogy and Petrology, 55, 293–308.CrossRefGoogle Scholar
  66. Weeraratne, D. S., Forsyth, D. W., Fischer, K. M., & Nyblade, A. A. (2003). Evidence for an upper mantle plume beneath the Tanzania craton from rayleigh wave tomography. Journal of Geophysical Research, 108(B9), 2427.CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media B.V. 2011

Authors and Affiliations

  • Godwin F. Mollel
    • 1
    • 2
    Email author
  • Carl C. SwisherIII
    • 1
  • Mark D. Feigenson
    • 1
  • Michael J. Carr
    • 1
  1. 1.Department of Earth and Planetary SciencesRutgers UniversityPiscatawayUSA
  2. 2.Department of Earth and Atmospheric SciencesUniversity of AlbertaEdmontonCanada

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