Bulletin of Volcanology

, 71:301 | Cite as

Emplacement and inflation of natrocarbonatitic lava flows during the March–April 2006 eruption of Oldoinyo Lengai, Tanzania

  • Hannes B. Mattsson
  • Jaana Vuorinen
Research Article


The most voluminous eruption of natrocarbonatite lava hitherto recorded on Earth occurred at Oldoinyo Lengai in March–April 2006. The lava flows produced in this eruption range from blocky 'a'a type to smooth-surfaced inflated pahoehoe. We measured lava inflation features (i.e. one tumulus and three pressure ridges) that formed in the various pahoehoe flows emplaced in this event. The inflation features within the main crater of Oldoinyo Lengai are relatively small-scale, measuring 1-5 m in width, 2.5–24.4 m in length and with inflation clefts less than 0.4 m deep. Their small sizes are in contrast to a tumulus that formed on the northwestern slope of the volcano (situated ~1140 m below the crater floor). The tumulus is roughly circular, measures 17.5 × 16.0 m, and is cut by a 4.4 m deep axial inflation cleft exposing two separate flow units. We measured the elastic properties (i.e. shear- and bulk moduli) of natrocarbonatitic crust and find that these are similar to those reported for basaltic crust, and that there is no direct correlation between magmastatic head and pressure required to form tumuli. All inflated flows in the 2006 event were confined by lateral barriers (main crater, erosional channel or erosional gully) suggesting that the two most important factors for endogenous growth in natrocarbonatitic lava flows are (1) lateral barriers that prevent widening of the flow, and (2) influx of new material beneath the viscoelastic and brittle crust.


Natrocarbonatite Oldoinyo Lengai Inflation Pahoehoe Tumuli Elastic moduli 



The fieldwork to conduct the present study was funded by research/travel grants from the Swedish Research Council (VR), Nordic Volcanological Center (NORDVULK), and the Royal Swedish Academy of Sciences (KVA). Fabio Ferri and Luigi Burlini assisted with the analyses of mechanical properties of natrocarbonatitic lavas at ETH Zürich. Matthieu Kervyn, Jurgis Klaudius, Luca Caricchi, Alex Teague and Peter Ulmer are gratefully acknowledged for many interesting discussions on various aspects of Lengai volcanism. HBM would also like to thank Melanie Finn and Matthew Aeberhard for their generous hospitality during the 2007 visit to the Lake Natron area. Finally, we would also like to thank Andreas Jallas (for excellent dry-preparation of thin sections). Insightful reviews by Laszlo Keszthelyi and an anonymous reviewer are gratefully appreciated.


  1. Appelgate B, Embley RW (1992) Submarine tumuli and inflated tube-fed lava flows on Axial Volcano, Juan de Fuca Ridge. Bull Volcanol 54:447–458CrossRefGoogle Scholar
  2. Birch F (1961) The velocity of compressional waves in rocks to 10 kbar, Part 2. J Geophys Res 66:2199–2224CrossRefGoogle Scholar
  3. Burlini L, Arbaret L, Zeilinger G, Burg J-P (2005) High-temperature and pressure seismic properties of a lower crustal prograde shear zone from the Kohistan Arc, Pakistan. In: Bruhn D, Burlini L (eds) High-Strain Zones: Structure and Physical Properties. Geol Soc Lond Spec Publ 245:187–202CrossRefGoogle Scholar
  4. Cashman KV, Kauahikaua JP (1997) Reevaluation of vesicle distributions in basaltic lava flows. Geology 25:419–422CrossRefGoogle Scholar
  5. Chitwood LA (1994) Inflated basaltic lava: examples of processes and landforms from central and Southeast Oregon. Oregon Geol 56:11–20Google Scholar
  6. Church AA, Jones AJ (1995) Silicate-carbonate immiscibility at Oldoinyo Lengai. J Petrol 36:869–889Google Scholar
  7. Dawson JB, Pinkerton H, Norton GE, Pyle D (1990) Physiochemical properties of alkali carbonatite lavas: data from the 1988 eruption of Oldoinyo Lengai, Tanzania. Geology 18:260–263CrossRefGoogle Scholar
  8. Dawson JB, Pinkerton H, Pyle DM, Nyamweru C (1994) June 1993 eruption of Oldoinyo Lengai, Tanzania; exceptionally viscous and large carbonatite lava flows and evidence for coexisting silicate and carbonate magmas. Geology 22:799–802CrossRefGoogle Scholar
  9. Duncan AM, Guest JE, Stofan ER, Anderson SW, Pinkerton H, Calvari S (2004) Development of tumuli in the medial portion of the 1983 aa flow-field, Mount Etna, Sicily. J Volcanol Geotherm Res 132:173–187CrossRefGoogle Scholar
  10. Duraiswami RA, Bondre NR, Dole G, Phadnis VM, Kale VS (2001) Tumuli and associated features from western Deccan Volcanic Province, India. Bull Volcanol 63:435–442CrossRefGoogle Scholar
  11. Ferri F, Burlini L, Cesare B, Sassi R (2007) Seismic properties of lower crustal xenoliths from El Hoyazo (SE Spain): experimental evidence up to partial melting. Earth Plan Sci Lett 253:239–253CrossRefGoogle Scholar
  12. Fornari DJ, Malahoff A, Heezen BC (1978) Volcanic structure of the crest of the Puna Ridge, Hawaii: geophysical implications of submarine volcanic chain. Geol Soc Am Bull 89:605–616CrossRefGoogle Scholar
  13. Guilbaud M-N, Blake S, Self S, Thordarson T, Keszthelyi L (2006) Internal textures and cooling histories of rubbly pahoehoe lavas. A George P.L. Walker symposium on Advances in Volcanology, IAVCEI, Reykholt, Iceland, Abstract volume p. 14Google Scholar
  14. Gudmundsson A (2004) Effects of Young’s modulus on fault displacement. Comptes Rendus—Geoscience 336:85–92CrossRefGoogle Scholar
  15. Gudmundsson A, Philipp SL (2006) How local stress fields prevent volcanic eruptions. J Volcanol Geotherm Res 158:257–268CrossRefGoogle Scholar
  16. Hon K, Kauhikaua J, Denlinger R, MacKay K (1994) Emplacement and inflation of pahoehoe sheet flows: Observations and measurements of active lava flows on Kilauea Volcano, Hawaii. Geol Soc Am Bull 106:351–370CrossRefGoogle Scholar
  17. Huppert HE, Sparks RSJ (1985) Komatiites I: emplacement and flow. J Petrol 26:694–725Google Scholar
  18. Jarvis RA (1995) On the cross-sectional geometry of thermal erosion channels formed by turbulent lava flows. J Geophys Res 100:10127–10140CrossRefGoogle Scholar
  19. Keller J, Krafft M (1990) Effusive natrocarbonatite activity of Oldoinyo Lengai, June 1988. Bull Volcanol 52:629–645CrossRefGoogle Scholar
  20. Kervyn M, Ernst GGJ, Klaudius J, Keller J, Kervyn F, Mattsson HB, Belton F, Mbede E, Jacobs P (2008) Voluminous lava flows at Oldoinyo Lengai in 2006: Chronology of events and insights into the shallow magmatic system. Bull Volcanol DOI  10.1007/s00445-007-0190-x
  21. Klaudius J, Keller J (2006) Peralkaline silicate lavas at Oldoinyo Lengai, Tanzania. Lithos 91:173–190CrossRefGoogle Scholar
  22. Mattsson HB, Höskuldsson Á (2005) Eruption reconstruction, formation of flow-lobe tumuli and eruption duration in the 5900 BP Helgafell lava field (Heimaey), south Iceland. J Volcanol Geotherm Res 147:157–172CrossRefGoogle Scholar
  23. Norton G, Pinkerton H (1997) Rheological properties of natrocarbonatite lavas from Oldoinyo Lengai, Tanzania. European J Min 9:351–364Google Scholar
  24. Oddsson B (1984) Geology and geotechnical behaviour of the young volcanic rocks of Iceland with emphasis on the effects of petrography. PhD Thesis. ETH, Zürich (in German)Google Scholar
  25. Pinkerton H, Norton GE, Dawson JB, Pyle DM (1995) Field observations and measurements of the physical properties of Oldoinyo Lengai alkali carbonatite lavas, November 1988. In: Bell K, Keller J (eds) Carbonatite volcanism of Oldoinyo Lengai—Petrogenesis of natrocarbonatite. Springer, Berlin, pp 23–36Google Scholar
  26. Rossi M, Gudmundsson A (1996) The morphology and formation of flow-lobe tumuli on Icelandic shield volcanoes. J Volcanol Geotherm Res 72:291–308CrossRefGoogle Scholar
  27. Rowland SK, Walker GPL (1987) Toothpaste lava: Characteristics and origin of a lava structural type transitional between pahoehoe and aa. Bull Volcanol 49:631–641CrossRefGoogle Scholar
  28. Self S, Keszthelyi L, Thordarson T (1998) The importance of pahoehoe. Ann Rev Earth Plan Sci 26:81–110CrossRefGoogle Scholar
  29. Thordarson Th, Self S (1998) The Roza member, Columbia River basalt group: a gigantic pahoehoe lava flow field formed by endogenous processes? J Geophys Res 103:27411–27445CrossRefGoogle Scholar
  30. Umino S, Lipman PW, Obata S (2000) Subaqueous lava flow lobes, observed on ROV KAIKO dives off Hawaii. Geology 28:503–506CrossRefGoogle Scholar
  31. Walker GPL (1991) Structure, and origin by injection of lava under surface crust, of tumuli, “lava rises”, “lava-rise pits”, and “lava-inflation clefts” in Hawaii. Bull Volcanol 53:546–558CrossRefGoogle Scholar
  32. Wilmoth RA, Walker GPL (1993) P-type and S-type pahoehoe: a study of vesicle distribution patterns in Hawaiian lava flows. J Volcanol Geotherm Res 55:129–142CrossRefGoogle Scholar
  33. Zaitsev AN, Keller J (2006) Mineralogical and chemical transformation of Oldoinyo Lengai natrocarbonatites, Tanzania. Lithos 91:191–207CrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2008

Authors and Affiliations

  1. 1.Institute for Mineralogy and PetrologySwiss Federal Institute of Technology (ETH Zürich)ZürichSwitzerland
  2. 2.Nordic Volcanological Center, Institute of Earth SciencesUniversity of IcelandReykjavikIceland
  3. 3.Swedish Museum of Natural HistoryStockholmSweden
  4. 4.Department of Geology and GeochemistryStockholm UniversityStockholmSweden

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