|Latitude & Longitude (WGS84):||2° 45' 0'' South , 35° 55' 59'' East|
|Latitude & Longitude (decimal):||-2.75000,35.93333|
|Köppen climate type:||Aw : Tropical savanna, wet|
The world's only active carbonatite volcano, with jacupirangite, nepheline syenite and other rocks. Extremely alkali-rich lava, 30 % Na2O.
61 valid minerals. 4 (TL) - type locality of valid minerals.
Rock Types Recorded
Select Rock List TypeAlphabetical List Tree Diagram
Entries shown in red are rocks recorded for this region.
This geological map and associated information on rock units at or nearby to the coordinates given for this locality is based on relatively small scale geological maps provided by various national Geological Surveys. This does not necessarily represent the complete geology at this locality but it gives a background for the region in which it is found.
Click on geological units on the map for more information. Click here to view full-screen map on Macrostrat.org
|Holocene - Pleistocene|
0 - 2.588 Ma
|Main-cone volcaniclastic rocks and lava flows|
Age: Pleistocene (0 - 2.588 Ma)
Description: Stippled on northwest flank where pyroclastic flow(?) deposits of 2007–08 can be delineated from oblique photography. Less well-defined lava flows are contained within this unit. Lava flows: chiefly nephelinite and phonolite, but includes recent carbonatite on west flank. Subdivided into: Holocene carbonatite lava flows, Pleistocene nephelinite of upper flanks, and Pleistocene phonolite lava flow on lower east-southeast flank. Carbonatite lava flows: Pāhoehoe and ‘a‘ā of 2006 eruption. Nephelinite of upper flanks: remnants of lava flow, highest part of which is sometimes called “Pearly Gates” for the slot traversed through it by westside climbers’ trail
Reference: Sherrod, D.R., Magigita, M.M., and Kwelwa, S. Geologic map of Oldonyo Lengai (Oldoinyo Lengai) and surroundings, Arusha Region, United Republic of Tanzania. doi: 10.3133/ofr20131306. U.S. Geological Survey Open-File Report 2013-1306. 
0 - 2.588 Ma
2.588 - 23.03 Ma
|Cenozoic volcanic rocks|
Age: Neogene (2.588 - 23.03 Ma)
Reference: Chorlton, L.B. Generalized geology of the world: bedrock domains and major faults in GIS format: a small-scale world geology map with an extended geological attribute database. doi: 10.4095/223767. Geological Survey of Canada, Open File 5529.