Laterite Karst - large scale features

Large scale Laterite Karst features include the broad but shallow pans which are a distinctive features of many flat tropical plains which overlie a lateritic deep weathering profile (DWP). These are sometimes associated with shallow flat-bottomed and unchanneled valleys that are called "Dambos" in Africa. McFarlane & others (1995) describe examples from near Darwin, NT.

The hollows are assumed to be mainly a result of the removal of material in solution, i.e. silicate karst, but once formed deflation of seasonally dry pan surfaces may help to deepen and extend them.

Collapse dolines have been reported from the lateritic Stuart Plain of central Northern Territory (McFarlane & Twidale, 1987), but as the laterite is underlain at a depth of 50-100m by a limestone formation it may be that these are subjacent karst features rather than due to silicate solution.

Some duricrusts have strong jointing which forms fissures or cutters, and these can break up into "stone cities" analogous to those found in sandstone "silicate parakarst".

Further readings

  • Extracts from Grimes 1974. of sections discussing deep weathering profiles (laterites) and laterite karst features from a geological report on part of NW Queensland.
    Grimes, KG., 1974: Mesozoic and Cainozoic geology of the Lawn Hill, Westmoreland, Mornington and Cape Van Diemen 1:250 000 sheet areas, Queensland. Bureau of Mineral Resources, Geology & Geophysics, Australia, Record 1974/106 (unpublished).
    McFarlane, M.J., Ringrose, S., Giusti, L. & Shaw, P.A.,1995: The origin and age of karstic depressions in the Darwin - Koolpinyah area of the Northern Territory of Australia. in Brown, A.G. (editor) Geomorphology and Groundwater, Wiley, pp.93-120.
    McFarlane, M.J. & Twidale, C.R., 1987: Karstic features associated with tropical weathering profiles. Zeitschrift fur Geomorphology(NF), Suppl-Bd. 64: 73-95.

    Selected photographs and diagrams

    To view full size images, click on the displayed image.

    Solution Dolines, or "Pans"

    Aerial oblique view of a shallow pan on a lateritic plain in the Gulf of Carpentaria, Queensland.
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    Air photo of a group of laterite karst pans and dambos on a coastal plain in Cape York Peninsula, Queensland. The vegetation patterns reflect the degree of waterlogging in the soil.
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    Landsat image of unusually angular pans on the lateritic Doomadgee Plain, Gulf of Carpentaria, Queensland. See Extract from Grimes (1974).
    Doomadgee-123.jpg
    Air photo showing detailed view of the eastern part of the landsat image above.
    S74h-26.jpg
    Still closer detail of a laterite pan on the Doomadgee Plain, NW Qld.
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    Grey swampy soil on the floor of a laterite pan. Weipa, N. Qld.
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    Landsat image of the west coast of Cape York Peninsula, Queensland. On the eastern side, dambos and pans occur on a low-lying lateritic surface. Along the coast are Quaternary beachridges (Qp & Qh). The inner, last interglacial (Qp), ridges also have pans, but in that case the formation is probably solution of shelly material in the beach sands, rather than silicate karst.
    Holroyd2-123.jpg
    Air photo of another part of the same coast.
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    Landsat image of pans on the undissected parts of a low-lying laterite plateau. Arnhem Bay region, Northern Territory.
    ArnhemBay-123.jpg

    Giant grikes and Stone Cities

    Joint blocks in duricrust on the edge of a plateau form a small "stone city"
    Donors Plateau, NW Qld.
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    Ground view of the duricrust joint blocks.
    Donors Plateau, NW Qld.
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