CUTTER & PINNACLE
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| UPDATE: Crash Kennedy in Texas tells me that this kind of karst topography is called cutter and pinnacle topography, "Pinnacles being the rock sticking up out of the soil, of course. Pinnacles can also be entirely soil-covered. You see good examples around the Mammoth Cave area in Kentucky, where they have been exposed in roadcuts along the interstate. These are actually quite common in karst areas of the world, differing only in scale. |
I suspect there's a good term for describing this particular kind of karst topography (see right), karst being "An area of irregular limestone in which erosion has produced fissures, sinkholes, underground streams, and caverns."
If you start with a flat layer of exposed limestone, inevitably it'll be crisscrossed with fractures. Natural rainwater is slightly acidic, so where it enters the fractures it dissolves away the stone, eventually producing deep fissures. These fissures are called "grikes" and the flat, often rectangular slabs between them are called clints. Collectively such systems are referred to as "karren" or "lapiez."
Atop Cocos's mountains the emergent limestone is much too irregular and the spaces between the outcrops are far too wide to be called "grike & clint" topography. However, I wonder if once the wide spaces might have been grikes, and the irregularly shaped rocks, clints.
Whatever the technical term for such physiography, the landscape is a pretty one to walk through, each sculptured rock expressing its own history and view of things, and the area as a whole constituting a very special ecosystem.