Erosional Landforms (3)
This section provides an overview of erosional landforms found predominantly in limestone regions. It describes several types of landforms, primarily focusing on swallow holes, sinkholes, and caves.
Key Concepts:
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Swallow Holes and Sinkholes: These are shallow depressions formed through dissolution in limestone. Sinkholes are more extensive, regularly appearing circular vanishes in the ground that can range in size and depth, and they typically occur in karst terrain.
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Types of Sinkholes: Sinkholes can be categorized into solution sinks, resulting from direct dissolution, and collapse sinks, caused by the collapse of the earth above a cave or void. The term 'doline' is often used interchangeably with collapse sinks.
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Valley Sinks/Uvalas: When multiple sinkholes coalesce due to slumping or roof collapses, they can form long, narrow to wide trenches known as valley sinks or Uvalas.
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Lapies: These are sharp ridges left behind on limestone surfaces caused by the differential solution activity—characteristic due to joints in the limestone.
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Cave Formation: The section also addresses how caves form in regions with alternating layers of limestone and other rocks. Water percolates down through cracks, eroding the limestone along bedding planes, resulting in various cave systems.
These erosional processes not only shape the landscape but also contribute to unique ecosystems found in karst areas.