This is a peculiar process of geomorphology, where a landscape evolves so that its high points become the low points, and the low points become high points. Topographic inversion invariably happens because of the patterns of resistant rocks in the terrain.

Volcanic topography inversion

An ordinary stream valley (1) is a low spot in the terrain, and a natural channel for the flow of molten lava. After the lava cools, it fills in the valley (2). Now it may happen that the hardened lava is more resistant to erosion than the surrounding country rock. If so, the uplands surrounding the lava flow's valley will erode away until only the lava flow is left, revealing a long ridge where there was once a valley (3).


`-._       _.-'             `-._       _.-'   
    `-._.-'                     `^*#*^'                  _____.*#*.____

      (1)                         (2)                          (3)

Topography inversion in folded mountains

As a resistant layer in folded mountains is revealed, the tops of the anticlines are revealed as the tops of ridges, and the bottoms of the synclines become valleys (4). But the tops of the anticlines are the least resistant part of the resistant layer: They've been weakened the most by bending stress, and they're exposed, unlike the bottoms of the synclines, protected by sediment.

As time passes, the tops of the ridges are eroded as the weather widens stress cracks there. Eventually, the less-resistant layer is revealed (5). More time passes, and valleys erode into the anticlines (6). In the final stage, the only bit of the resistant layer left is the bottom of the syncline (7). Once a low point, now a high point.

     
   .-===-.         .-===-.   
  //     \\       //     \\ 
 //       \\_   _//       \\
//         `-=-=-'         \\
/                           \
             (4)

                       
   .-___-.         .-___-.   
  //     \\       //     \\ 
 //       \\_   _//       \\
//         `-=-=-'         \\
/                           \
             (5)
      
  _       _       _       _
 //\_   _/\\_   _//\_   _/\\
//   `-'   `-=-=-'   `-'   \\
/                           \
             (6)

 
 _ 
//\          ---           _
/  \________/   \_________/\\
             (7)

Topography inversion because of deposition conditions

Sedimentary Rock layers can create topography inversions simply because of the conditions of their deposition. For example, starting in the Cambrian Period 600 million years ago, a shallow geosyncline between two southward projections of the Canadian Shield was filled with a shallow sea (now called the Michigan Sea). During the Silurian Period, a limestone layer was deposited in the bottom of this sea, near the coastline. Other layers filled in on top of this layer, some more resistant others less. But the limestone was transformed into the much harder Niagara Dolomite. Fast forward to the Pleistocene, when continental ice sheets advanced and retreated over North America. Lobes of the glacier slid on top of the Niagara Dolomite, and ground away at the edges of the layers that had been deposited on top. Today, the Lower Peninsula of Michigan sits in what was once the depression of the Michigan Sea, with Lake Huron to one side and Lake Michigan on the other. (A remnant of the dolomite layer survives as the Niagara Escarpment.)

              ____________
          _.-'            `-._                    
       .-'                    \
      /                        \
     /                          \             
    /                            \            \\_                     _//
   /                              \            `-:-------------------:-'
  /                                \                
 /                                  `-._           (dolomite forms in
|                                       `-.          shallow sea)
|
|                                              \\=======================//
 \                                              `-:===================:-'
  \                                           
          (before: Michigan Sea)                     (other sediments 
                                                       fill in sea)
                     ___
            _____ ______\ ______               #############################
        _.-'     '        --._ /               ########========#############
       /        ( `-._        ` _                \\###==========######//
      /_        /     |         \\         
     ///     /`'      |          )`._              (much later: ice
    ///     /         |         /                   chews into thinner      
     /     /         /         /                    resistant layers
    /     |         /  .-.    |                     at the edges  )
   /      |        (__/   |   |
  |        \              |  .'                 __     --------        __
  |        |              |-'                    \\www==========wwwwww//
  |        |             /                    
  |       /             /                                  (Today)
   \     /_____________/
    \_.-'


         (after: Michigan)

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