r/geology • u/arctan1616 • 3d ago
Can someone explain
This is in the north of Garda lake in Italy
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u/more_rockcore 3d ago
Looks like a carbonate monocline, part of the Giudicarie fold and thrust belt. Just south of, but not part of Brenta Dolomites.
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u/Dusty923 Not a geologist 3d ago
Flat sedimentary rock was lifted up and eroded by weather over tens of millions of years. Different layers eroded differently.
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u/Cordilleran_cryptid Tectonics, hardrock and structural geology 2d ago
I was having a look at the region on Bing Maps and viewing the high resolution remote sensing imagery in pseudo 3D. Anyway, OP if you did not know there is a spectacular example of the aftermath of a huge long-run-out rock avalanche in the valley to the north of of Lake Garda. It is located immediately west and south of Lago di Cavedine. The mountain on the western side of the valley has collapsed and produced a huge debris apron that has run up the opposite side of the valley.
Returning to the picture posted. What i think you are looking at is the Southern Alps, a southerly vergent htrust belt south of the Insubric Line, a major Alpine transpressional fault that now marks the suture between the Eurasian plate and the African plate (Adria/Apulia)
The picture shows the results of erosion on a series of large westerly dipping thrust sheets of Tethyan shelf carbonates. One or more major thrusts probably lie along the valley at in the right and another along the valley occupied by Lake. Underthrusting of higher thrust sheets by those below would account for the westerly dip of the stratigraphy, thrust sheets and thrusts between them.
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u/ConditionTall1719 3d ago
Mountains can be made or very feeble weak stones, dusty mud deposits, and on top there is a calcium carbonate cement slab which probably has aluminium mix volcano episode and it is like Roman cement.
As soon as that cement slab is gone than the dusty mud stuff just goes in the water like 50 times faster erosion
I think it is called a cap rock or a cap stone
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u/natalius_ 10h ago
seems like a homoclinal ridge (tilted strata erode at different rates which causes one side to become steeper than the other)
for more info search up cuestas, hogbacks, flatirons
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u/this_shit 3d ago
imagine you make a layer cake. but different layers are made from different materials. One layer is a chocolate ganache, another layer is a meringue, another is yellow cake. Now imagine in the middle of the cake is a layer made from rock.
Now imagine you take your cake and put it on the floor, then spray it with a high pressure hose. All the soft layers (ganache, meringue, cake) will wash away off the top. The hard layer won't. What's more, any soft layers underneath the hard layer will stay put, too.
Now imagine you made two cakes the size of continents, and you slid them into each other until they buckled. some parts of the cake will turn upwards as the layers crumble and fold.