Sandstone Caves in Venezuela

[rhychydwr1]

BBC1 I-Player  Steve Blackshaw Extreme Mountain Challenge Episode  2 about 22 minutes in.

 

[Alex]

Yeh that's been on before, but that's rather cool. I guess the sandstone is more sandstone limestone as they say it dissolves, maybe it's glued together with limestone?

Looks like a big cave anyways, I would love to visit and explore the area.

 

[langcliffe]

Yeh that's been on before, but that's rather cool. I guess the sandstone is more sandstone limestone as they say it dissolves, maybe it's glued together with limestone?

Looks like a big cave anyways, I would love to visit and explore the area.

Quartzite, actually. This is only marginally soluble, so the caves form over tens of million years, rather then tens of thousands years which is more typical of normal karst.

 

[Graigwen]

It is the cement that dissolves, not the quartz grains. So you just end up with a pile of quartz grains, as demonstrated.

As the solution is uneven, often occurring along joints, flat slabs of almost unaltered rock may spall from the roof.

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