Mythical Wednesday: Exploding rocks.
May 13, 2015 4 Comments
Planet Earth is a strange and wonderful place. Just when you think you’ve seen it all, along comes something so unexpected, so weird, you just have to sit and shake your head. This is what I was thinking when I came across this article.
They call it ‘exfoliation’, and as you can see from the video, it happens suddenly, but not without warning. There are many places around the world where this type of geological phenomenon occurs. Typically in areas where there are exposures of uniform with coarse, crystalline igneous rocks. The majority of the rock mass is at a depth where it is under extreme high pressure from rock layers underneath it. It tends to be very uniform and lack any fractures which could be the reason it explodes. As the progressive erosion occurs, the rocks are subjected to pressure from overlying rocks, which leads to tension in directions at right angles to the surface. This tension is relieved by the formation of cracks, which follow the surface. They are relatively flat on plateaus, but can be steep on the flanks of mountains which are called exfoliation domes. The Yosemite’s spectacular Half Dome is the result of rock exfoliation. Once the cracks develop, water enters and causes chemical weathering which leads to the formation of new low-density minerals. This enhances the cracks and encourages slabs of rock to detach from the surface.
I don’t know about you, but as beautiful and exciting as this is, I’m sure it’s just as dangerous.