Structural Traps - the Thrust fault

Thrust faulting occurs when one section of the Earth is pushed up and over another section, and they most often occur in areas where two continental plates are running into one another. However, the photos below show sediments that were deposited by glaciers only 10,000 years ago, and these sediments were then run over by a glacial readvance. When the glacier moved back over the sediments, faulting occured. Can you see the faults below?

Now let's draw the faults and rock horizons in, and show how, if the conditions were right, oil might become trapped in this rock. If the rock between the yellow and red lines were sandstone, and rock beneath the red and above the yellow lines were shale, a trap might be set up in this way:


See how the oil gets trapped by the shale above it, as well as by the fault and the shale to the left of it? Of course, this outcrop is only a couple of meters wide, there really is no oil here, and the layers that we've assigned to the rock are mostly imaginary in this case. But the point is, this is exactly how many structural traps are set up below the Earth's surface. Here, we are lucky enough to see it right in front of our very eyes.

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