Founded in 1580 by the Austrian Archduke Charles, it lies on a plateau of porous rock just above Trieste.

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The key challenge lies, of course in tapping into the juice, most of which is buried beneath layers of porous rock formations called shale.

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Under pressure, these hydrocarbons squeezed through grainy, porous sedimentary rock until blocked by nonporous rock, known as capstone.

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Lastly, it needs to be covered with a layer of non-porous, non-cracked rock to provide a leakproof cap.

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