The Lithification reference article from the English Wikipedia on 24-Apr-2004
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Lithification

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Lithification, from the Greek word lithos meaning 'rock', is the process whereby sediments compact under pressure, expel connate fluids and gradually become solid. Essentially, lithification is a process of porosity destruction through compaction. It is the final stage in the process of petrification. Lithification is also important in the creation of sedimentary rocks.