 Salt is also bound within the matrix of the sediments, generally in pore waters, trapped during deposition.In a typical mud on the seafloor up to 90% of the sediment volume and mass is represented by hydrogen and oxygen either trapped in pore space as water or attached to phyllite minerals (clays) as hydroxyl bonds.During diagenesis, pore water is squeezed out of the sediments and, as burial continues and heat increases, water is liberated from clay minerals as the peripheral hydroxyl bonds are broken.