Water entrapped in the interstices of the rock (either sedimentary or extrusive igneous) at the time the rock was deposited. It may be derived either from ocean water or land water. Often used incorrectly to denote [[formation water]] or [[interstitial water]]. The composition of the original water may have been altered during the compaction process by entrapment of ions, extrusion of water, [[diffusion]], [[osmosis]], etc.