Burial flow system

The resolution of groundwater dating (e.g., by 14C) in through-flow systems is reduced by dispersion and other flow-induced disturbances, such as deviation from piston flow. In this respect stagnant systems are advantageous because they carry the age signal of the time of burial with no further dispersion effects. 

Figure 2.30 Calculated distribution of gravity- and burial-induced groundwater flow systems in the Gulf of Mexico Basin for present-day and Miocene times (after Harrison and Summa, 1991, American Journal of Science, Vol. 291, Fig. 25. Reprinted by permission of American Journal of Science).

In summary, the evidence presented above is best interpreted as indicating that the arsenic enrichments found in Alabama bituminous coal was introduced following deposition and some (perhaps considerable) burial by the distal portion of a regional westward-directed metamorphic fluid-flow system. 

Transport in solution or aqueous suspension is the major mechanism for metal movement from the land to the oceans and ultimately to burial in ocean sediments. In solution, the hydrated metal ion and inorganic and organic complexes can all account for major portions of the total metal load. Relatively pure metal ores exist in many places, and metals from these ores may enter an aquatic system as a result of weathering. For most metals a more common sequence is for a small amount of the ore to dissolve, for the metal ions to adsorb onto other particulate matter suspended in flowing water, and for the metal to be carried as part of the particulate load of a stream in this fashion. The very insoluble oxides of Fe, Si, and A1 (including clays), and particulate organic matter, are the most important solid adsorbents on which metals are "carried."... 

Flow velocities of water in an aquifer, calculated by gradients and transmissivities, provide the maximum possible values. These are subject to limitations imposed by stagnation conditions. In extreme cases, confined systems may be rich in fossil karstic conduits, but with no through-flow due to complete confinement and/or burial beneath the level of the terminal base of drainage. 

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