Gravity-induced groundwater flow system

T6th describes the gravity-induced groundwater flow pattern in terms of interdependent flow systems as existing in drainage basins. A drainage basin is a depression of the ground surface, partly or entirely surrounded by 

Concentration of groundwater flow towards narrow concave side B of the basin 

Garven and Freeze, 1984a,b T6th, 1962,1963,1978) indicate that 

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Lateral variations in permeability, caused by e.g. facies changes unconformities, faults, can profoundly affect the gravity-induced groundwater flow system (Figure 2.24), which in some cases can lead to the creation of local flow systems (Garven and Freeze, 1984b). 

The chemical characteristics of groundwater of meteoric origin change systematically in the direction of flow in a gravity-induced groundwater flow system (Bredehoeft et al., 1982 Collins, 1975 Herczeg et al., 1991 Tdth, 1980). The... 

Figure 2.31 Calculated increase in basinward extension of the gravity-induced groundwater flow system in the Gulf of Mexico Basin resulting from a 200 m fall in sea level during the Oligocene (after Harrison and Summa, 1991, American Journal of Science, Vol. 291, Fig. 26. Reprinted by permission of American Journal of Science).

Figure 5.13 Cross-section of a horizontally layered drainage basin showing positions of hydraulic traps in connection with the gravity-induced groundwater flow systems (modified after Tdth, 1980. Reprinted by permission of the American Association of Petroleum Geologists).

After the probable depth of penetration of the regional gravity-induced groundwater flow system has been identified, it should be decided whether or not the gravity-induced flow system should be taken into accoimt in the further evaluation of the potential paths of hydrocarbon migration. 

The hydrodynamic condition in a stable subaerial region is given by the characteristics of the prevailing gravity-induced groundwater flow systems. 

The present-day groimdwater flow systems in the selected study area may not be in accordance with the relief of the present-day water table, and as a consequence the characteristics of the flow system cannot be reliably inferred solely from water table relief and subsurface permeability distribution. A direct determination of the quantitative characteristics of the present-day gravity-induced groundwater flow system, requires data on pressure, density and viscosity of groundwater and data on the permeability distribution... 

T6th (1978) proposed an analysing technique for the quantitative assessment of cross-formational gravity-induced groundwater flow systems and the genetic explanation of the identified systems, based on the integrated interpretation of the following five pressure-related parameters ... 

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