Fossil groundwater

Nonreplenishable (fossil) groundwater can be tapped, but such extraction depletes reserves in much the same way as extractions from oil wells do. The terrestrial renewable freshwater supply, RFITTj, equals precipitation on land, which then subdivides into two major segments evapotranspiration from the land, and mnoff to the sea, T. Because groundwater and surface water are often hydrauhcaHy coimected, soil infiltration and groundwater... 

The fossil water is characterised by high total mineralization as a result of long residence times in the subsurface as well as by lower 2H and 180 isotope values as a result of the lower temperatures during formation (Table 37). The different amounts of 13C can be explained by the establishment of equilibrium of the fossil groundwater with marine limestones with higher amounts of 13C than recent groundwater, which reflects the lower concentrations of 13C in the atmosphere. 

Table 37 Water analysis of a fossil groundwater (pH = 6.90, temperature = 40 °C, concentrations in mg/L)...

Table 47 Two models, showing the share of fossil groundwater compared to recent groundwater in an arid region (precipitating mineral phases +, dissolving mineral phases -, concentration in mol/L)...

Rain in equilibrium with atmospheric C02, but uncontaminated by industrial emissions, should have a pH of 5.7. However, atmospheric pollution from burning fossil fuels has resulted in acid rain of pH as low as 3.5 (24). If this condition continues for a long time, it may lead to a change in groundwater composition, which may considerably change the migration of plutonium in nature. 

The course taken by any particular fossilization process is, therefore, determined by the physical and chemical factors prevalent in the environment of the dead remains. The physical factors include temperature, degree of aeration, and rate of flow of groundwater. The nature of minerals and rocks, and of the groundwater at the site of burial, are the most important chemical factors. Reconstructing and explaining the processes undergone by dead remains, from the time of death to when they are fully fossilized, is the concern of taphonomy, the study of the processes taking place when dead remains pass from the biosphere to the lithosphere (see Textbox 69). 

PAHs are released to the environment from a number of sources pyrogenic sources including fossil fuel combustion and pyrolytic processes of organic matter such as incineration and petrogenic sources such as oils spills. Direct oil spilled from stationary sources and accidents cause contamination of land. Oil spills at US Army bases in South Korea is reported as a source of soil and groundwater contamination to nearby area... 

Fig. 2.10 Rock beds in a subsidence basin. The part above the terminal base of drainage, for example, the sea, functions as a through-flow system (arrows). The deeper rock beds are fossil through-flow systems that host stagnant groundwater as they are (1) covered by impermeable rocks, (2) bisected by plastic impermeable rocks that have been squeezed into stretch joints in the competent rock beds and in between bedding plane thrusts, and (3) placed in a zone of zero hydraulic potential.

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