Residence time of Chalk groundwaters in the Paris Basin and the North German Basin: a geochemical approach

Abstract

The comparative geochemical and isotopic study of confined and unconfined Chalk groundwaters of the Paris Basin and the N German Basin proves a significant chemical evolution during groundwater flow from the recharge zones to the deep confined aquifer. Different time dependent geochemical parameters have been tested as dating tools: Cation ratios (Sr

Persistent and emerging micro-organic contaminants in Chalk groundwater of England and France

“…Most groundwater was recharged during the Holocene and geochemical conditions are very similar in both basins with "fossil" groundwater being encountered in the confined part of the aquifer (Edmunds et al 1987;Kloppmann et al 1998). The presence of MOs suggests a rapid pathway and component of modern recharge in the Chalk.…”

“…Once organic contaminants move from the soil to the unsaturated zone the potential for degradation and attenuation is significantly diminished (Johnson et al 1998). The relationship between the Chalk and the overlying drift deposits are important in controlling hydrogeology and prevailing geochemical conditions (Edmunds et al 1987;Edmunds and Shand 2008;Kloppmann et al 1998;Lloyd and Hiscock 1990).…”

Paleowaters in Silurian-Devonian carbonate aquifers: Geochemical evolution of groundwater in the Great Lakes region since the Late Pleistocene

“…It is critical to understand the major sources and sinks for carbon in the groundwater flow systems to use carbon isotopes of DIC to estimate groundwater ages (Kloppmann et al, 1998). A plot of the activity of 14 C (in percent modern carbon) versus the d 13 C value of DIC illustrates the main geochemical processes affecting the carbon isotope The d 34 S value of gypsum and anhydrite in Silurian-Devonian bedrock in the study area ranged from 24.9 to 28.7&, whereas the d 34 S value of secondary gypsum in glacial drift deposits ranged from À14.8 to À8.2& (Eberts and George, 2000).…”

Diagnosing hydrological limitations of a land surface model: application of JULES to a deep-groundwater chalk basin

“…When model performance is poor in a particular hydrological aspect, model modifications are based on hydrological expert knowledge that, whilst subjective, is the only currently available way to adjust the model. The Kennet catchment in southern England is chosen as a complex case study that represents a number of the modelling challenges; however, the methodology and the results are of interest beyond this study due to the similarities across the hydrological modules of different third-generation LSMs, and also the broad importance of chalk aquifers and deep-groundwater systems (Brouyere et al, 2004;Downing et al, 1993;Kloppmann et al, 1998;Pinault et al, 2005;Dahan et al, 1998Dahan et al, , 1999Nativ and Nissim, 1992;Nativ et al, 1995).…”