1 Introduction ................................................. 9
2 The hydrogeological investigation programme at Gorleben ..... 10
3 Morphology and hydrology of the study area .................. 13
3.1 Location, morphology, hydrography, land use ............ 13
3.2 Climate and precipitation .............................. 16
3.3 Groundwater recharge ................................... 17
4 Overburden hydrogeology ..................................... 20
4.1 Introduction ........................................... 20
4.2 Hydrostratigraphic classification of the sedimentary
sequence ............................................... 20
4.2.1 Tertiary ........................................ 22
4.2.2 Quaternary ...................................... 24
4.3 Hydrogeological structure .............................. 25
5 Hydraulic properties ........................................ 31
5.1 Long-term pumping tests ................................ 32
5.1.1 Objectives ...................................... 32
5.1.2 Evaluation method ............................... 34
5.1.3 Results ......................................... 35
5.1.3.1 Hydraulic parameters ................... 35
5.1.3.2 Spatial drawdown behaviour over time ... 36
5.2 Hydraulic conductivity ................................. 40
6 Geothermal investigations ................................... 43
6.1 Objective .............................................. 43
6.2 Datebase ............................................... 43
6.3 Expected geothermal field .............................. 44
6.4 Groundwater temperatures in the overburden ............. 44
6.5 Distribution of heat flow density ...................... 45
6.6 Thermal indications of groundwater flows ............... 50
7 Hydrochemistry .............................................. 55
7.1 Spatial distribution of total dissolved solids ......... 55
7.1.1 Data evaluation procedure ....................... 55
7.1.2 Description of freshwater/salt water
distribution .................................... 57
7.2 Chemical composition of the groundwater ................ 66
7.2.1 Groundwater classification ...................... 66
7.2.2 Geochemical interactions between groundwater
and sediments ................................... 69
7.2.1 BGR
7.3 Isotope-hydrological investigations .................... 74
7.3.1 Tritium ......................................... 74
7.3.2 Stable oxygen and hydrogen isotopes ............. 76
7.3.3 14C age dating .................................. 82
7.3.4 Analysis of core samples from the Hamburg-Ton
and Lauenburger-Ton-Komplex ..................... 86
8 Groundwater dynamics ........................................ 91
8.1 Groundwater levels ..................................... 91
8.2 Groundwater dynamics in the freshwater body ............ 95
8.2.1 Shallow groundwater ............................. 95
8.2.2 The freshwater body of the lower aquifer in
the Elbe-Löcknitz lowland ....................... 99
8.3 Groundwater dynamics in the salt water body ........... 100
9 Numerical groundwater modelling ............................ 103
9.1 Three-dimensional groundwater model with constant
density ............................................... 103
9.2 Modelling of groundwater flow with variable
densities ............................................. 106
9.3 Paleohydrogeological investigations ................... 110
9.4 Conclusions from groundwater flow modelling ........... 114
10 Final discussion on freshwater/salt water dynamics within
the overburden of the Gorleben salt dome ................... 115
References ................................................. 132
Abbreviations .............................................. 139
List of tables ............................................. 141
List of figures ............................................ 142
List of appendices ......................................... 145
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