Radium Isotopes as Indicators of Pump Test Induced Changes in Fluid Composition; Fluid Age Dating by Means of 81Kr, 39Ar, 37Ar and 85Kr During the Long-Term Pumping Test 2002/2003 at the KTB Pilot Hole

本文通过测量镭同位素226 Ra、228 Ra、224 Ra、223 Ra和放射性惰性气体同位素39 Ar、37 Ar、85 Kr和81 Kr，研究了大陆深钻先导孔（KTB-VB）抽水试验过程中流体动力学及其水力学变化。这项研究的目的是从镭同位素比率中获得关于所开采流体的来源和流动路径的信息。此外，从镭同位素比值的测定可以推断出寄主岩石中流体-岩石相互作用的变化。氩同位素39 Ar和37 Ar的测量提供了关于地下产生的放射性核素（如36 Cl、129 I、14 C、4 He、3 He）从岩石到孔隙水中的产生速率和释放和转移过程的信息。将通过长寿命氪同位素81 Kr对开采流体进行年龄测定。我们的调查是对KTB-VB计划的其他地球化学和水力调查的最佳补充。通过对结果的综合，可以预期关于流体动力学的深远结论。

In this study the fluid dynamics and their hydraulically induced changes will be investigated by measurement of the radium isotopes 226Ra, 228Ra, 224Ra, 223Ra and the radioactive noble gas isotopes 39Ar, 37Ar, 85Kr and 81Kr during the pumping test at the continental deep drilling pilot hole (KTB-VB). The objective of the study is to derive information on the provenance and flow paths of the exploited fluids from radium isotope ratios. In addition changes in fluid rock interaction in the host rock can be concluded from the radium isotope ratio determinations. The measurement of the argon isotopes 39Ar and 37Ar provide information on the production rates and on the release and transfer processes of subsurface produced radionuclides (like 36Cl, 129l, 14C, 4He, 3He) from the rock into the pore water. An age dating of the exploited fluids will be performed by means of the long-lived krypton isotope 81Kr. Our investigations form an optimal supplement to other geochemical and hydraulic investigations planned at the KTB-VB. Far-reaching conclusions about fluid dynamics can be expected from the synthesis of the results.