Fennoscandian shield

For a waste storage site a fault-free block surrounded by faults at some distance (a few km away) would be required. Such areas can be found at many locations within the Fennoscandian shield. 

Ekendahl, S., O Neill, A. H., Thomsson, E. Pedersen, K. (2003). Characterisation of yeasts isolated from deep igneous rock aquifers of the fennoscandian shield. Microbial Ecology, 46, 416-28. 

Lower-crustal xenoliths from the Archean part of the Baltic (or Fennoscandian) Shield, like their post-Archean counterparts, are dominated by mafic lithologies (Kempton et al., 1995, 2001 Markwick and Downes, 2000 Holtta et al., 2000). Most equilibrated at depths of 22-50 km and contain hydrous phases (amphibole biotite). Partial melting and restite development is evident in some migmatitic xenoliths, but cumulates are... 

Figure 1 Heat production data for several well-sampled provinces (a) the Archean Yilgam craton of Western Australia, (b) the Proterozoic Gawler craton of Central Australia, and (c) the Proterozoic Fennoscandian Shield (sources Australian data—Heier and Lambert (1978) Fennoscandian data—Hanski (1992), Eilu (1994),...

These arguments can be refined. In Appendix B, we calculate the mantle heat flow as a function of lithosphere thickness and show how it depends on the surface heat flow. Pressure and temperature estimates from mantle xenoliths may be combined to determine a best-fit geotherm consistent with heat transport by conduction. Mantle heat flow estimates obtained in this manner are in the following ranges 7-15 mW beneath the Fennoscandian Shield (Kukkonen and Peltonen, 1999), 17-25 mwm for the Kalahari craton. South Africa (Rudnick and Nyblade, 1999), and... 

Killeen P. G. and Heier K. S. (1975a) A uranium and thorium enriched province of the Fennoscandian Shield in southern Norway. Geochim. Cosmochim. Acta 39, 1515-1524. 

Kukkonen 1. T. and Peltonen P. (1999) Xenolith-controlled geotherm for the central Fennoscandian Shield implications for lithosphere-asthenosphere relations. Tectonophysics 304, 301-315. 

Stable chlorine isotope data from the Canadian and Fennoscandian shields... 

Figure 4 The and 8 H isotopic values for methane gas found dissolved in saline groundwaters from several sites on the Canadian and Fennoscandian Shields (samples for each area are circled). These are compared to the bacterial and thermogenic ranges of Schoell (1988). and Bp are the ranges as outlined by the boxes of bacterial methane production from CO2 reduction and acetate fermentation, respectively (Collar et al. 1993b) (reproduced by permission of Elsevier from Geochim. Cosmochim. Acta, 1993, 57, 5087-5097).

Fennoscandian Shield after the last glacial retreat (Nurmi et al., 1988 Lahermo and Dampen, 1987 Smellie and Wikberg, 1991). Such events in coastal areas under the right conditions, such as isostatic rebound, may be very common. With time, and uplift and freshwater infiltration, some or aU of these shallow emplaced seawaters may eventually be flushed from the rock mass. 

During the last million years the area has been subjected to several glaciations, the last of which (Weichselian Ice Age) ended 10" yr ago (Conner, 1995). It is estimated that the maximum thickness of the continental ice cover in the central part of the Fennoscandian Shield was 3 km some 2 X 10" yr ago. The weight of the ice depressed the underlying crust by up to 800 m at the center of the glaciated area (Niskanen, 1943 Mdrner, 1979). At Palmottu the depression was less, —300-400 m, but here the isostatic rebound... 

Blomqvist R. (1999) Hydrogeochemistry of Deep Ground-waters in the Central Part of the Fennoscandian Shield. Report YST-101, -41. Geological Survey of Finland. Nuclear Waste Disposal Research. 

Blomqvist R., Vuorela P., Nissinen P., Ruskeeniemi T., Frape S. K., and Ivanovich M. (1993) Crustal rebound-related groundwater flow and calcite formation in the crystalline bedrock of the Fennoscandian shield new observations from Finland. Extended Abstract for the OECD Meeting, Workshop on paleohydrogeological methods and their applications for radioactive waste disposal, 5p. 

Sherwood LoUar B., Frape S. K., Drimmie R. J., Fritz P., Weise S. M., Macko S. A., Welhan J. A., Blomqvist R., and Lahermo P. W. (1989) Deep gases and brines of the Candian and Fennoscandian shields—a testing ground for the theory of abiotic methane generation. In Proc. 6th Int. Symp. Water—Rock Interaction (ed. D. L. Miles). Malvern, UK Balkema, Rotterdam, Netherlands, pp. 617—620. 

Tullborg E. L., Larson S. A., and Stiberg J.-P. (1996) Subsidence and Uplift of the Present Land Surface in the Southeastern Part of the Fennoscandian Shield. Report 112, Stockholm, Geologiska Foreningens i Stockholm Forhan-dUngar, pp. 215-225. 

Karhu J. A. (1993) Paleoproterozoic evolution of the carbon isotope ratios of sedimentary carbonates in the Fennoscandian Shield. Geol. Soc. Finland Bull. 371, 87. 

Caledonides, with elevations up to 2470 m, and the surface of crystalline Precambrian rock of the Fennoscandian Shield were shaped by glacial erosion, whereas the lowlands of the Russian Plate and West European Platform are covered by glacial sediments. 

The following mechanical properties were assumed for the rock mass density = 2650 kg.m Young s modulus = 35 GPa, Poisson s ratio = 0.22, cohesion = 5 MPa and internal friction angle = 30. For the fracture zones Young s modulus = 3.5 GPa, cohesion = 3 MPa and friction angle = 25°. Biot s hydroelastic coefficient, a, was assumed to be 1 everywhere. In situ stresses were assumed to correspond to mean values for the Canadian and Fennoscandian Shields. These increase with depth, with the maximum principal stress in the horizontal NE-SW direction. 

When the construction work for the tunnels was started. Great Belt A.S. had not yet provided reliable heights (first order control) for points at Sprog0 island. The available heights at this time were based on a hydrostatic levelling carried out in 1938 (Norelund, 1945). Due to a possible uplift of the Fennoscandian Shield, the old value... 

Canadian and Fennoscandian shield [44], and Witwatersrand Basin, South Africa [45]. This mechanism is generally most important for granites, in which the content of the principal radiogenic elements U, Th, and, K is generally highest among crustal rock types [46]. 

Geochemistry and origin of saline ground-waters in the Fennoscandian Shield. Applied Geochemistry, 3, 185-203. 

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