Tournaisian age of granitoids from the Odra Fault Zone (southwestern Poland): equivalent of the Mid-German Crystalline High?

The Odra Fault Zone of southwestern Poland is a NW-trending horst marked by gravimetric and magnetic anomalies and composed of high- to low-grade metamorphic and igneous rocks which are only known from boreholes. This zone embraces a concealed border between Variscan internides and externides. It also contains an array of several I-type, metaluminous to peraluminous, high potassic granitoid bodies which intruded earlier metamorphosed rocks. Except for one case, they remain unfoliated and undeformed, and presumably play a role of stitching plutons at the suture between two obliquely colliding terranes. U–Pb TIMS dating of single zircons from one foliated and one unfoliated granitoid samples yielded identical concordant ages of 344±1 Ma (Tournaisian). They resemble a Pb–Pb age of 350±5 Ma obtained for S-type granitoids from the Luckau area further west in Germany, which is generally regarded as an eastern segment of the Mid-German Crystalline High. Carboniferous granitic intrusions in the high are generally younger (340–290 Ma). Correlations of the the Odra Fault Zone with the Mid-German Crystalline High appear plausible, but by no means certain and require further confirmation.     

Identification of hydrogeochemical zones in postglacial buried valley aquifer (Wielkopolska Buried Valley aquifer,Poland)

This article presents the difficulty in identifying the hydrochemical zoning of a semi-confined aquifer, characterised by a relative small spatial differentiation of groundwater chemistry. It is shown that multivariate statistical methods can be used for the recognition and interpretation of the groundwater chemistry distribution in an aquifer. The hydrochemical zonation caused by both natural and anthropogenic processes was identified using factor analyses in combination with a classical interpretation of the hydrogeological material. The interpretation of the groundwater chemistry allows both identification of the aquifer recharge mechanism and verification of the groundwater-flow system.     

From peat bog to lignite seam: a new method to calculate the consolidation coefficient of lignite seams,Wielkopolska region in central Poland

Only one quantitative method is described in the literature to estimate the consolidation coefficient of lignite seams. More studies concentrate on the compaction of plant tissues, which explains why the obtained results are overestimated. Moreover, most studies do commonly not determine the consolidation of the whole peat bog but usually those of some of its elements only. We propose a new approach, which conceptually is fairly close to the Hager et al. (Fortschr Geol Rheinld Westf 29:319–352, 1981) method. Our method has been tested on an example of the first Middle-Polish Lignite Seam and the second Lusatian Lignite Seam from some Wielkopolska lignite deposits in central Poland. The consolidation coefficients, C _c, range between 2.34 and 2.56 for the second Lusatian Lignite Seam and between 1.80 and 2.14 for the first Middle-Polish Lignite Seam.