The article is focused on the most recent investigations of glaciotectonic structures in high escarpment exposures of the Vistula valley from Dobrzyń to Kuzki in the western part of the Płock Basin. Deformations involve Neogene and occasionally the Lower Pleistocene deposits and they are not expressed as landforms. Structural investigations and analysis of archival geological data provided new information on the origin of large-scale shear structures. Results obtained are clearly contrary to the concept of Brykczyński (1982) regarding valley-side glaciotectonics in the Płock Basin. An emergence of the extensive zone of serial thrust structures of significant amplitude (up to 100–150 m) was found to have not been controlled by a palaeovalley. A driving mechanism is interpreted as a gravity spreading in front of ice sheets advancing from north-northeast during the South Polish Complex (Dorst-Elsterian).
This paper proposes a modification of the classical process for evaluating the statistical significance of displacements in the case of heterogeneous (e.g. linear-angular) control networks established to deformation measurements and analysis. The basis for the proposed solution is the idea of local variance factors. The theoretical discussion was complemented with an example of its application on a simulated horizontal control network. The obtained results showed that the evaluation of the statistical significance of displacements in the case of heterogeneous control networks should be carried out using estimators of local variance factors.