Przestrzenne związki pomiędzy rozmieszczeniem najwydajniejszych źródeł a neotektoniką w zlewni Białej Łady na Roztoczu Gorajskim (środkowo-wschodnia Polska)

Abstract

Spatial relationships between the distribution of springs with the highest discharge and the neotectonics of the Biała Łada catchment in the Goraj Roztocze region (central-east Poland).A b s t r a c t . Considerations of the relationships between the groundwater systems and neotectonics in the Roztocze region have been first undertaken by J. Malinowski in the 1970s. Until now, no research results have supported or challenged the hypothesis proposed by this author. Therefore, this paper is an attempt to present the results of a detailed analysis of the relationships between the distribution of springs characterised by the highest discharge rates and neotectonics. The study area covered the Roztocze part of the Biała Łada catchment, which has been subjected to detailed hydrogeological and hydrological investigations since the 1960s. The study was based on spatial data concerning the distribution of springs and information about the discharge rates of the largest springs. The data were juxtaposed with the relatively active tectonic zones distinguished in the catchment based on the relative tectonic activity index (Iat). The index was calculated using ArcGIS software, based on DEM, and with the use of the ArcNEO tool. The investigations indicated that springs with the highest discharge rates are located in the intersection zone of the main Biała Łada dislocation with accompanying faults. Additionally, the springs are located in the mouth sections of dry, asymmetric valleys and at the foot of their steep slopes following isostatically elevated hanging walls. The results support the hypothesis put forward by J. Malinowski (1993), who suggested that the distribution of springs with the highest discharge rates is determined by tectonics of the rock massif, in particular the distribution of the main dislocations and the accompanying subordinate discontinuous tectonic structures.