Przejawy młodej aktywności tektonicznej w Dolinie Kielecko-Łagowskiej w Górach Świętokrzyskich i jej wpływ na układ sieci wodnej

Abstract

MANIFESTATIONS OF YOUNG TECTONIC ACTIVITY IN KIELCE-ŁAGÓW VALLEY (HOLY CROSS MTS, CENTRAL POLAND) AND THEIR INFLUENCE ON THE RIVER SYSTEM Summary Kielce-Łagów Valley is one of the main five morphostructural units in the frame of the Holy Cross Mts. Paleozoic core. It was formed along the contact zone of two Iitospheric blocks separated by the deep Holy Cross fracture (Fig, 2, 3). On its borders it constitutes a morphological reflection of the Paleozoic Kielce-Łagów synclinorium due to the undation-blocky movements, which have restored the Palaeozoic structure of the Holy Cross Mountains complex during the late Tertiary (Fig. 4, 5). The river network of the area, which survived from the early Tertiary period is characterized by nearly transversal arrangement in relation to the Paleozoic structures, and by distinct evidences of the neotectonic reconstruction. This reconstruction is the result of restoration local folds (anticlines and synclines), as well as some transversal elevations and depressions (Fig. 6). At the junctions of these unstable tectonic elements appeared the geodynamic nodes of four types (Fig. 7): AE (at the junction of anticline and elevation), AD (anticline and depression), SE (syncline and elevation), and SD (syncline and depression). At these junctions the tectonic tendencies are summed up (AE++ and SD--), or reduced completely or partially (AD+-) and SE-+). Moreover the nodes created by the junctions form 3-4 longitudinal zones-strips, which coincide with the anticlines and syncIines (Fig. 6). The neotectonically active anticlines and syncIines make impediments for rivers and force them to change their directions. Traversing of these impediments by the re-shaped rivers takes its place at the nodes of SD and AD types, and seldom at SE type (Fig. 7,9-12). Observations of the primary river pattern carried out in the Kielce-Łagów Valley provide us with evidences for the younger Neogene and even Quaternary (?) tectonic activity, leading to the restoration of local anticlines and synclines as well as some elevations and depressions. The tectonic stress which induced this activity migrated laterally from the Carpathian tectogene and its foredeep which were shaped in the early Tertiary.