Zarys tektoniki obszaru lubelsko-lwowskiego

Abstract

OUTLINE OF THE TECTONICS OF THE LUBLIN-LVOV AREA (SE POLAND AND UKRAINE)SummaryThe Lublin-Lvov area is situated in the northern borderland of the Ukrainian massif bordered in the west by the younger Caledonian platform. The top of the crystalline basement submerges step-wise along a series of faults from the massif eastwards. In this area a number of tectonic units have been distinguished on the grounds of thickness differences of the sedimentary cover. Their distribution is demonstrated in Fig. 1.In that part of the Precambrian platform which was formed during Gothide time the sedimentary sequence commences – in the north – with the Polesie series subsequently intruded by gabbros. In the remaining area the sequence commences with the Vendian and in the northern Lublin area even with the Cambrian.West of the slope of the Ukraina in massif is the Mazovia-Lublin-Dniester graben stretching in the NW–SE direction. It is filled with Devonian and Carboniferous sediments overlying the Older Palaeozoic. Its age is Post-Westphalian and Pre-Permian ,its origin having been due to the pressure ·of the Caledonides thrusted over the platform. The SW fault of the graben is regarded as the boundary between the Precambrian and the Palaeozoic platforms.In the south-east the Mazovia-Lublin-Dniester graben is closed by the transversal Bukowina elevation responsible for the wedging out of the Carboniferous and Devonian sediments. Within the graben a number of elongated structural elements of horst-anticlinal character have been distinguished. Brachyanticlines developed in these elements. More gently dipping south-western limbs were thrust over steeper and less accentuated north-eastern limbs. In the south-west the graben is bordered by Sub-Mesozoic Devonian outcrops and in areas where erosion reached deeper levels – by folded Older Palaeozoic rocks. This area, called the Radom–Kraśnik elevation continues in Ukraine as the so called Nikolaev block. It is developed on the Epicaledonian platform whose upper stage was folded during Lower Siegenian time. The sedimentary cover, ultimately modelled during the Tertiary, was formed in a number of cycles that produced 5 complexes (Fig. 2),