Antyklina Opole Lubelskie–Zakrzew

Abstract

ANTICLINE OPOLE LUBELSKIE–ZAKRZEW  (CENTRAL LUBLIN REGION)SummarySome Late Plalaeozoic structural units are known to occur in the basement of the Mesozoic Lubin trough. These units are separated by a south-west trending marginal fault of the Mazowsze–Lublin graben. In the SW part the Devonian sediments of the Radom–Kraśnik elevation occur under the Jurassic, and in the NE part – there are found Carboniferous sediments that fill in the Mazowsze–Lublin graben (Figs. 1–2). At the boundary of these two units – already within the area of the Radom – Kraśnik elevation – an anticline occurs, its amplitude being up to 200m. Within this anticline, thickness of the individual members, younger than the Lower Devonian, decreases as compared with the thickness of these stratigraphical members in the adjacent areas. This corresponds to a twofold decrease in thickness of the Middle Devonian – in relation to the thicknesses observed within the areas situated to the north-east, and to a more than fourfold decrease in the areas situated to the south-west. The reduction in thickness of the Upper Devonian formations in the NE limb is threefold, provided that, within the anticline, the Frasnian reef formations are thicker. According to the present author, this may be explained by a greater stability here. The Carboniferous formations investigated within the eastern margin, and the analysis point to a reduction in their thickness towards the palaeoanticline. Both Permian and Triassic formations found to occur in the north-eastern part of the anticline, disclose a reduction in thickness, and a wedging out of sediments towards the axis of the structure. The best picture of the palaeoanticline can be observed in Jurassic formations that rest in its south-eastern part. The culmination lacks here any Dogger members, and the Oxfordian deposits are lesser in thickness. Dogger deposits appear only in the synclines that surround the anticline. Here, the thickness of the Oxfordian deposits increases. A reaction of the Kimmeridgian deposits, still preserved under the Cretaceous formations, may be related to the synsedimentary decrease in their thickness near the axis, as well as to the denudation during the Young Cimmerian phase. The data, we have so far obtained from the Cretaceous formations, do not permit us to draw conclusions as to any development of this form at that time. In the light of the above evidences, a palaeoanticlinal area existed from Middle Devonian to Upper Jurassic, within the marginal area of the Radom – Kraśnik elevation, at the boundary with Mazowsze – Lublin graben. This palaeoanticline is related by the present author to the marginal area of the Caledonian platform overcrust on the Precambrian one (Fig. 2)