Tectonic deformation in the East European Craton (Baltica) and Malopolska Block (European Palaeozoic Platform) border zone (TESZ) – The structural evolution of Cambrian sediments in the exploration boreholes

The boreholes Wola Obszańska-8, Księżpol-12 and Dzików-17 are located in the NE marginal zone of the Małopolska Block. It is situated beside the Holy Cross dislocation, which probably continues in this region and divides the Małopolska Block from the Łysogóry Block. The Malopolska Block occurs at south western foreland of the East European Craton within the Central European part of the Palaeozoic Platform. They are components of a collage of crustal blocks of various age and origin (Trans-European Suture Zone).
   The exploration boreholes Wola Obszańska-8, Księżpol-12 and Dzików-17 were drilled of the Cambrian and were cored in part. The exploration borehole Wola Obszańska-8 was drilled to 1100m. Was cored examine in parts: 1100,0 – 1093,0, 1069,0 – 1060,0, 1012,0 – 1003,0 (The Upper Cambrian). The borehole Księżpol 12 was drilled to 978m and was cored in part to -in interval 946,0 – 955,0 are measures The Upper Cambrian. The borehole Dzików-17 was drilled to 1108m and was cored in part: 1108-1099, 1040-1031 and 1031-1022 (The Middle Cambrian).
   These sediments are poorly and strong involved tectonic. Sediment layers are mostly placed horizontally, vertical and sub vertical. These sediments in these boreholes display large variability of pitch of sedimentary surfaces. Angle of fall oscillates within bounds: 0-90 degrees. In the borehole Księżpol-12 angle of fall oscillate within bounds: 5-65 degrees (layers are inclined high – pitched) and in the borehole Wola Obszańska 8, layers fall into in generally to angle 0-20 degrees (are display horizontal, subhorizontal fall). In the exploration borehole Dzików-17 angle of fall oscillate within bounds: 30-90 degrees.
   The main part in sediments of the Cambrian is dark gray mudstones. In their area are situated into some centimeters interval alternate thin layer dark gray claystones and mudstones, light gray sandstones. Sediments of the Upper Cambrian in the borehole Wola Obszańska-8 are represented by middle and thick granular quartzites and argillie and slime litofacies. Quartzites have mild and mosaic texture. Their development point out to highenergy environment of sedimentation. In these sediments dominate cracks which angle of pitch oscillate between: 70°-90° (high-pitched, subvertical, vertical) -D1. Younger, subhorizontal cracks (D2) which displace older cracks rarely appear. On surfaces of cracks there are lots of minerals of iron and sometimes in places where sandstone contact with argillie beds there are horizontal cracks with slips. Dominant role in the Cambrian sediments perform argillie and slime sediments within which appear very thin laminas of light gray sandstones which course is very perturbed (discerpted and folded). Within these sediments dominate interlaminar, horizontal and subhorizontal cracks. In the exploration borehole Księżpol-12 are dominate cracks younger, subhorizontal D2. Subhorizontal cracks often displace vertical cracks. On surfaces of cracks there are lots of minerals of iron. Sometimes in place where sandstone contacts with argillie beds there are horizontal cracks with slips.
   In works of the centre Cambrian the following structural result was stated (for example the exploration borehole – Dzików 17) : 1 - coming into existence of sedimentary areas of S0 and diagenetic structures, 2 – being formed in conditions subhorizontal of countermove of the macrocrease, into which steep wing an analysed hole was carried out, 3 – activity of susceptible-brittle normal-slip faults, which transfers stole according to previously steeply adjusted lamellose areas, 4 – developing in reversed conditions occur of complementary teams of cutting, of chaps extraction and low-inclined reverse faults with tectonic breccias accompanying them, of which crumbs stayed locally combined through rust-coloured carbonate veins, 5 – being formed in conditions extraction mezofaults of normal or normalslip and of breccias accompanying them of tectonic and rust-coloured and white carbonate veins, 6 – activity very steep or threshold downthrow mayofaults of rust-coloured carbonate veins causing wide-radiant bending earlier incurred.
   The mudstone sediments generally characterize smudge structure and banded structure – of generate confluence. Locally in their area appear structures with buried all group current ripples marks, which were line of true dip.
   However in interval, where thin layers claystone, mudstone and sandstone appear opposite is disturbance bearing of still characterize. Above into thin layers light gray sandstone there is older primeval structures of characterize cross lamination and isolation structures, drop structures and buried structures.
   In thick beds sandstones appear initiator tension fissures generate of diagenesis and intracell of mudstones. In other place of sediments the Upper Cambrian are thin layers intraformation conglomerate – light gray sandstone with much intracell darkgray mudstones.