文摘
In recent years, numerous wells have been completed in the area of the Z艂oczew Graben. Drill cores and data collected from wells have led to the recognition of an Upper Oxfordian鈥揕owermost Kimmeridgian sequence and to the construction of a 3D model of the graben with distribution of facies. Six facies types were distinguished, composed of numerous microfacies representing outer-, middle-, and inner-ramp depositional systems. The boundary of the Planula/Platynota zones is indicated by the transition from mid-inner carbonate ramp facies to mixed, carbonate鈥搒iliciclastic outer-ramp facies, as well as by appearance of debrites and calciturbidites. The distribution of gravity-flow deposits reflects the pattern of fault zones of the Z艂oczew Graben and their Late Jurassic activity. Comparison of Oxfordian鈥揕owermost Kimmeridgian facies types from central and southern Poland enabled the reconstruction of the general facies architecture in the Polish part of the northern peri-Tethyan shelf belonging to the Ma艂opolska Block. The distribution of Upper Oxfordian鈥揕owermost Kimmeridgian facies follows the block structure of the basement and was controlled by reactivation of Paleozoic tectonic blocks in the Late Jurassic. The results of studies in the Polish basin correspond well to Upper Oxfordian鈥揕ower Kimmeridgian sequences known from the ramp systems of western Europe where the basic change in deposition, from a carbonate ramp towards mixed, carbonate鈥搒iliciclastic sedimentation, was related to both North Atlantic and western European tectonics. Keywords Ramp facies and microfacies Stromatactis Synsedimentary tectonism Late Jurassic grabens Oxfordian鈥揔immeridgian Poland