BazTech - Yadda

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Integration of seismic and well data for a 3D model of the Balkassar anticline (Potwar sub-basin, Pakistan)

Mudasir Muhammad, Wysocka Anna, Naseem Shazia

Geology, Geophysics and Environment

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2023

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Vol. 49, no. 2

123--137

EN

The Potwar sub-basin is an important hydrocarbon producing zone of the Upper Indus basin and has significant oil and gas potential. The Balkassar area is the main oil field of the Potwar sub-basin and oil is mainly produced from Eocene carbonates. The Chorgali Formation is of Eocene age and is the main reservoir rock in this area. Structurally, the Potwar sub-basin is complicated, and surface features often do not reflect subsurface structures. This is due to the presence of detachments at different levels. In such cases, it is necessary to integrate seismic data with geological information for an accurate delineation of subsurface structures. Eleven seismic profiles were interpreted to understand subsurface structural style. To correlate well data with seismic data, a synthetic seismogram has been generated. Time, velocity and depth contour maps have been prepared. A 3D model for the Chorgali Formation has been prepared which confirms that this is a four-way anticlinal structure bounded by faults. It makes this structure more favorable for hydrocarbon accumulation. Moreover, a cross section has been prepared for five wells to show that the Chorgali Formation is spreading. Based on it, to show the relationship between compressional tectonics and basement slope, a 3D structural model has been prepared. In this case study, the Balkassar anticline was interpreted as a four-way closure pop-up structure which provides a structural trap for the accumulation of hydrocarbons. This study will help us understand the accumulation of hydrocarbons in the same type of structural traps in the Potwar sub-basin and in similar kinds of basins. It is also relevant to oil exploration within Pakistan.

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Professor Piotr Roniewicz (1936-2019) : in memoriam

Wysocka Anna, Głowniak Ewa, Szulczewski Michał, Rudowski Stanisław, Giżejewski Jerzy, Karnkowski Paweł Henryk, Pinińska Joanna, Pieńkowski Grzegorz, Skompski Stanisław, Słaby Ewa, Kalinowska Anna, Sawicki Gerard

Acta Geologica Polonica

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2020

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Vol. 70, no. 4

435--452

EN

Piotr Roniewicz was born in 1936 in Warsaw, however his family roots were in Stanisławów (nowadays Ivano-Frankivsk, Ukraine). He completed his university studies at the Faculty of Geology of the University of Warsaw in 1959, gaining a Master’s Degree. He began his geological career at this Faculty already as a 4th year student. In 1981-1984 he was the Vice-Dean and later in 1984-1990 - the Dean of the Faculty. Professor Roniewicz worked there until his retirement in 2006.

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Occurrence of clastic injectites in the Oligocene strata of the Carpathians and their significance in unravelling the Paleogene and Neogene evolution of the Carpathian orogeny (Poland, Ukraine and Romania)

Jankowski Leszek, Wysocka Anna

Geological Quarterly

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2019

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Vol. 63, No. 1

106--125

EN

The irregular distribution of sand injections, traditionally termed “dykes” in the Polish geological literature, within individual Carpathian units and within individual lithofacies were observed during long-lasting field works. Injectites have been observed in the Magura Beds and in the Inoceramian Beds of the Polish and Romanian Carpathians, and in the Central Carpathian Paleogene deposits. However, they are most common in the Oligocene-Miocene Menilite Beds, where they are typical and abundant, particularly in the Skole Unit. Two clastic injectite types were distinguished: sedimentary (S-type) and tectonized (T-type). Based on the occurrence and interpretation of these injectites a new two-stage conceptual model is proposed for the Polish segment of the progressive Oligocene-Miocene Carpathian orogenic belt evolution. Type S clastic injectites are interpreted as having formed in the compressional stage, during foredeep basin migration while depositional slope changes were taking place in the Late Oligocene to Early Miocene. Type T injectites are interpreted as having formed by reactivation of S-type injectites in the last, mainly strike-slip, phases of Carpathian orogenic belt formation.

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Evidence of Late Cretaceous/Cenozoic strike-slip faulting within the late Palaeozoic Holy Cross Mts. Fold Belt, Poland: Józefka releasing stepover

Skompski Stanisław, Konon Andrzej, Wysocka Anna, Czarniecka Urszula

Acta Geologica Polonica

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2019

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Vol. 69, no. 1

89--105

EN

The aim of this study was to reconstruct the location mechanism of a Triassic sandstone wedge within folded Palaeozoic rocks. A vertically oriented Buntsandstein succession (Lower Triassic) from Józefka Quarry (Holy Cross Mountains, central Poland), steeply wedged within folded Devonian carbonates, is recognised as an effect of normal faulting within a releasing stepover. The sandstone succession, corresponding to the Zagnańsk Formation in the local lithostratigraphic scheme, is represented by two complexes, interpreted as deposits of a sand-dominated alluvial plain (older complex), and coarse-grained sands and gravels of a braided river system (younger complex). The sandstone complex was primarily formed as the lowermost part of the several kilometres thick Mesozoic cover of the Holy Cross Mountains Fold Belt (HCFB), later eroded as a result of the Late Cretaceous/Paleogene uplift of the area. Tectonic analysis of the present-day position of the deformed sandstone succession shows that it is fault-bounded by a system of strike-slip and normal faults, which we interpret as a releasing stepover. Accordingly, the formation of the stepover in the central part of the late Palaeozoic HCFB is evidence of a significant role of strike-slip faulting within this tectonic unit during Late Cretaceous/Paleogene times. The faulting was probably triggered by reactivation of the terminal Palaeozoic strike-slip fault pattern along the western border of the Teisseyre–Tornquist Zone.