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Fluid pathways within shallow-generated damage zones of strike-slip faults – evidence of map-scale faulting in a continental environment, SW Permo-Mesozoic cover of the Late Palaeozoic Holy Cross Mountains Fold Belt, Poland

Rybak-Ostrowska Barbara, Konon Andrzej, Hurai Vratislav, Bojanowski Maciej, Konon Agnieszka, Wyglądała Michał

Acta Geologica Polonica

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2020

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Vol. 70, no. 1

1--29

EN

The damage zones of exhumed strike-slip faults dissecting Jurassic carbonates in the south-western part of the Late Palaeozoic Holy Cross Mountains Fold Belt reveal second-order faults and fractures infilled with syntectonic calcite. The subsequent development of a structural pattern of microscopic fault-related structures and calcite infillings reflects the activity of strike-slip faults that began in the Late Cretaceous (Late Maastrichtian) and lasted until the early Miocene (Langhian). The fabric of the syntectonic veins provides insights into the evolution of the permeable fault-related structures that were the main pathways for fluid flow during fault activity. Microstructural study of calcite veins coupled with stable isotope and fluid inclusion data indicates that calcite precipitated primarily in a rock-buffered system related to strike-slip fault movement, and secondarily in a partly open system related to the local activity of the releasing Chmielnik stepover or the uplift of the area. The presence of meteoric fluids descending from the surface into damage zones suggest that the strike-slip faulting might have taken place in a nonmarine, continental environment.

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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.

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New data on the age of the sedimentary infill of the Orava-Nowy Targ Basin : a case study of the Bystry Stream succession (Middle/Upper Miocene, Western Carpathians)

Wysocka A., Łoziński M., Śmigielski M., Czarniecka U., Bojanowski M.

Geological Quarterly

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2018

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Vol. 62, No. 2

327--343

EN

The Neogene sedimentary succession of the Orava-Nowy Targ Basin directly overlies the Central Carpathian Paleogene Basin deposits, the Magura Unit, and the Pieniny Klippen Belt. It provides an excellent geological record that postdates the main Mesoalpine structural and geomorphological processes in the Western Carpathians. Sedimentological, petrographical and geochronological investigations have allowed forthe re-examination of pyroclastic material, zircon dating, and a discussion on the relation of the Orava-Nowy Targ Basin to the exhumation of the Tatra Massif. The Bystry Stream succession is composed of NNW-inclined freshwater siltstones, sandstones and conglomerates. A few small, sometimes discontinuous, light grey intercalations of pyroclastic deposits and a single 1-2 m thick tuffite layer occur in the upper part of the succession. The tuffite contains an admixture of organic matter and siliciclastic grains (e.g., mica), suggesting that the volcanic ash fall was accompanied by normal deposition from weak currents. Sedimentation of deposits of the Bystry Stream succession took place in terrestrial settings, predominantly on floodplains and in rivers, in the vicinity of a hilly area supplying the basin with eroded material. The age of the tuffite layer from the Bystry Stream succession was determined at 11.87 +0.12/-0.24 Ma. The source of volcanogenic material in the tuffite was probably volcanic activity in the Inner Carpathians-Pannonian region, where effusive and volcanoclastic sillca-rich rocks were being produced by extrusive and explosive activity ~12 Ma. Obtained result connects the development of the Orava-Nowy Targ Basin at ~12 Ma with the late stage of the main episode of the Tatra Massif exhumation between ~22-10 Ma.

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Constrains on stresses in isotropic homogeneous infinite half-spaces being in welded contact: 2D anti-plane and in-plane cases

Rybicki K. R., Yamashita T.

Acta Geophysica

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2008

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Vol. 56, no. 2

286-292

EN

Formulas are derived for two-dimensional problems relating stresses across a plane boundary that divides infinite homogeneous half-spaces being in welded con-tact. The calculations are made for both anti-plane and in-plane stress cases. The results obtained for the former case that involve only two stress components are useful in the analysis of fracture of strike-slip type. For the in-plane case, the relations that link stresses in one half-space with the corresponding homogeneous stresses in the other half-space are presented for arbitrarily oriented shear and normal stresses and for the center of compression (dilatation). The above relations provide a compete set of expressions that, among other things, make it possible to analyze stresses involved in faulting of deep-slip type in an inhomogeneous medium. The quantitative preliminary evaluations based on the results obtained demonstrate the great role of low rigidity media in fracture processes of all kinds within the Earth's crust.

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Strike-slip faulting in the Kielce Unit, Holy Cross Mountains, central Poland

Konon A.

Acta Geologica Polonica

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2007

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Vol. 57, no. 4

415-441

EN

Strike-slip faults and associated tectonic structures have been investigated in the Holy Cross Mountains fold belt (HCM), which is located eastwards of the Variscan foreland basin. The strike-slip fault sets form a complex network, which developed during two faulting stages: in Late Palaeozoic (I) and Maastrichtian/Palaeocene (II) times. The Late Palaeozoic fault pattern formed as a result of at least two strike-slip events: I-1 and I-2. During the first event (I-1), a N-S-striking dextral strike-slip fault set and a NNE-SSW to NE-SW-striking sinistral strike-slip fault set developed. During the next event (I-2), dextral strike slip occurred along the WNW-ESE-striking longitudinal master faults and formed a NW-SE to NNW-SSE-striking sinistral secondary strike-slip fault set. During this event, in zones north and south of the Holy Cross Fault, faultbounded blocks developed which were rotated dextrally as a result of further displacements. The strikeslip fault network was overprinted during the Maastrichtian/Palaeocene second strike-slip stage (II).