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Microstructures of shear zones from selected domains of the Western Tatra Mountains

Kania M.

Geological Quarterly

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2015

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Vol. 59, No. 4

679--699

EN

The paper is focused on the meso- and microstructural characteristics of selected shearing zones in the Western Tatra Mts. The domains of crystalline rocks studied (Długi Upłaz Ridge, Rakoń Mt., Zabraty Ridge and Zabrať Pass, Wołowiec Mt., Trzydniowiański Mt., Czubik Mt. and Jarząbczy Mt.) show evidences of heterogeneous shearing with development of shear zones. Four types of shear zones were distinguished: (1) ductile shear zones in gneisses, (2) brittle-ductile complex shear zones, (3) gneisses with clear later brittle deformation; (4) leucogranites, produced by anatexis with later brittle deformation. The development of these shear zones is characterised by occurrences of various types of fault rocks: cataclasites, S-C cataclasites and mylonites. The different shearing-related rocks and structures are interpreted as an effect of protolith diversity and strain partitioning. Shape-preferred orientation is an important structural feature of all the shearing-related rocks. Kinematic analyses revealed generally a southward sense of shearing documented by structures related to brittle conditions and northwards sense of shearing recognised in ductily sheared crystalline rocks. The time relationships between different shear zone types are discussed, leading to the conclusions that the 1st type of shear zone is pure Variscan, the 2nd type is Variscan with Alpine brittle deformation, and the 3rd and 4th types are mainly Alpine brittle deformations of Variscan syntectonic anatectic leucogranites.

2

Aptian foraminiferal stratigraphy and Nannoconus assemblages from the Kopka section (Western Tatra Mountains, Poland)

Pszczółkowski A.

Annales Societatis Geologorum Poloniae

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2015

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Vol. 85, No. 1

123--138

EN

In the Kopka section (Dolina Kościeliska valley, Western Tatra Mountains), the upper part of the Kościeliska Marl Formation consists of biomicrites with marly interbeds. These deposits, 76 m thick, are assigned to the Praehedbergella excelsa and Leupoldina cabri zones, of Aptian age. The taxa identified belong mainly to the genera Praehedbergella Gorbachik and Moullade, 1973, Globigerinelloides Cushman and Ten Dam, 1948 (emended by Longoria 1974 and Verga and Premoli Silva, 2003a) and Gorbachikella Banner and Desai, 1988. Nineteen Nannoconus taxa were identified during an SEM study of 34 samples. The occurrence of N. vocontiensis in the higher part of the section allows the nannoconid assemblages in the upper part of the section to be distinguished from those in the lower part. Four Nannoconus assemblages were recognized in these limestones: (1) Nannoconus bucheri-N. steinmannii, (2) N. truitti frequens, (3) N. vocontiensis and (4) N. aff. regularis. The wide-canal Nannoconus specimens are more frequent than the narrow-canal ones in the limestones of earliest Aptian age (Praehedbergella excelsa Zone), but the wide-canal forms predominate consistently in the upper part of the section, still within the L. cabri Zone.

3

Stratigraphic position of alkaline volcanic rocks in the autochthonous cover of the High-Tatric Unit (Western Tatra Mts., Central Western Carpathians, Slovakia)

Madzin J., Sýkora M., Soták J.

Geological Quarterly

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2014

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Vol. 58, No. 1

163--180

EN

Biostratigraphic investigations of carbonate strata that sandwich volcanic rocks and studies of the volcanic rocks were made along five composite lithological sections across the Upper Jurassic-Lower Cretaceous carbonate rocks of autochthonous cover of the High-Tatric Unit in the Osobitá peak area of the Western Tatra Mts. A carbonate microbreccia that consists almost exclusively of limestone clasts containing calpionellids occurs immediately below the volcanics. The youngest identified microfossil Calpionella elliptica Cadisch in the individual limestone clasts showed the age of breccia formation to be younger than late Early-early Middle Berriasian. The volcanic rocks are overlain by the Osobitá Limestone Formation, which in the lowermost horizons consists of a few metres thick crinoidal limestone containing the foraminifers Meandrospira favrei (Charollais, Brönnimann & Zaninetti), Sabaudia minuta Hofker and Montsalevia salevensis (Charollais, Brönnimann & Zaninetti) indicating a Late Valanginian-Early Hauterivian age. The biostratigraphical and sedimentological data obtained show that volcanism took place in several phases. Less intense phases of volcanism are recorded as thin tuffitic laminae within the upper parts of the Tithonian-early Mid Berriasian Sobótka Limestone Member and as fragments of volcanic rock in the carbonate breccia. The main phase(s) of volcanism took place during the Late Berriasian-?Early Valanginian.

4

Microfabric diversity and grain shape analysis of fault rocks from the selected areas of the Western Tatra Mountains

Kania M.

Geological Quarterly

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2014

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Vol. 58, No. 1

3--18

EN

Fault rocks in brittle and brittle-ductile shear zones played a key role in the evolution of the Western Tatra Mountains crystal- line rocks (Poland-Slovakia). Microfabrics of these rocks, including grain shape analyses, were investigated in the six areas of the Western Tatra Mountains. Based on studies of thin sections, 14 types of fault rock microfabric are distinguished, ac- cording to the following criteria: (a) the presence and abundance levels of a cataclastic matrix and (b) the presence and form of a preferred orientation features. General tendencies observed in these areas indicate southwards increasing non-coaxial deformation as well as the domination of ultracataclasites or ultramylonites to phyllonites in areas with negative relief (e.g., sedlo Zabrat’ Pass, Dziurawa Przełęcz Pass). A model of shear zone evo l u tion embracl ng foll owl ng three stages is pro- posed: (1) deformation partitioning and block-controlled cataclastic flow, (2) matrix-controlled cataclastic flow, (3) selective leaching and deposition of silica, leading to the formation of softened and hardened deformation domains respectively. These microstructural observations were supported by statistical analyses of the grain shape indicators (compactness, isometry, ellipticity, solidity, convexity). Two trends of relationships between compactness and convexity were noted: the first, horizontal on the correlation diagrams, was interpreted as an effect of rapid cataclasis and then sericitization, the sec- ond, with a strongly negative correlation coefficient, was considered as an effect of long-term cataclastic flow. The different microfabric data and microstructural interpretations described in this paper are consistent with a new model of the tectonic history of the Western Tatra Mountains evolution, with an important role for a non-coaxial deformation during Alpine orogeny in brittle and brittle-ductile conditions.

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The Tithonian-earliest Berriasian Nannoconus zones in selected sections of the Pieniny Klippen Belt and the Western Tatra Mountains (southern Poland)

Pszczółkowski A.

Studia Geologica Polonica

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2009

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Vol. 132

7-38

EN

In comparison with the Spanish sections, first appearance (FAD) of the Tithonian Nannoconus species is recorded earlier in the Pieniny Klippen Belt and the Western Tatra Mountains (Western Carpathians). The Early Tithonian Nannoconus compressus Zone correlates with the uppermost part of the "Pulla-Tithonica" Zone and the lower part of the Malmica Zone. The N. infans Zone corresponds to the upper part of the Malmica Zone and the lower part of the Chitinoidella Zone (Dobeni Subzone) including the lowermost interval of the Boneti Subzone. The N. wintereri Zone is equivalent to the uppermost part of the Chitinoidella Zone, entire Crassicollaria Zone, and the basal interval of the Berriasian Alpina Subzone. In the Kryta Valley section (Tatra Mts), the Infans/ Wintereri zonal boundary is located within the Boneti Subzone and is correlated with the lower part of the CM20n magnetozone. Specimens referred to Nannoconus sp. A occur in the studied sections; these specimens differ from the published descriptions of all previously established Tithonian species. In the Lower Tithonian limestones nannoconids are scarce being more numerous in the lower interval of the N. wintereri Zone. Increase in abundance of the genus Nannoconus correlates with the Mid- to Late Tithonian Nannofossil Calcification Event (NCE) reported from the Central Atlantic Ocean.

6

Profile wiertnicze osadów czwartorzędowych na Ornaku oraz ich znaczenie w badaniach nad ostatnim zlodowaceniem w Tatrach Zachodnich

Kenig K., Lindner L.

Przegląd Geologiczny

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2001

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Vol. 49 nr 12

1180-1185

PL

Przedstawiono wyniki badań litogenetycznych osadów czwartorzędowych pobranych przy pomocy trzech, pierwszych na obszarze Tatr, otworów wiertniczych zlokalizowanych na Polanie Ornak w górnej części Doliny Kościeliskiej. Z uzyskanych tą drogą materiałów wynika, że zachowane są tu trzy warstwy (poziomy) gliny morenowej, przedzielone nieglacjalnymi osadami różnej genezy. Na podstawie charakterystyki granulometrycznej oraz mineralogiczno-petrograficznej wykazano, że wymienione warstwy gliny morenowej mogą reprezentować trzy fazowe nasunięcia lodowców, a osady dzielące mogą reprezentować dwie interfazy w obrębie stadiału Białki ostatniego (würm, vistulian) zlodowacenia tatrzańskiego.

EN

The this paper presents the results of lithogenetic investigations of Quaternary deposits discovered for the first time bv three boreholes located at the Polana Ornak in the upper part of the Kościeliska Valley. Three till horizons separated by non-glacial deposits of different origin were recognized in the material obtained. Granulometric and mineralogical-petrographic analysis suggests that these till horizons may be ascribed to three phases of glacier advance, whereas the interbeds to two interphases within the Białka stadia! of the last (Wiirm, Vistulian) glaciation in the Tatra region