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Tytuł:
Unraveling the collisional history of the Western Carpathians through deep geophysical sounding
Autorzy:
Soni, Tanishka
Schiffer, Chrystian
Mazur, Stanisław
Tematy:
Carpathians
Tethys
terranes
Pokaż więcej
Data publikacji:
2023
Powiązania:
https://bibliotekanauki.pl/articles/24202097.pdf  Link otwiera się w nowym oknie
Źródło:
Geotourism / Geoturystyka; 2023, 1-2 (72-73); 65--66
1731-0830
Pojawia się w:
Geotourism / Geoturystyka
Opis:
The ALpine-CArpathian-PAnnonian (ALCAPA) block is one of the terranes involved in the Alpine-Tethys suture along with the North European Plate. In the Western Carpathians, this suture is supposed to be represented by the Pieniny Klippen Belt (PKB) which is a few kilometres wide and about 600 km long unit between the Outer Western Carpathians (OWC) and Central Western Carpathians (CWC) (Plašienka et al., 1997; Schmid et al., 2008). Unlike the Neotethian suture in the Western Carpathians, the PKB does not show the typical characteristics of a suture. The PKB is a sub-vertical unit with mainly shallow marine limestone and flysch deposits in a conspicuous “blockin-matrix” structure (Plašienka et al., 1997). The presence of “exotic” sediments in the PKB and the southernmost units of the OWC along with their shallow marine deposition environment led to the theory proposing the presence of a continental sliver called the Czorsztyn Ridge in the Alpine Tethys, dividing it into two oceanic/marine basins: the Magura Ocean to the north and the Vahic Ocean to the south (Plašienka, 2018). This controversial continental fragment possibly forming the basement for PKB successions, and its structural relationship with the adjoining OWC and CWC units, make it the main target of this project. The objective is to find evidence of the presence of this continental block, the Czorsztyn Ridge, which may have subducted along with the Vahic oceanic lithosphere underneath the CWC (Schmid et al., 2008). A passive seismic experiment will provide insight into the deep lithospheric structure across the PKP, testing the presence of a tectonic suture along with relaminated remnants of the Czorsztyn Ridge, and potential remnants of subducted or underthrusted lithosphere. Eighteen broadband stations have been deployed in a ~N-S transect (Fig. 1a) under the umbrella of the AdriaArray initiative, cutting across the PKB and Neotethian Meliata suture to the south. The data obtained during up to three years will complement 10 other permanent and temporary broadband stations, forming an approximate 370 km long profile and will be used to perform receiver function analysis and build structural and velocity models of the lithosphere (i.e., Schiffer, 2014; Schiffer et al., 2023) beneath the Western Carpathians. The horizontal extent of the imaging is shown in Figure 1b.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Metamorphic conditions of the omphacite-garnet gneiss from Otrøy, Western Gneiss Region, Scandinavian Caledonides
Autorzy:
Holmberg, J.
Majka, J.
Klonowska, I.
Tematy:
crustal rock
terranes
continental rock
Pokaż więcej
Data publikacji:
2016
Powiązania:
https://bibliotekanauki.pl/articles/184242.pdf  Link otwiera się w nowym oknie
Źródło:
Geology, Geophysics and Environment; 2016, 42, 1; 75
2299-8004
2353-0790
Pojawia się w:
Geology, Geophysics and Environment
Opis:
The Western Gneiss Region (WGR) is one of the Earth’s most studied ultra-high pressure (UHP) terranes. It consists of continental crustal rocks that host e.g. coesite-bearing eclogites and diamond-bearing garnet-pyroxenites. These self-evident high pressure lithologies naturally attract most of the attention, whereas their host rocks are not studied in much detail. In this study we examined, eclogite- and peridotite-hosting, garnet-omphacite gneisses from the island of Otrøy situated in the WGR (Norway, Scandinavian Caledonides), to deliver pressure-temperature conditions of their formation. High pressure mineral assemblage including e.g. omphacite and phengite together with assumed pseudomorphs after coesite located in omphacite and garnet suggest formation of the studied rocks under ultrahigh pressure metamorphic (UHP) conditions. However, geothermobarometry based on (a) the garnet-clinopyroxene Fe-Mg exchange reaction and (Ravna 2000), and (b) the net-transfer reaction 6 diopside + 3 muscovite = 3 celadonite + 2 grossular + pyrope (Ravna & Terry 2004) yielded pressure-temperature conditions of c. 880°C and 2.2 GPa, characteristic for just high pressure metamorphism, but not in the stability field of coesite (hence not UHP conditions). It might be an effect of partial re-equilibration of the mineral system used for geothermobarometry. Such re-equilibration could have happened during the decompression stage, which followed the metamorphic peak. Therefore alternative pressure-temperature estimates using e.g. phase equilibrium thermodynamic modeling or Raman band shift based geothermobarometry are needed to cross-check the results obtained using the conventional technique. Nevertheless, it is already evident that the Otrøy gneisses were formed due to the deep subduction of continental crust during the Scandian collision between the continents Baltica and Laurentia that resulted in the final closure of the Iapetus Ocean in the early Devonian.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Pomeranian Caledonides (NW Poland), fifty years of controversies: a review and a new concept
Autorzy:
Dadlez, R.
Tematy:
Caledonides
Pomeranian Caledonides
Rügen
tectonics
terranes
Pokaż więcej
Data publikacji:
2000
Powiązania:
https://bibliotekanauki.pl/articles/2059454.pdf  Link otwiera się w nowym oknie
Źródło:
Geological Quarterly; 2000, 44, 3; 221-236
1641-7291
Pojawia się w:
Geological Quarterly
Opis:
The results of a half-century investigations of the Pomerania-Rügen Caledonides are reviewed. Fifty years ago there were two rival hypotheses based exclusively on analyses of gravity and magnetic data. One of them assumed the presence of the so-called Circum-Fennosarmatian Caledonides, the second one claimed that the Precambrian craton of the eastern Europe extends far to the west reaching northern Germany and Pomerania. As time passed, more new facts from boreholes and seismic refraction and reflection studies accumulated. New hypotheses appeared, namely the concepts of an aulacogen and a major strike-slip fault, now merely of a historical importance. In spite of the new data the principal dilemma remains the same until present. Some investigators believe that the East European Craton (Baltica) extends far to the south-west reaching the Elbe-Odra Line, others assume the presence of the Caledonian deformations in Rügen and Pomerania which are regarded - according to modern concepts - as a manifestation of terrane tectonics. The latter group of hypotheses is supplemented by the author with the model of proximal terranes detached from the craton margin farther to the south-east and then re-accreted. The hypothesis is based on an analysis of differences in crustal structure in northern Germany and western Poland, and on the concept of a counter-clockwise rotation of Baltica during the Ordovician, proved by palaeomagnetic data.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Variscan Orogen in Poland
Autorzy:
Mazur, S.
Aleksandrowski, P.
Kryza, R.
Oberc-Dziedzic, T.
Tematy:
Bohemian Massif
Sudetes
Palaeozoic
terranes
metamorphism
magmatism
Pokaż więcej
Data publikacji:
2006
Powiązania:
https://bibliotekanauki.pl/articles/2058949.pdf  Link otwiera się w nowym oknie
Źródło:
Geological Quarterly; 2006, 50, 1; 89-118
1641-7291
Pojawia się w:
Geological Quarterly
Opis:
The structure and evolution of the Polish part of the Variscan Orogenic Belt is reviewed, based on published data and interpretations. The Sudetic segment of the Variscides, together with adjacent areas, experienced multi-stage accretion during successive collisional events that followed the closure of different segments of the Rheic Ocean. In SW Poland, Variscan tectono-stratigraphic units are tectonically juxtaposed and often bear record of contrasting exhumation/cooling paths, constrained by palaeontological and geochronological data. This points to the collage-type tectonics of this area. A three-partite subdivision of the Sudetes is proposed that reflects timing differences in deformation and exhumation of the respective segments. The Central,West and East Sudetes were deformed and amalgamated during the Middle/Late Devonian, at the turn from the Devonian to Carboniferous and during Early Carboniferous times, respectively. Problems in extending the classical tectono-stratigraphic zonation of the Variscides into the Sudetes are discussed and attributed to activity along Late Palaeozoic strike-slip faults and shear zones, disrupting and dispersing the initially more simply distributed tectono-stratigraphic units into the present-day structural mosaic. Relationships between the Variscan Externides and the foreland basin are explored. Sediments of the foreland basin locally onlap the external fold-and-thrust belt that had undergone an earliest Carboniferous partial tectono-thermal overprint. During the Late Carboniferous, the SW part of the foreland basin was heavily affected by thrusting and folding and incorporated into the Externides. DuringWestphalian C to Early Permian times, localized folding and thrusting affected the distal parts of the foreland basin, probably in response to dextral transpressional movements along NW–SE trending basement faults.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Jurassic succession at Lisadele Lake (Tulsequah map area, British Columbia, Canada) and its bearing on the tectonic evolution of the Stikine terrane
Autorzy:
Shirmohammad, F.
Smith, P.
Anderson, R.
McNicoll, V.
Tematy:
ammonites
chronology
Stikinia
terranes
Middle Jurassic
Lower Jurassic
Pokaż więcej
Data publikacji:
2011
Powiązania:
https://bibliotekanauki.pl/articles/2061004.pdf  Link otwiera się w nowym oknie
Źródło:
Volumina Jurassica; 2011, 9, 1; 43-60
1896-7876
1731-3708
Pojawia się w:
Volumina Jurassica
Opis:
Jurassic rocks in the central Tulsequah map area include conglomerates and interbedded fossiliferous finer clastics of the Takwahoni Formation (Laberge Group) which unconformably overlie Triassic rocks. Ammonite collections document the Pliensbachian, Toarcian and Bajocian stages. We refine the age and provenance of episodes of coarse clastic input and confirm the progressive change of dominant clast lithology from reworked sedimentary rocks above the Triassic-Jurassic unconformity to volcanic, plutonic and then metamorphic clasts in the Upper Toarcian. The uppermost coarse clastic unit is a Bajocian chert-pebble conglomerate which, along with the immediately underlying black mudstone, we include in the Bowser Lake Group. Together with regional correlations, this confirms that the age of the basal part of the Bowser Lake Group is diachronous, younging southwards into Stikinia. Sandstone petrofacies trends and changes in conglomerate clast composition indicate arc uplift and dissection followed by Middle Jurassic orogen recycling. The isotopic ages of detrital zircons and granite clasts compared with the biochronologically constrained ages of the enclosing strata suggests that processes of intrusion, arc uplift, unroofing, and clastic deposition during the Early Jurassic occurred over intervals of significantly less than five million years.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Jeszcze raz o terranach w Polsce i ich wędrówce
Once again about terranes in Poland and their wandering
Autorzy:
Nawrocki, J.
Tematy:
paleogeografia
ewolucja tektoniczna
terrany
Polska
paleogeography
tectonic evolution
terranes
Polska
Pokaż więcej
Data publikacji:
2015
Powiązania:
https://bibliotekanauki.pl/articles/2075320.pdf  Link otwiera się w nowym oknie
Źródło:
Przegląd Geologiczny; 2015, 63, 11; 1272--1283
0033-2151
Pojawia się w:
Przegląd Geologiczny
Opis:
Results of interdisciplinary studies conducted until now lead to a univocal conclusion that Poland should be regarded as a collage of terranes of different ages and provenances of the basement, and different amalgamation and accretion scenarios. Geophysical and tectonic-structural investigations have allowed defining, with different accuracies, the boundaries between particular terranes. Terranes located in the area of Paleozoic platform were subjected to two or three phases of mobility. The first phase of transcontinental scale was manifested by large-scale tectonic transport during rebuilding of global paleogeography. The second mobility phase of regional scaleaffected the Teisseyre-Tornquist terrane assemblage and was linked with the Laurentia and Avalonia collision. This process put in motion the escape tectonics in the earliest Devonian. As its result, some of terranes were reshuffled during their tectonic transportation in the SE direction. The third, Carboniferous phase of mobility of only local scale was related mainly to the dextral strike-slip tectonic activity. Unfortunately, in the case of several tectonostratigraphic units, an answer to the questions concerning their initial location and way of migration is still impossible. It is valid also in the case of the Teisseyre-Tornquist terrane assemblage, now located to the SE of the Moravia and Grójec fault zones. This reticence in geological diagnosis occurs in spite of generally good access to the rocks of the Brunovistulia and Małopolska terranes that could contain substantial information about the earliest stages of evolution of these units. In order to eliminate numerous gaps in our knowledge about the Polish terranes a new interdisciplinary scientific program should be developed.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ordovician through earliest Devonian development of the Holy Cross Mts. (Poland): constraints from subsidence analysis and thermal maturity data
Autorzy:
Narkiewicz, M.
Tematy:
Trans-European Suture Zone
Holy Cross Mountains
tectonic subsidence
thermal history
terranes
Pokaż więcej
Data publikacji:
2002
Powiązania:
https://bibliotekanauki.pl/articles/2059907.pdf  Link otwiera się w nowym oknie
Źródło:
Geological Quarterly; 2002, 46, 3; 255-266
1641-7291
Pojawia się w:
Geological Quarterly
Opis:
The Łysogóry Block (ŁB) exposed in the northern Holy Cross Mts. (HCMts.) reveals subsidence and thermal development consistent with the pattern observed in adjoining East European Craton (EEC) areas. This evidence, in addition to previously reported similarities in sedimentation and deep crustal structure, contradicts the Pożaryski's hypothesis that the Łysogóry Block represents a terrane within the Caledonian orogen. This area is here interpreted as the part of a Late Silurian foredeep basin which developed on the Baltica margin in response to terminal phases of collision with Eastern Avalonia. The development of the continuous Late Silurian foredeep basin along the EEC margin from the Peri-Tornquist Basin in the north-west to the present northern HCMts. implies that the North German-Polish Caledonides orogen had its NE continuation near the present Holy Cross area. The southern HCMts. comprise the northern margin of the Małopolska Massif (MM). The Ordovician-Silurian subsidence development of this area, its thermal history and crustal structure point to a stable cratonic setting. Existing similarities in sedimentary succession (mostly Ordovician and Lower Silurian) as well as clearly Baltic palaeobiogeographic affinities indicate a close spatial connection between the MM and Baltica during the analysed time interval. The juxtaposition of the MM against the ŁB area can be explained assuming that the MM is a part of Baltica detached from its margin due to right-lateral strike-slip after late Ludlow and before Emsian time.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Detrital zircon analysis of metasedimentary rocks of the Staré Město Belt, Sudetes : implications for the provenance and evolution of the eastern margin of the Saxothuringian terrane, NE Bohemian Massif
Autorzy:
Śliwiński, Marek
Jastrzębski, Mirosław
Sláma, Jiří
Tematy:
detrital zircon age spectra
provenance
Variscan terranes
Staré Mìsto Belt
Bohemian Massif
Pokaż więcej
Data publikacji:
2022
Powiązania:
https://bibliotekanauki.pl/articles/2187195.pdf  Link otwiera się w nowym oknie
Źródło:
Geological Quarterly; 2022, 66, 2; art. no. 21
1641-7291
Pojawia się w:
Geological Quarterly
Opis:
The Staré Město Belt (SMB) in the Central Sudetes forms a Variscan tectonic boundary zone that is located between the Saxothuringian and Brunovistulian terranes of the Bohemian Massif. The three thrust-bounded upper, middle and lower lithotectonic units of the SMB are composed of metasedimentary and Late Cambrian metavolcanic rocks. A new LA-ICP-MS zircon geochronology supported by zircon typology studies of the mica schists of the upper unit and the migmatitic paragneisses of the middle unit provides new insights into the provenance and evolution of the SMB. Our new data were obtained from metasedimentary rocks and compared to the previously published zircon ages of the SMB metavolcanic rocks. The results indicate that the metasedimentary and bimodal metavolcanic rocks in the separate lithotectonic units of the SMB originally formed Late Cambrian volcano-sedimentary successions. The source areas of the sedimentary basins studied were dominated by Neoproterozoic and Paleoproterozoic crystalline rocks that were presumably located near the West African Craton of Gondwana. A comparison of the detrital age spectra obtained with those previously published from the region indicates a strong association of the entire SMB with the Saxothuringian terrane of the Bohemian Massif. During partial melting of the metasedimentary rocks of the middle unit of the SMB, Cambrian and older zircon grains were affected by solid-state transformations that caused partial resetting of the U-Pb dates, changes in internal zircon textures and reductions in Th/U ratios.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Skorupa oceaniczna i ofiolity w Sudetach Środkowych w świetle rozważań tektonicznych
Oceanic crust and ophiolites in the Central Sudetes in the light of tectonic considerations
Autorzy:
Cymerman, Z.
Tematy:
ofiolity
terrany
Góry Sowie
kompleks metamorficzny
orogeneza
geofizyka
Sudety
ophiolites
terranes
metamorphic complex
orogeny
geophysics
Sudetes
Pokaż więcej
Data publikacji:
2017
Powiązania:
https://bibliotekanauki.pl/articles/2075680.pdf  Link otwiera się w nowym oknie
Źródło:
Przegląd Geologiczny; 2017, 65, 12; 1540--1547
0033-2151
Pojawia się w:
Przegląd Geologiczny
Opis:
Znosko (1981a, b) first stated the important fact that the Sowie Góry "nappe” was lying on the rocks of the Middle Sudetic Ophiolite Complex. In the light of current geophysical and tectonic data, it still remains up-to-date. Both those articles have initiated a new look at the Paleozoic tectonic evolution of the Sudetes and its surroundings. This article presents an analysis ofpotential boundaries oflithostratigraphic terranes in the Sudetes and the Fore-Sudetic Block, confirmed by the waveforms of gravity horizontal gradients. Gravimetric modelling along the selected profile 3 makes it possible to present the subsurface geological structure. Metamorphic rocks of the Sowie Góry complex can probably reach a depth of almost 5 km on the Fore-Sudetic Block. Below them are mafic and ultramafic rocks, reaching a depth of up to 12 km, which belong to the Middle-Sudetic Ophiolite Complex. The kinematic data from the Sowie Góry metamorphic complex indicate displacement with the top-to-SW and to-S, as in the Middle-Sudetic Ophiolite Complex. Controversy over the origin and the geotectonic environment of the Early Ordovician protolith of the Sowie Góry gneisses, which are probably a magma product of arc-type magmatism formed above a subduction zone of the Tornquist Ocean. The Sowie Góry terrane can be considered as a relic of the Early Ordovician Paleozoic magma arc (the so-called peri-Baltic arc). The Sowie Góry terrane was moved towards the SW and S on obducted dismembered fragments of ophiolite sequences after closing the Rheic Ocean during the Eo-Variscan orogenesis.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zarys budowy i ewolucji tektonicznej waryscyjskiej struktury Sudetów
Outline structure and tectonic evolution of the Variscan Sudetes
Autorzy:
Mazur, S.
Aleksandrowski, P.
Szczepiński, J.
Tematy:
Masyw Czeski
paleozoik
tektonostratygraficzne terrany
tektonika
deformacja
uskoki przesuwcze/normalne
Bohemian Massif
Palaeozoic
tectonostratigraphic terranes
tectonics
deformation
strike-slip faults
Pokaż więcej
Data publikacji:
2010
Powiązania:
https://bibliotekanauki.pl/articles/2074758.pdf  Link otwiera się w nowym oknie
Źródło:
Przegląd Geologiczny; 2010, 58, 2; 133-145
0033-2151
Pojawia się w:
Przegląd Geologiczny
Opis:
The structure and evolution of the Polish part of the Sudetes is reviewed on the basis of published data and interpretations. The Sudetic segment of the Variscides and its adjacent areas were subjected to multi-stage accretion during successive collisional events that followed closure of different segments of the Rheic Ocean. Early Variscan deformations culminated in the Late Devonian due to docking of the Armorican terrane assemblage to the southern margin of Laurussia. The Variscan orogenic activity continued into the Carboniferous and was associated with a new collision and intense folding and thrusting, followed by abundant magmatism, gravitational collapse and resulting exhumation of deeply buried metamorphic complexes as well as by inversion of the foreland basin. In the Sudetes, Variscan tectonostratigraphic units are tectonically juxtaposed and often bear record of contrasting exhumation/cooling paths, constrained by palaeontological and geochronological data. This provides evidence for the presence of allochthonous units, of partly cryptic tectonic sutures and an of overall collage-type tectonics of that area. The main lithostratigraphical components distinguished within the Sudetes are: 1) non-metamorphic to metamorphosed Neoproterozoic igneous suites accompanied by volcano-sedimentary successions, 2) Late Cambrian granitoids gneissified during the Variscan orogeny, 3) variously metamorphosed Ordovician through Devonian volcano-sedimentary successions deposited in pre-orogenic extensional basins, 4) dismembered fragments of a Late Silurian ophiolitic complex, 5) Devonian to Lower Carboniferous sedimentary successions of a passive continental margin, 6) Carboniferous granitoids, and 7) clastic sediments of Devonian and/or Early Carboniferous intramontane basins. All these components are assembled to form part of the internal Variscan orogenic zone largely exposed within the area of the Bohemian Massif. A three-partite subdivision of the Sudetes proposed here reflects different timing of deformation and exhumation of the respective segments. The Central, West and East Sudetes were deformed and amalgamated during the Middle/Late Devonian, at the turn of the Devonian and Carboniferous and during Early Carboniferous, respectively. Problems in extending the classical tectonostratigraphic zonation of the Variscides into the Sudetes are explained as due to activity of Late Palaeozoic strike-slip faults and shear zones, disrupting and dispersing the initially more simply distributed tectonostratigraphic units into the present-day structural mosaic.
Dostawca treści:
Biblioteka Nauki
Artykuł

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