Majka, Jarosław
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nauki o Ziemi i środowisku
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Item type:Article, Access status: Open Access , Metavolcanics of Nordenskiöld Land from SW Svalbard as an example of new ocean crust(Wydawnictwa AGH, 2012) Gołuchowska, Karolina; Barker, Abigail; Manecki, Maciej; Majka, Jarosław ; Czerny, JerzyThis study concerns late Neoproterozoic metavolcanics from southwestern Svalbard in an investigation to trace the evolution of oceans plate rifting.Item type:Article, Access status: Open Access , Detrital rutile U-Pb geochronology of the Alpine convergence in the External Western Carpathians(Wydawnictwa AGH, 2023) Doliwa Zieliński, Ludwik de; Potočný, Tomáš; Bazarnik, Jakub; Kooijman, Ellen; Kośmińska, Karolina; Mazur, Stanisław; Majka, JarosławItem type:Article, Access status: Open Access , Pressure-temperature estimates on the Tjeliken eclogite from northern Jämtland, Swedish Caledonides abstract(Wydawnictwa AGH, 2012) Andersson, Barbro; Majka, Jarosław ; Klonowska, Iwona; Rosén, ÅkeEclogites are important in order to understand orogenic processes, since their presence indicates high-pressure metamorphism. In northern Jamtland, Swedish Caledonides, eclogites have been found at several places in the Seve Nappe Complex (SNC). The mountain Tjeliken in the Lower Seve Nappe is one of them. Dating relates the high-pressure metamorphism to the Late Ordovican subduction of the Baltoscandian margin during the closure of the Iapetus Ocean. In this study new P-T conditions are presented for the Tjeliken eclogite. These are based on petrological studies of an eclogite sampled on the top of the Tjeliken Mt. in summer 2010. Mineral peak assemblage consists of garnet + omphacite + phengite + quartz. Peak conditions are calculated to ca. 2.7 GPa and 700°C. These P-T conditions fall into the upper part of the quartz stability field, close to the quartz-coesite transition line. The new P-T estimates indicate a deep subduction of the Baltoscandian margin already in the Late Ordovician.Item type:Doctoral Dissertation, Access status: Open Access , Rekonstrukcja historii metamorfizmu skał grupy Isbjørnhamna z SW części Ziemi Wedel Jarlsberga na Spitsbergenie(2004-11-08) (Data obrony: 2007) Majka, Jarosław
Wydział Geologii, Geofizyki i Ochrony ŚrodowiskaThe goal of this research was to quantify the age and P-T metamorphic conditions of the polymetamorphic Isbjørnhamna Group rocks from the SW part of Wedel Jarlsberg Land on Spitsbergen. Dated monazites (U-Th-total Pb method) and zircons (U-Pb method) yielded Neoproterozoic (ca. 640Ma) age of older metamorphic event. Compilation of the results of geothermobrometry (with use of garnet-biotite geothermometer and GASP geobarometer) and the KFMASH petrogenetic grid allow to estimate that, over mentioned metamorphic event took place under upper amphibolite facies conditions. The peak conditions were described as T= ca. 660ºCi P= ca.11kbar. Additionally it was assumed that younger metamorphic event took place under temperature lower then 350ºC (on the basis of chlorite geothermometer and thermochronology) and under calm tectonic conditions.Item type:Article, Access status: Open Access , New evidence for high-pressure metamorphic rocks in Western Svalbard(Wydawnictwa AGH, 2012) Kośmińska, Karolina; Majka, Jarosław ; Krumbholz, Michael; Klonowska, Iwona; Manecki, Maciej; Czerny, JerzyDuring a field expeditions to Nordenskiöld Land and Wedel Jarlsberg Land (western Svalbard), previously unrecognised high-grade metamorphic rocks were observed. These rocks are represented by blueschists <i>sensu stricto</i> and blueschist facies metapelites.Item type:Article, Access status: Open Access , Detrital zircon U-Pb geochronology of a metasomatic calc-silicate in the Tsäkkok Lens, Scandinavian Caledonides(Wydawnictwa AGH, 2021) Barnes, Cristopher J.; Majka, Jarosław ; Bukała, Michał; Nääs, Erika; Rousku, SabineThe Tsäkkok Lens of the Seve Nappe Complex in the Scandinavian Caledonides comprises eclogite bodies hosted within metasedimentary rocks. These rocks are thought to be derived from the outermost margin of Baltica along the periphery of the Iapetus Ocean, but detrital records from the sedimentary rocks are lacking. Many metasedimentary outcrops within the lens expose both well-foliated metapelitic rocks and massive calc-silicates. The contacts between these two lithologies are irregular and are observed to trend at all angles to the high-pressure foliation in the metapelites. Where folding is present in the metapelites, the calc-silicate rocks are also locally folded. These relationships suggest metasomatism of the metapelites during the Caledonian orogenesis. Zircon U-Pb geochronology was conducted on sixty-one zircon grains from a calc-silicate sample to investigate if they recorded the metasomatic event and to assess the detrital zircon populations. Zircon grains predominantly show oscillatory zoning, sometimes with thin, homogeneous rims that have embayed contacts with the oscillatory-zoned cores. The zircon cores yielded prominent early Stenian, Calymmian, and Statherian populations with a subordinate number of Tonian grains. The zircon rims exhibit dissolution-reprecipitation of the cores or new growth and provide ages that span similar time frames, indicating overprinting of successive tectonic events. Altogether, the zircon record of the calc-silicate suggests that the Tsäkkok Lens may be correlated to Neoproterozoic basins that are preserved in allochthonous positions within the northern extents of the Caledonian Orogen.Item type:Article, Access status: Open Access , How fluids infiltrate through fractures and change metamorphic rocks - a case study from northern Spitsbergen(Wydawnictwa AGH, 2016) Faehnrich, Karol; Kośmińska, Karolina; Majka, Jarosław ; Dwornik, MaciejMetasomatism is a process leading to changes in the chemical composition of a rock or its portion. It involves introduction or removal of chemical components due to the interaction of the rock with aqueous fluid (Zharikov et al. 2007).Item type:Article, Access status: Open Access , Metamorphic conditions of the omphacite-garnet gneiss from Otrøy, Western Gneiss Region, Scandinavian Caledonides(Wydawnictwa AGH, 2016) Holmberg, Johanna; Majka, Jarosław ; Klonowska, IwonaThe Western Gneiss Region (WGR) is one of the Earth’s most studied ultra-high pressure (UHP) terranes.Item type:Article, Access status: Open Access , Metamorphic evolution of the Seve Nappe Complex in the Snasahögarna area, Swedish Caledonides(Wydawnictwa AGH, 2012) Rosén, Åke; Majka, Jarosław ; Klonowska, IwonaThe Middle Seve Nappe in the Snasahögarna mountains, western Jämtland, Sweden, is composed of high grade metamorphic rocks emplaced in far-travelled nappes. The investigation of these paragneisses, derived from the Baltica margin, can contribute information about the subduction and exhumation processes, which controlled the formation of the Seve Nappe Complex (SNC) in the Scandinavian Caledonides.Item type:Article, Access status: Open Access , Pressure-temperature estimates on blueschists from the Vestgötabreen complex (Western Svalbard)(Wydawnictwa AGH, 2014) Kośmińska, Karolina; Majka, Jarosław ; Manecki, Maciej; Kozub-Budzyń, Gabriela A.In Oscar II Land (Motalafjella area, western Svalbard), an exotic high-pressure (HP) metamorphic unit, namely the Vestgötabreen Complex (Kanat & Morris 1988) occurs. It is thrust over low-grade metasediments (e.g. Labrousse et al. 2008) of inferred Neoproterozoic age.