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Abstract

The potential of heavy minerals as a provenance tracer in Albian arenites of extra-Carpathian Poland was assessed. Studies in this area have focused on various methods based on heavy mineral chemistry that provide an effective tool for reconstructing the provenance of quartz-rich sediments. The previously suggested division of the study area into two domains with different source areas: the western domain – the Miechów area, and the eastern domain – the Lublin area, was based on geochronological (monazite and muscovite dating) and rutile mineral chemical studies. The mineral chemistry of newly examined heavy minerals supports the previously suggested division. The mineral chemistry of detrital tourmaline suggests medium-grade metamorphic rocks as the main source in both domains. Detrital garnet in the western domain shows affiliation to the Góry Sowie Massif, while garnet in the eastern domain was most probably sourced from southern/central Norway. The western domain was most probably fed from rocks of the Bohemian Massif. The main source area for the eastern domain was most probably located in the Baltic Shield. The distinct division of the study area into two domains was caused by the palaeogeography of the region in the Albian and the action of longshore currents in south-eastward and eastward directions.

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Authors and Affiliations

Jakub Kotowski
1
Danuta Olszewska-Nejbert
1
Krzysztof Nejbert
1

  1. University of Warsaw, Faculty of Geology, Żwirki i Wigury 93, 02-089 Warszawa, Poland
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Abstract

Palaeomagnetic−petrographic−structural analyses of Proterozoic–Lower Palaeozoic metamorphosed carbonates from 12 locations within Oscar II Land (Western Spitsbergen) have been carried out to determine their usefulness in palaeogeographic reconstructions for Caledonian time. Structural analyses confirm that metacarbonates record several stages of deformation: D1, D2 ductile phases related to Caledonian metamorphism and a D3 brittle phase related to Late Cretaceous–Paleogene evolution of the West Spitsbergen Fold Belt. The latter is represented by thrust faults, localized folds with strain slip cleavages and late extensional collapse. Petrographic investigations reveal that Caledonian greenschist facies metamorphism was characterized by the high activity of H 2 O−CO 2 −rich fluids which promoted extensive recrystallization and within−rock spatial reorganization of sampled meta carbonates. Microscopic, SEM and microprobe analyses exclude the existence of any primary pre−metamorphic ferromagnetic minerals (primary−related to sedimentation and or early diagenesis) and point to metamorphic 4C superstructure (Fe 7 S 8 ) pyrrhotite as the main ferromagnetic carrier in investigated rocks. This is confirmed by the three−component isothermal remanent magnetization (IRM) procedures and the results of thermal demagnetizations. In 12 sites a total number of 72 independently oriented palaeomagnetic samples were collected from which 181 specimens were drilled and thermally demagnetized. Sampled metacarbonates are weakly magnetized (NRM <0.2mA/m). The statistically significant palaeomagnetic results were achieved only from 1 of 12 investigated sites. In one site situated in the Western overturned limb of the Holmesletfjellet Syncline intermediate unblocking temperatures – “pyrrhotite related” component WTSJ5M superimposed on the S1 Caledonian schistosity was recognized (D = 100.7 ° , I = −21.4 °a 95% = 5.5 ° , k = 58.23). Coincidence of WTSJ5M with Silurian–Devonian sector of the Baltica reference path after unfolding of the syncline by the angle of 130 ° suggests synfolding origin of this direction. Further, this suggests that Holmesletfjellet Syncline originated as an open fold and has been transformed into an overturned syncline during the Late Caledonian shortening or in the Late Cretaceous–Palaeogene time.
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Authors and Affiliations

Krzysztof Michalski
Justyna Domańska-Siuda
Krzysztof Nejbert
Geoffrey Manby
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Abstract

The chevkinite group of minerals are REE,Ti-silicates increasingly recognized as widespread accessory phases in a wide range of igneous and metamorphic parageneses. Members of the group are here recorded from five localities in Poland: a two-pyroxene andesite from the Kłodzko-Złoty Stok intrusion, a trachyandesite intrusion north of the Pieniny Mountains, a rapakivi-type granite from the Krasnopol intrusion, an anorthosite from the Suwałki Anorthosite Massif, and nepheline syenite from the Ełk syenite massif. Specific members found are chevkinite-(Ce), perrierite-(Ce) and, potentially, the Al-dominant analogue of perrierite-(Ce). The case is made that chevkinite-group minerals will, through systematic investigation, be found in a wide range of Polish igneous and metamorphic rocks.

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Authors and Affiliations

Krzysztof Nejbert
Bogusław Bagiński
Jakub Kotowski
Petras Jokubauskas
Edyta Jurewicz
Ray Macdonald

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