On the palaeomagnetic age of the Zalas laccolith : (southern Poland)

• Autorzy: Nawrocki J. , Polechońska O. , Lewandowska A. , Werner T.
• Języki publikacji: EN

Abstrakty

EN

An age estimation for the Zalas laccolith (Kraków area, South Poland) using the palaeomagnetic method is presented. 29 hand samples were taken from the rhyodacites and neighbouring Visean sediments cropping out in three localities. Two components of magnetization were isolated in the volcanic rocks and Visean sediments. The "A" component, common to the greenish rhyodacites and Visean sediments from Orlej, is carried by magnetite and is regarded as primary. Comparison of the mean inclination of this component with the expected (reference) stable European inclinations leads to the conclusion that the Zalas laccolith was emplaced about 280 Ma ago. The second component, "B", characteristic of the reddish rhyodacites, is carried by hematite and was recorded during the Late Permian (c. 260 Ma) metasomatic alterations of these rocks.The palaeomagnetic poles calculated for the "A" component show a distinct departure from the Permian segment of the Baltic apparent polar wander path (APWP) due to anticlockwise block rotations of the rocks studied that were most probably connected with the Early Permian sinistral transtensional tectonic regime in Central Europe.

Słowa kluczowe

EN

paleomagnetism; Permian; rhyodacites; southern Poland; Zalas

• Wydawca: Faculty of Geology of the University of Warsaw ; Komitet Nauk Geologicznych PAN
• Czasopismo: Acta Geologica Polonica
• Rocznik: 2005
• Tom: Vol. 55, no. 3
• Strony: 229--236
• Opis fizyczny: Bibliogr. 21 poz., rys., wykr.,

Twórcy

autor

Nawrocki J.

• Paleomagnetic Laboratory, Polish Geological Institute, Rakowiecka 4, PL-00-975 Warszawa, Poland

autor

Polechońska O.

• Paleomagnetic Laboratory, Polish Geological Institute, Rakowiecka 4, PL-00-975 Warszawa, Poland

autor

Lewandowska A.

• Institute of Geological Sicences, Jagiellonian University, Oleandry 2a, PL-30-063 Kraków, Poland

autor

Werner T.

• Institute of Geophysics, Polish Academy of Sciences, Ks. Janusza 64, PL-01-452 Warszawa, Poland

Bibliografia

• BIRKENMAJER, K. & NAIRN, A.E.M. 1964. Paleomagnetic studies of Polish rocks. I. The Permian igneous rocks of the Kraków District and some results from the Holy Cross Mountains. Annales de la Societe Geologique de Pologne, 34, 225-244.
• DŻUŁYŃSKI, S. 1955. O formie geologicznej występowania porfirów zalaskich. Biuletyn Instytutu Geologicznego, 97, 9-38.
• ENKIN, R.J. & WATSON, G.S. 1996. Statistical analysis of paleomagnetic inclination data. Geophysical Journal International, 126, 495-504.
• GRABOWSKI, J., NARKIEWICZ, M., NAWROCKI, J. & WAKSMUNDZKA, M.I. 2002. Permian remagnetization of the Devonian carbonates in southern Poland – probable link with diagenetic processes. Przegląd Geologiczny, 50, 78-86. [In Polish with English summary]
• HARAŃCZYK, C. 1989. Rozwój wulkanizmu krakowskiego. In: Przewodnik 60 Zjazdu Polskiego Towarzystwa Geologicznego w Krakowie, pp. 51-58. Wydawnictwo Geologiczne AGH; Kraków.
• HARAŃCZYK, C. & CHOCYK, M. 1989. Melafirowe potoki Regulic. In: Przewodnik 60 Zjazdu Polskiego Towarzystwa Geologicznego w Krakowie, pp. 58-60. Wydawnictwo Geologiczne AGH; Kraków.
• IRVING, E. 1964. Paleomagnetism and its application to geological and geophysical problems, 485 pp. Wiley & Sons; New York – London – Sydney.
• JELEŃSKA, M., KÀDZIAŁKO-HOFMOKL & M., ŻELAŹNIEWICZ, A. 2003. The Devonian-Permian APWP for the West Sudetes, Poland. Studia Geophysica et Geodetica, 47, 419-433.
• KOZŁOWSKI, S. 1955. Intruzje porfirowe w grzbiecie dębnickim. Biuletyn Instytutu Geologicznego, 97, 38-102.
• KIRSCHVINK, J.L. 1980. The least square line and plane and the analysis of paleomagnetic data. Geophysical Journal of Royal Astronomical Society, 62, 699-718.
• LEWANDOWSKA, A. & ROSPONDEK, M. 2003. Geochemistry of Volcanics of the Zalas Area near Kraków, South Poland. Polskie Towarzystwo Mineralogiczne – Prace specjalne, 23, 119-121.
• LEWANDOWSKI, M., WERNER, T. & NOWOŻYŃSKI, K. 1997. PCA – a package of Fortran programs for paleomagnetic data analysis. Institute of Geophysics, Polish Academy of Sciences, manuscript, p. 18.
• LOWRIE, W. 1990. Identification of ferromagnetic minerals in a rock by coercivity and unblocking temperature properties. Geophysical Research Letters, 17, 159-162.
• MATTERN, F. 2001. Permo-Silesian movements between Baltica and Western Europe: tectonics and ‘basin families’. Terra Nova, 13, 368-375.
• NAWROCKI, J. 1993. The Devonian-Carboniferous platform paleomagnetic directions from the Silesian-Cracow area and their importance for Variscan paleotectonic reconstructions. Geological Quarterly, 37, 397-430.
• — 1998. Paleomagnetic data and tectonic regime during Permian sedimentation in Sudety Mountains. Przegląd Geologiczny, 46, 1023-1027. [In Polish with English summary]
• PIŁAT, T. 1957. Otoczaki porfirowe z łupków górnego wizenu z okolic Zalasu (okolice Krakowa). Biuletyn Instytutu Geologicznego, 115, 167-185.
• SKOWROŃSKI, A. 1974. Oznaczanie wieku bezwzględnego tzw. porfirów z Zalasu metodą śladów rozszczepienia jąder atomów uranu. Sprawozdania z Posiedzeń Komisji Polskiej Akademii Nauk, Oddział w Krakowie, 17, 236-237.
• TORSVIK, T.H., SMETHURST, M.A., MEERT, J.G., VAN DER VOO, R., MC KERROW, W.S., BRASIER, M.D., STURT, B.A. & WALDERHAUG, H.J. 1996. Continental break-up and collision in the Neoproterozoic and Paleozoic – a tale of Baltica and Laurentia. Earth Science Review, 40, 229-258.
• ZIJDERVELD, J.D.A. 1967. AC demagnetization of rocks: Analysis of results. In: D.W. COLLINSON & al. (Eds), Methods in paleomagnetism, pp. 254-287. Elsevier; New York.
• ŻABA, J. 1999. The structural evolution of Lower Palaeozoic succession in the Upper Silesia Block and Małopolska Block border zone (Southern Poland). Prace Państwowego Instytutu Geologicznego, 166, 1-162. [In Polish with English summary]