Krakowidy jako górotwór kaledoński

Czesław Haranczyk



The paper presents description of flysch-like rock series found by drillings in the Dolina Będkowska area and at Kwaśniów and Pilica, and dated at the Lower Cambrian on the basis of the recorded Acritarcha, Middle Cambrian rocks, Ordovician limestones and intercalating siliceous shales, and Silurian flysch rocks from the Zawiercie area. Sedimentary environments of these rocks are shown to be entirely different from those of coeval strata from the Holy Cross Mts, Małopolska Massif and Upper Silesian Massif. Moreover, conglomerates of the mountain valley alluvium type, resting on the folded Caledonian orogen and overlain by Lower Devonian quartzites, are described from the Zawiercie area.
Two zones are differentiated in the Cracovide orogen: a meridional Cracow-Pilica zone, formed due to movements of the Sandomirian tectonic phase, and WNW - ESE oriented, i. s. transversal to the former, Lubliniec-Działoszyce zone, folded in the Cracow phase. The results of analysis of lithological development of rocks, reoccurrence of Cambrian strata in the borehole RK-1 (Zawiercie), resulting from overthrusting, and tectonic contact of Cambrian and Silurian rocks found beneath Lower Devonian quartzites at Zawiercie make it possible to state that the Cracovides represent an epigeosynclinal Caledonian fold belt, transformed into horst mountains in result of Variscan movements. The denivellations of the horst mountains were up to 5 km, e.g. in the case of the Jerzmanowice crest. The mountains were subsequently cut by strike-slip faults following older, Caledonian directions. Slip planes of the faults are common in core material.
Fissures related to successive rejuvenations of the strike-slip faults appeared predestinated for intrusions of Caledonian igneous bodies, veins of Variscan subvolcanic porphyries and necks of volcanic apparatuses of Variscan age, as well as several generations of mineral veins: Caledonian polymetallic mineralization, Variscan mineralization of Cu-Mo porphyry-deposits, and finally mineralization of Zn-Pb ore deposits. The magmatism of alkaline-calcium petrographic province and the ore mineralization were interpreted as related to the presence of ancient Benioff zone, situated west of the Tornquist-Teisseyre line.

Full Text:

PDF (Polish)