Tektonika środkowo-południowej Polski pozakarpackiej

Abstract

Opisano przedemskie podłoże: w masywie Górnego Śląska (1) zbudowane z prekambryjskich zasadowych i kwaśnych plutonitów i wulkanitów, z gnejsów i metaskał; w strefie Lublińca - Zawiercia - Krakowa (2) zbudowane z prekambryjskich i kambro-sylurskich łusek skał osadowych i metaskał oraz z kwaśnych i zasadowych plutonitów i wulkanitów; w Niecce Nidziańskiej i przedkarpackim zapadlisku (3), gdzie budują je prawie wyłącznie prekambryjskie metaskały, z wulkanitami, oraz w Górach Świętokrzyskich (4), które zbudowane są głównie z kambro-sylurskich skał, wyłącznie osadowych, z zasadowymi wulkanitami. Strefa pierwsza reprezentuje masyw międzygórski, do którego przyrasta synklinorium Lublińca - Zawiercia - Krakowa. Strefę trzecią zinterpretowano jako geantyklinę przekształconą w orogenezie kaledońskiej w antyklinorium. Góry Świętokrzyskie reprezentują kaledońskie synklinorium wypiętrzone n a p r z e ł o m i e  kar b o n u - p e r m u jako góry załomowe i odmłodzone orograficznie w epoce alpejskiej. Podłoże opisanych jednostek należy do Vistulicum obejmującego również podłoże przedemskie Kujaw, Wielkopolski i Pomorza Zachodniego.TECTONICS OF SOUTHERN PART OF MIDDLE POLAND (BEYOND THE CARPATHIANS) The pre-Emsian basement in the Upper Silesian massif = the basement of the Silesian-Cracow Foredeep (1), the Lubliniec-Zawicrcie-Cracow zone (2) and the Nida trough and the Carpathian Foredeep (3) as well as the pre-Emsian rocks which build the Holy Cross Mts (4) are described in the paper. There are only Precambrian basic and acid plutonic and volcanic rocks, gneisses and different metarocks in the Upper Silesian massif. The basement of the second zone is formed by mainly Cambro-Silurian sedimentary and metasedimentary rocks with basic and acid plutonic and volcanic rocks. The basement of the third zone is only composed of the Precambrian metasedimentary and volcanic rocks while the mainly Cambro-Silurian and solely sedimentary rocks with pre-Emsian diabases and lamprophyres form the Holy Cross Mts. The basement of the Upper Silesian Foredeep (1) is the intermediary massif, and the Lubliniec-Zawiercie-Cracow synclinorium (Cracovides) is adjoining it. The next zone (3) is interpreted as geanticline which during the orogenesis was transformed into anticlinorium. The Holy Cross Mts represent a synclinorium which was risen up as fault-block mountains during the Variscan epoch and orographically rejuvenated during the Alpine epoch. In numerous boreholes sequences; of the Lubliniec-Zawiercie-Cracow zone the alternation of metamorphic and sedimentary series of the same age was recorded This indicates the decollement and overthrust of complexes of metarocks on complexes of sedimentary rocks and, next, the common folding and thrusting into slice folds, so generally it indicates the great spatial compression of the rocks of the Caledonian geosyncline. The pre-Emsian erosion of the Caledonian orogen and the present spatial distribution of Precambrian and Cambro-Silurian rocks below the transgressive Devonian deposits permit to draw the structural conclusions. The Holy Cross Mts which are mainly built of the Cambro-Silurian rocks are a synclinorium system while the folded basements of the Nida trough and Carpathian Foredeep form an anticlinorium system in which the general absence of the Cambrian and Tremadocian rocks is secondary. The intensity of sedimentation of Cambrian and Tremadocian deposits on the submarine geanticline had to be evidently very limited. The uplift of the geanticline and its transformation into anticlinorium system during the Sandomirian phase (on the turn of Tremadocian and Arenigian, recte in the lowermost Arenigian) initiated the deep-reaching erosion which removed thin Cambrian and Tremadocian deposits. The Lubliniec-Zawiercie-Cracow synclinorium which is mainly built of the Cambro-Silurian sedimentary rocks and metarocks, accretes with that anticlinorium from west and south-west. Stronger metamorphosed rocks of the synclinorum were pulled deeper and even tectonically sucked in at the contact with the crystalline Upper Silesian massif. The basement of the described units belong; to V I s t u I i cum (H. Stille, 1950) which as the widespread area of Caledonian consolidation also comprises the basements of Kujawy, Wielkopolska and Western Pomerania (J. Znosko, 1962, 1964, 1974; R. Dadlez, 1974). From the primary bigger area of the Caledonian development those zones have been later excluded which were subjected to Variscan regeneration or continuation. This refers to Sudetes. also to those which now occur below the sedimentary cover.