Wgłębna budowa geologiczna środkowej i zachodniej części synklinorium północnosudeckiego w świetle nowych danych

Abstract

Przedstawiono przegląd serii skalnych środkowej i zachodniej części synklinorium północnosudeckiego oraz krótko omówiono rozwój i wgłębną budowę geologiczną tego obszaru. Wykorzystano nowe dane uzyskane przy poszukiwaniu złóż rud miedzi oraz innych pracach wiertniczych i geofizycznych. Dane te wraz z reinterpretacją starszych materiałów posłużyły do zestawienia nowej wersji odkrytej (bez utworów kenozoicznych) mapy geologicznej. Przedstawiono na niej ważniejsze z podrzędnych struktur tektonicznych wieku laramijskiego, natomiast na załączonych przekrojach geologicznych - struktury starsze: palatynackie i eokimeryjskie.DEEP GEOLOGICAL STRUCTURE OF CENTRAL AND WESTERN PARTS OF THE NORTH-SUDETIC SYNCLINORIUM; SOME NEW DATAThe paper presents a brief characteristics of rock series of central and western parts of the North-Sudetic Synclinorium (Lower Silesia) and an attempt to sUJIlDl8.l"izxi the history and deep geological structure of this area.The North-Sudetic Synclinorium is a structural unit of the north-western Kaczawa metamorphic massif, the generation of which is dated at the Late Carboniferous. In the Rotliegendes times, the Synclinorium area was characterized by diastrophic sedimentation of clastic deposits with intercalations of volcanic rocks, better developed further to the north, and temporarily broken by erosion related Saalian phase movements. Subsequently, an embayment of epicontinental Zechstein sea entered the area. Palynological analysis of Zechstein rocks from the borehole N-24 Bolesławiec showed the presence of the Werra and Stassfurt. Higher links of the Upper Permian are presumably developed in continental facies in major part of the Synclinorium, which may be explained by uplift of that area in result of Palatinian phase movements. A depression with labile floor originated at south-western margin of the Fore-Sudetic Block in the Early Bundsandstein. The depression was temporarily flooded which is indicated by carbonates present at the top of the Lower Bundsandstein. These deposits are overlain by thick clastic series of the Middle- Bundsandstein. Successive marine transgression began in the Rhöt. Eocimmerian movements resulted in division of the Synclinorium into several block structures and initiated new period or erosion. Cenomanian sea entered deggradated area·and the Cenomanian rests on various links of the Triassic. Clastic-carbonate sedimentation continued till the Santonian when the sea retreated due to first Laramie movements. The movements are responsible for the main features of the present tectonics of the North-Sudetic Synclinorium. Laramie structures (subdivided and slightly transIocated along younger faults) are shown on the map of Cenozoic subcrops, based on the results of new drillings and geophysical surveys. The geological cross-sections through the Synclinorium area (Fig. 2) show the presence of older, Palatinian and Eocimmerian faults within the Laramie structures.The type of geological structure of central and western parts of the North-Sudetic Synclinorium appears similar to that known from the eastern part Further drillings and geophysical surveys are necessary for a more detailed analysis of the deep structures.