Analiza paleotektoniczna paleogeńskiej i neogeńskiej aktywności północnych fragmentów strefy dyslokacyjnej Poznań–Oleśnica
Abstract
Palaeotectonic analysis of the Paleogene and Neogene activity of the northern parts of the Poznań-Oleśnica Dislocation Zone. (central Poland).
S u m m a r y. Northern part of the Poznań–Oleśnica Dislocation Zone (SDP–O), including Mosina and Naramowice grabens, is located between Czempiń and northern districts of Poznań. In this article, the aim of study is to determine the Palaeogene and Neogene tectonic evolution of both grabens. Basing on combination of cross-sections and aggradation coefficient — AC analysis, three periods of tectonic subsidence were recognized. The first one took place from the Lower Mosina Formation to the Upper Mosina Formation sedimentation with maximum development during the Czempiń Formation accumulation (Lower Oligocene). During the Ścinawa Formation (Middle Miocene, the lower part) sedimentation the study area was affected by the second period of tectonic subsidence. The last period of the Naramowice and Mosina grabens tectonic evolution is not exactly known. However, this its timing may be determined. It lasted after the Middle–Polish Member, lower part of the Poznañ Formation, and before the Pleistocene glacial sedimentation (after the middle part of the Middle Miocene). Finally, these periods of tectonic subsidence in the northern fragment of the SDP–O are correlated with tectonic phases recognized by Stille (1952). The first two periods relate to Pyrenean and Styrian (Early Styrian) phases. The third one may be connected to post-Moldovian (post-Late Styrian) phase or phases (Attican, Wallachian, etc.).
S u m m a r y. Northern part of the Poznań–Oleśnica Dislocation Zone (SDP–O), including Mosina and Naramowice grabens, is located between Czempiń and northern districts of Poznań. In this article, the aim of study is to determine the Palaeogene and Neogene tectonic evolution of both grabens. Basing on combination of cross-sections and aggradation coefficient — AC analysis, three periods of tectonic subsidence were recognized. The first one took place from the Lower Mosina Formation to the Upper Mosina Formation sedimentation with maximum development during the Czempiń Formation accumulation (Lower Oligocene). During the Ścinawa Formation (Middle Miocene, the lower part) sedimentation the study area was affected by the second period of tectonic subsidence. The last period of the Naramowice and Mosina grabens tectonic evolution is not exactly known. However, this its timing may be determined. It lasted after the Middle–Polish Member, lower part of the Poznañ Formation, and before the Pleistocene glacial sedimentation (after the middle part of the Middle Miocene). Finally, these periods of tectonic subsidence in the northern fragment of the SDP–O are correlated with tectonic phases recognized by Stille (1952). The first two periods relate to Pyrenean and Styrian (Early Styrian) phases. The third one may be connected to post-Moldovian (post-Late Styrian) phase or phases (Attican, Wallachian, etc.).