Identification of a circular structure in eastern Pomerania (northern Poland) : a hypothesis of its origin

The possible existence of a circular structure in the Kościerzyna region (northern Poland) was suggested in two papers in the 1980s. The current studies were aimed at verifying this hypothesis. Analysis of a digital terrain model of the pre-Quaternary surface relief as well as of the present terrain revealed the existence of a large structure of ca. 50 km in diameter. Its geometry was established based on a model of the Neogene/Pliocene surface and identifiable lineaments. Its characteristic feature is the presence of rim-like forms, an internal plateau, and a “high” in the centre. The structure is estimated to date from before the Pleistocene. The circular structure has been reshaped by glacial erosion and accumulation, and is now buried under Quaternary deposits. The existence of the Kościerzyna circular structure was confirmed by conducted studies, but my hypothesis of an impact origin is still uncertain and needs to be confirmed by future research

The development of unconsolidated sedimentary coastal cliffs (Pobrzeże Kaszubskie, Northern Poland)

In the course of fieldwork based on geological and landslide mapping and spatial analyses of map information at least 2 types of landslides were identified. Type I: simple landslides developed in homogeneous and undisturbed rocks, for instance – loams, clays and sands. This type of landslide includes many examples developed mainly on the stretch (segment of the studied area) approximately between 132.25 and 133.50 km and 128.50 and 129.50 km of the Polish coastline. Type II: complex landslides in which the movement and displacement of rock masses occurs under complex geological and hydrogeological conditions. The complex factors are determined by phenomena such as glaciotectonics, discontinuities of rock layers and thrust zones; the slip surface occurs at considerable depths, and sometimes several slip surfaces can be distinguished. These landslide types are located in the vicinity of Jastrzębia Góra and Rozewie, near km 134 and 131.5. Prediction of the formation of this landslide types is difficult. Even if long-term observations are available, the mass movement, variable over time, is difficult to interpret. It is clear that the changes are continuous, but occur with varying intensity. Proper recognition of the types of mass movement is crucial to establishing the appropriate methods to prevent their development

Review and reinterpretation of the pollen and diatom data from the deposits of the Southern Baltic lagoons

According to their origin, geomorphology and hydrology, the fresh/brackish-water bays and coastal lakes of the Southern Baltic coast can be treated as lagoons. They developed at the time of and as a result of the Atlantic (Litorina) transgression of the Southern Baltica. There are many publications about the origin and evolution of the lagoons and lakes along the Polish coast of the Southern Baltic (e.g. Przybyłowska-Lange, 1973a, b, 1974, 1979, 1981; Zaborowska, 1977; Zachowicz, 1977, 1985; Wypych, 1980a, b; Zachowicz et al., 1982; Bogaczewicz-Adamczak, Miotk, 1985a, b; Dąbrowski et al., 1985; Zachowicz, Zaborowska, 1985; Borówka et al., 2001a, b, 2002). Nevertheless, the origin of the lagoons has not been fully explained. In the light of present-day information the results of earliest investigations often need to be reinterpreted. The aim of this work was the correlation of the published and unpublished pollen and diatom diagrams from Late Pleistocene and Holocene sediments of the Southern Baltic lagoons, and their relation with radiocarbon dating. The pollen and diatom diagrams from the area of north-east Germany and the Curonian Lagoon (Kabailiene., 1999; Jahns, 2000; Kaiser et al., 2000; Endtmann, 2002; Bitinas et al., 2002) have been used for comparison. For the palynological sites, the local pollen assemblage zones (L PAZ) have been identified according to Janczyk-Kopikowa (1987). Comparison of the biostratigraphical data allowed us to define the approach time of the formation of the lagoons in their present-day position on the coast as well as to determine the periods of an accelerated sea-level rise and increased frequency of storm surges (so-called marine transgression phases) when the investigated areas had been under the direct influence of the sea. Such influences are visible about 7000, 6000, 5000 and 4000 years BP. This period of marine influences, about 1000-year long, corresponds very well to the same period of climate oscillations mentioned by Stuiver and Braziunas (1993), Stuiver et al. (1995) and Chapman and Shackelton (2000). The influence of the sea in the Post-Litorina period was associated mainly with the inflow of sea water through more or less developed barriers, so they are not synchronous

A critical review and reinterpretation of bio-, litho- and seismostratigraphic data of the Southern Baltic deposits

The aim of this study was the reinterpretation of the published and unpublished Late-Pleistocene and Holocene pollen and diatom diagrams of deposits from the sedimentary basins of the Southern Baltic Sea and the correlation of the distinguished biostratigraphic units with lithological parameters, seismostratigraphic units. Chronostratigraphic subdivision of the Late Pleistocene and Holocene was also made. To facilitate the correlation and reinterpretation of the results of biostratigraphic (palynological and diatom) analyses, new unified and simplified diagrams were drawn using the POLPAL software. Such diagrams were constructed for all the sites under comparison, even for those of no numerical data. In such cases, the published diagrams were scanned and their percentage values were the basis for new diagrams. A review and reinterpretation of biostratigraphic data show an almost complete lack of palynological documentation and diatom diagrams for the Late Pleistocene period and poor documentation for the Early Holocene. Middle and Late Holocene Baltic muds have the best biostratigraphic documentation and radiocarbon dating, which greatly facilitates their location on the geological time scale. Among the Southern Baltic postglacial sediments three lithostratigraphic units were identified. They differ in their lithological features reflecting the conditions prevalent in the sedimentary basin during deposition. It should be noted that these units meet no formal criteria for distinguishing lithostratigraphic units. Similarly, within the Late Pleistocene and Holocene sediments of Southern Baltic deep-water basins, three main seismostratigraphic complexes have been identified. The integrated analysis of seismoacoustic profiles, lithological profiles of cores and reinterpretated biostratigraphic data allow a correlation of the bio-, litho- and seismostratigraphic units with chronostratigraphic units and Baltic evolutionary phases

Identification of the risks posed by mass movements in the urbanized areas of Gdansk and Gdynia

Celem artykułu było przedstawienie zasadniczych problemów kartograficznych przy rozpoznawaniu i dokumentowaniu osuwisk oraz terenów potencjalnie zagrożonych ruchami masowymi w obszarach miejskich Gdańska i Gdyni. Określenie lokalizacji i stopnia aktywności osuwisk oraz zagrożeń związanych z ich ponownym uruchomieniem wspomoże władze lokalne we właściwym zagospodarowaniu przestrzeni oraz wypełnieniu obowiązków dotyczących problematyki ruchów masowych wynikających z odpowiednich ustaw i rozporządzeń. Rozpoznanie lokalizacji i zasięgu osuwisk jest pomocne w tworzeniu planów odnoszących się do ryzyka osuwiskowego, czyli w ograniczeniu w znacznym stopniu szkód i zniszczeń wywołanych rozwojem osuwisk oraz zaniechaniu łub dostosowaniu budownictwa drogowego i mieszkaniowego w warunkach panujących w obrębie osuwisk.The aim of this article is to depict the fundamental cartographic difficulties towards appropriate recognition and evidence of landslides and areas potentially at risk of mass wasting, within urban zones of Gdańsk and Gdynia. Designation of landslide location, activity, and assessing a threat of landslide reactivation, is going to support the local authorities spatial planning accuracy - an obligation resulting from the adequate laws and regulations. A proper recognition of landslide location and coverage helps to apply suitable arrangements, aiming to reduce the damage caused by landslide development, as well as omission, or adaptation of road construction and housing, within areas being at risk of mass wasting and landslide activity

A Holocene sea-level database for the Baltic Sea

AbstractWe present a compilation and analysis of 1099 Holocene relative shore-level (RSL) indicators located around the Baltic Sea including 867 relative sea-level data points and 232 data points from the Ancylus Lake and the following transitional phase. The spatial distribution covers the Baltic Sea and near-coastal areas fairly well, but some gaps remain mainly in Sweden. RSL data follow the standardized HOLSEA format and, thus, are ready for spatially comprehensive applications in, e.g., glacial isostatic adjustment (GIA) modelling. We apply a SQL database system to store the nationally provided data sets in their individual form and to map the different input into the HOLSEA format as the information content of the individual data sets from the Baltic Sea area differs. About 80% of the RSL data is related to the last marine stage in Baltic Sea history after 8.5 ka BP (thousand years before present). These samples are grouped according to their dominant RSL tendencies into three clusters: regions with negative, positive and complex (transitional) RSL tendencies. Overall, regions with isostatic uplift driven negative tendencies dominate and show regression in the Baltic Sea basin during the last marine stage. Shifts from positive to negative tendencies in RSL data from transitional regions show a mid-Holocene highstand around 7.5–6.5 ka BP which is consistent with the end of the final melting of the Laurentide Ice Sheet. Comparisons of RSL data with GIA predictions including global ICE-5G and ICE-6G_C ice histories show good fit with RSL data from the regions with negative tendencies, whereas in the transitional areas in the eastern Baltic, predictions for the mid-Holocene clearly overestimate the RSL and fail to recover the mid-Holocene RSL highstand derived from the proxy reconstructions. These results motivate improvements of ice-sheet and Earth-structure models and show the potential and benefits of the new compilation for future studies.</p