THE SHELLY SARMATIAN-BEDS IN THE RÂMNICU SĂRAT BASIN (JITIA DE JOS, VRANCEA COUNTY)

Abstract. The Sarmatian shell-beds of the Râmnicu Sarat river basin (Carpathian Foredeep) account for significant features that can help decipher the paleoenvironmental conditions in the sedimentation basin. The accummulation of the monotaxic – even monospecific – molluscs valves (e.g. extraordinary abundance of the Mactra caspia) seem to originate from prolonged conditions of high energy littoral events, like the storm induced currents. The sedimentary structures displayed by the shell beds indicate that the transport and sedimentation of the shelly material took place within a shallow water, littoral environment. The shells/sandy matrix ratio probably expresses the energy level of the transporting currents

Geo-ecological Assessment of Tuzla Lake (Constanţa County, Romania)

Abstract. Tuzla Lake emerged in the 70’s as an extension of Techirghiol Lake. The forming of the lake occurred due to human factors (intensive irrigations) and was favoured by natural factors (years of intense pluvial regime). The periodical increase of the Tuzla Lake level produced flooding in the area; the most recent ones (September 2005) significantly affected the buildings and the land around Tuzla Town. In order to evaluate the geo-ecological state of Tuzla Lake, including the impact from the last flooding events on the morphology of the lacustrine basin, the following investigations were performed: bathymetry measurements, sedimentological evaluations, and determination of the physico-chemical, chemical and microbiological parameters of the water. These investigations were performed during 2005 and 2006, and they consisted of the periodical sampling of the water and sediments as well as of bathymetry measurements sensu stricto before and after the 2005 flooding events. The central area of Tuzla Lake has a positive morphological element directed N-S, which divides the basin of the lake in two distinct areas: a western area, maximum 2m deep, and an eastern area, over 1.5m deep. Following the September 2005 floods, a decrease in the depth of the lake by 60-70cm in the southern part of the lake and by 30cm in the northern part occurred. Probably, one of the effects of the flood was the partial clogging of the lake. The lithology of the samples analyzed (mud, silt) indicates that the Tuzla Lake sediments are specific to a lacustrine environment. The aquatic environment is eutrophic (high level of nutrients and reduced oxygen level), an environment suggested by the blackish colour and the oily consistency which is specific to the sapropelic muds. The laboratory analysis results indicate low values for dissolved oxygen, and values significantly above the standards for PO4 2, SO4 2-, as well as high salinity values (30-40 ‰). Therefore, it was concluded that the water in Tuzla Lake is polluted. This observation, along with the fact that there was an excess of lake vegetation that favoured an increase in anophelic habitats, indicates the fact that Tuzla Lake presents a hazard for the human health of the communities in the area

Danube River: sedimentological, mineralogical and geochemical characteristics of the bottom sediments

Abstract. For a better understanding of the recent pollution in the lower Romanian sector of the Danube and its relations with human activities, yearly investigations have been carried out on 50 cross sections, between km 1072 - Bazias and the Danube mouths, using R/V Istros. The field activity was performed on three main sections, each with different geological, morphological and hydrological features: Iron Gates I and II dam lakes, km 845 – Mile 44, and the Danube Delta area. Physical and chemical investigations were performed on bottom sediment and surface water samples. Biological samples were collected and investigated as well. The 2005 results allowed an assessment of the Danubian aquatic environment, the comparison of present and previously collected data and the identification of significantly sensitive areas. Mitigation strategies according to the EU requirements are proposed