Wacław Florek, Stanisław Rudowski and Kazimierz Szefler
Palaeo-Valleys in the Region of the Słupia River Mouth
Basing on results of detailed hydroacoustic research, the geological structure of the bottom to 20-22 m b.s.l. has been studied. The palaeo-Słupia palaeo-valley, buried by a thin cover of marine sands, has been recognized and determined. Some stages of valley development may be distinguished. The deposits of the oldest valley are C14 dated at ca. 21 ka BP. But in the main stage, the valley was formed by action of the subglacial and thawing glacial waters during and after the so-called Gardno Phase. Most probably this valley was connected with the Pomeranian ice margin valley. The next stages of the valley's development were related with changes of the palaeo-Słupia under conditions of the Litorina transgression. The youngest palaeo-Słupia valley is, in the authors' opinion, related with a shallow, long incision, weakly marked in the sea bottom in the central part of the studied area. Field investigations were carried out by the Department of Operational Oceanography of the Maritime Institute in Gdańsk from the r/v Dr Lubecki. A DESO 15 echosounder, Subbottom Profilers model 3010 and the X Star system were used. Eight vibrocores (core length up to 3 m) were taken from the sea bottom and three borings (10-17 m depth) were executed on the shore. Accurate positioning was obtained using the DGPS and HYDRO and Track Point Systems. All data were digitally recorded and processed.
Wacław Florek, Jerzy Jonczak, Monika Niska and Iwona Pasamonik
Interdisciplinary studies on environmental evolution during the last 650 years based on the analysis of mill pond deposits have been conducted in the valley of the Jarosławianka Stream (left-bank tributary of the River Wieprza). According to historical data, confirmed also by radiocarbon dating, the water mill was located in the valley in 1351 and operated until the 1960s. The sequence of stratified deposits with a thickness of up to about 2 metres was accumulated in mill pond basin during this period. The vertical variability in the physical and chemical properties of these deposits reflects temporal environmental changes in the catchment, particularly the intensity of chemical and mechanical denudation and human activity. Analysis of subfossil Cladocera suggests four phases in the development of the mill pond. Changing along with the intensity of the pond basin water flow, redox and nutritional conditions are reflected in the spatial variability of deposits, especially their textural parameters, pH and abundance in organic carbon, nitrogen and carbonates.