Abstract Several years of weekly sampling of waters from the Shinfa River watershed in the lowlands of northwestern Ethiopia yielded 275 samples with δ D vsmow and δ 18 O vsmow values ranging from c. −10 to +100‰ and from c. −2 to +20‰, respectively. Wet season (summertime) Shinfa River water stable hydrogen and oxygen isotope values are among the lowest reported in this study, whereas the dry season (winter/spring) usually records a progressive trend towards +100 and +20‰, respectively. Overlapping with this interval of Shinfa River water sampling, air temperatures ( n = 155) also were recorded at the same time; temperatures range from c. 18 to 47°C. The coolest temperatures occur during the summer wet season, associated with the arrival of the Kiremt rains in the region, whereas the warmest temperatures occur towards the end of the dry season. In order to evaluate the extent to which this rather extreme isotope hydrology is recorded in the sediments and biota of the Shinfa River system, both hardwater calcareous deposits precipitated on basalt cobbles by evaporation in the Shinfa River channel during the dry season and aragonite from three different modern bivalve mollusc species were collected and analysed for their stable oxygen and carbon isotope compositions. Hardwater calcareous deposit δ 18 O vpdb and δ 13 C vpdb values range from c. −2 to +5‰ and c. −9 to +7‰, respectively, and preserve a trend towards progressively more positive δ 18 O vpdb and δ 13 C vpdb values through the course of the dry season. Shinfa River mollusc aragonite powders ( n = 51) were serially sampled from cf. Coelutura aegyptica , cf. Chambardia rubens and Etheria elliptica species. All species record oxygen and carbon isotopes between c. −2 and +7‰ and between c. −18 and −8‰, and each species records coherent trends between those extremes as well as a positive parametric correlation between measured oxygen and carbon isotope values. However, there does appear to be some variability of measured isotope values by species, suggesting that species-specific metabolic differences may impact the resulting range of aragonite stable carbon and oxygen values. Based upon the measured Shinfa River water δ 18 O vsmow and corresponding water temperatures at the time of sampling, a possible range of Shinfa River calcite and aragonite δ 18 O vpdb values were calculated in conjunction with well-established calcite–water and aragonite–water oxygen isotope fractionation equations. These ‘fictive’ calcite and aragonite δ 18 O vpdb values range from c. −5 to +15‰, which is a much larger range than previously documented from analyses of the hardwater calcareous deposits and mollusc aragonite samples. The narrower range of values in the natural calcite and aragonite samples may be attributed to several mechanisms, including time averaging and environmental stress. Nevertheless, the stable oxygen isotopic compositions of these natural samples offer a minimum assessment of the environmental extremes which occur in this region today, and provide a model for reconstructing the environments of the past.

Abstract The Norwegian coast facing the Atlantic Ocean was ice free as early as the Allerød oscillation in the late Pleistocene. The landscape was probably habitable for humans. It has, therefore, been assumed by several scholars that this coastline was visited or inhabited from the Late Glacial period onwards. In part, this argumentation is based on the presumed proximity of the Norwegian mainland and Doggerland, which existed between present-day Denmark and Great Britain because of a much lower global sea level. The aim of this paper is to examine the 14 C dates available from the oldest Norwegian settlement sites, and to compare them to the Quaternary processes of deglaciation and sea-level change. The hypothesis is advanced that humans did not settle in present-day Norway before a sheltering passage of islands and peninsulas had developed between the Swedish west coast (Bohuslän) and the Oslo area. This happened in the second half of the Preboreal period, at approximately 9.3 cal ka BC, or in the final centuries of the tenth millenniun BC. Supplementary material: 14 C dates used in Figures 2, 4 and 9 are available at http://www.geolsoc.org.uk/SUP18779 .

Abstract The region of NW Russia connecting with the Baltic Sea presents a dynamic ecological system that was sensitive to environmental changes during the Holocene. Certain factors affected environmental changes in the region during the Holocene: deglaciation processes, that finally terminated about 9 cal ka BP; eustatic sea-level changes; and tectonic movements, which are basically considered in the region as isostatic uplift processes. Contextual remains of ancient human occupation sites can be the only evidence of surface stabilization in monotonous sediments, such as aquatic and subaquatic deposits. Prehistoric settlements also mark ancient shorelines. The latter is of great importance for studying the history of water oscillations and coastal-line displacements on the territory of NW Russia. The transgressive–regressive stages of the Baltic Sea (at c. 10.15 cal ka BP, the Ancylus transgression; at c. 7.6–7.0 cal ka BP, the Littorina transgression) have an impact on the positions of prehistorical sites. The complex investigations of the Stone Age archaeological settlements on the Karelian Isthmus and in the Dvina–Lovat’ basin, and their altitudes below sea level, allowed us to reconstruct palaeoenvironmental changes during the Holocene, the chronology of cultural–historical processes and the adaptation strategy of ancient people to environmental conditions in this territory.

Coastline changes are the result of the interaction between geosystems and climate. Vertical isostatic movement of Earth's crust competes with the eustatic sea-level variation controlled by changing climatic conditions. The resulting relative sea-level variation has a vital impact on the anthroposphere along the sea coast. This interrelation can be studied in an exceptional manner on the southern Baltic Sea. Here, isostasy and eustasy have shaped the picture of the coastal areas since the last glaciation. The northern Scandinavian part has been uplifting constantly since the last deglaciation, causing a regression of the sea. In contrast, in the south, the Littorina transgression has initiated land loss due to the glacio-isostatically sinking coast. Human populations living along the coast since Mesolithic time have reacted by relocating settlements. This migration is well documented and preserved at the Wismar Bight, Germany, by submarine archaeological remnants. Dates of samples from ancient coastlines, supported by geostatistical methods to estimate sediment transport processes, allow us to model the paleogeographic settings on a local scale using maps. By projecting the investigated processes into the future, scenarios of predicted coastline evolution can be modeled. Extrapolated isostatic measurements and sea-level data derived from IPCC (Intergovernmental Panel on Climate Change) scenario A for the next 800 yr are superimposed in order to estimate areas that may sink below the sea level.